ROTEX GasSolarUnit · 2017. 10. 31. · The ROTEX GSU/GCU is a gas fired condensing boiler (A), that is integrated in a 500 litre DHW cylinder (B). The DHW cylinder is filled with

R O T E X G a s S o l a r U n i t :Gas fired condensing boiler with solar stratification cylinder.

R O T E X G a s C o m p a c t U n i t :Gas fired condensing boiler with high performance domestic hot water cylinder.

I n s t a l l a t i o n a n d m a i n t e n a n c e i n s t r u c t i o n s f o r c o n t r a c t o r s .

Type Rated thermal load

ROTEX GSU 25 5–25 kW modulating

ROTEX GSU 35 8-35 kW modulating

ROTEX GCU 25 5–25 kW modulating

ROTEX GCU 35 8–35 kW modulating

Serial number

Customer

GB0085 BM0065

C o n t e n t s

Introduction

The ROTEX GasSolarUnit/GasCompactUnit is a completely installed gas fired condensingheating system with integral domestic hotwater (DHW) heating system. All DHW andcentral heating functions for the direct connected and an optional mixed heating circuit as well as for one cylinder primary circuit are automatically regulated by the standard micro-controller. For even higher convenience, a digital room station (ROTEXTHETA RS, part no. 15 70 18) and a room controller set (THETA RFF, part no. 154070) areavailable as option.

A further mixed heating circuit and/or cylinderprimary circuit can be operated in conjunctionwith the optionally available heating circuitextension module (THETA HEM1, part no. 15 60 61).

Every parameter required for a convenientoperation has already been programmed at thefactory. Except for the operation of the controlunit (separate instruction manual is part of thestandard delivery), all activities and controlsrequired for the installation, commissioning,operation and individual adjustment aredescribed in the following.

The ROTEX GasSolarUnit includes a high-gradesolar stratification cylinder as standard. Thesystem can therefore, with only few additionalcomponents, extended to become a solar heat-ing system with solar DHW heating and solarcentral heating backup. Your ROTEX specialistwill be happy to provide your with furtherinformation.

With the GasCompactUnit, the entire cylindervolume is utilised as high performance DHWcylinder. It is not designed for direct solarapplications.

Please read these instructions carefullybefore commencing the installation orprior to working on the system.

The installation, connection and commission-ing must be carried out by an authorised contractor. Afterwards, the system should behanded over by the installer to the user. Forthis, the user must be instructed in the operation and control of the heating equipment. The handover should be recordedby jointly completing and signing the installation and training form supplied.

The symbol and further warning symbolshighlight safety information. The symbolidentifies text passages that are particularlyimportant to achieve an optimum utilisation(adjustments, monitoring, etc).

Chapter 1: Safety instructions and warranty statement 3

Safety instructions 3General warranty terms 4Declaration of conformity 4

Chapter 2: General function and Component description

2.1 Principle of operation 52.2 Component description 8

Chapter 3: Positioning and installation

3.1 Delivery 123.2 Installation versions 12

Information regarding the installation in garages 12General information regarding the flue gas system 13

3.3 Positioning 15

3.4 Connecting the GasSolarUnit 16Connection of the flue gas and ventilation air lines 16Flue outlet straight out of the back 16Flue outlet out of the side and back 16Flue with roof outlet 18Supplementary assemblies 18Connection of heating and DHW lines 18Low water indicator 18Connection of the gas supply pipe - checking the gas type and burner settings 19Connection, condensate drain 20Connection, electrical cables/leads 20Temperature sensor connection 21Pumps, three-way diverter valve 22Optional connection options 22Mixer circuit connectionRoom thermostat connectionRoom station connection

3.5 Filling 23DHW heat exchanger 23Unpressurised cylinder 23Heating circuit 23

3.6 Initial start-up 24Testing the high limit safety cut-out 24

3.7 Standards and guidelines 24Check list prior to commissioning 25Check list post commissioning 25

Chapter 4: Boiler control panel

4.1 Brief description 264.2 Manually adjusting the boiler

water temperature 284.3 Replace control unit 284.4 Replacing the boiler control panel 294.5 Replacing the cables/leads and sensors304.6 Replacing the fuse 324.7 Replacing the PCB 324.8 Component layout - wiring diagram 32

[ 2 ]

Chapter 5: Technology

5.1 Gas burner 34Construction 36Resetting the burner 36Burner output 36Gas:air mixture control 36Checking the burner adjustment 36Adjusting the burner and matching the burner to the gas type 38Gas type conversion 40Limiting the max. burner output 40Selecting the min. burner output 40Adjusting the ignition and ionisation electrodes 41

5.2 DHW cylinder 41Optimum water hygiene 42Corrosion resistant and low on maintenance 42Low susceptibility to scaling 42Economical to operate 42Stratification inside the cylinder 42

5.3 Hydraulic system connection 43

Chapter 6: Inspection and maintenance

6.1 Inspection and maintenance work 496.2 Temporary shutdown 51

Draining the system 51Draining the cylinder 51

Chapter 7: Troubleshooting

Troubleshooting 52

Chapter 8: Specification

Specification GSU/GCU 56Maintenance log 63

Chapter 9: For the flue gas inspector

Flue sizing details 64

Safety

The ROTEX GasSolarUnit (GSU)/ GasCompactUnit (GCU) is designed exclusively for

heating hot water heating systems.

Carry out all installation, inspection, maintenance and repair work in line withthese instructions. Strictly observe allsafety requirements and regulations, towhich these instructions refer. Non-observation or incorrect operation canresult in dangerous situations with risks tohealth, individuals, equipment and thebuilding.

Before any work on the heating system,switch OFF the mains electrical isolatorand protect against unauthorised reconnection.Any work on the heating system must onlybe carried out by authorised and appropriately trained personnel (heatingcontractor). Observe all applicable Health& Safety and accident prevention regulations.

The electrical installation must only becarried out by an authorised electrician,who must observe all local and nationalregulations. In addition, observe therequirements specified by the relevantelectricity supply company.

Maintain the minimum clearancestowards walls and other objects asdetailed in chapter 3.When installing the ROTEX GasSolar-Unit/GasCompactUnit ensure, that thefloor can bear a load of at least 1050 kg/m2

and provides a sufficiently sizeable safetymargin. Check the correct installation ofthe temperature sensor and the pressuregauge prior to commissioning.

The GasSolarUnit/GasCompactUnit mustonly be operated with fitted thermal insulation and/or silencer hood (risk ofburning).

Before connecting the equipment to thepower supply, compare the rated voltagestated on the type plate (230 V, 50 Hz) withthe supply voltage. Install this heating system in accordance with the safetyrequirements in EN 12828 as an open orsealed system.

All safety valves must be compliant withDIN EN ISO 4126-1 and must be type-tested. The blow-off line must correspond to the highest rated output ofthe ROTEX GasSolarUnit/GasCompactUnit.

In sealed systems, use only safety valvesmarked with an “H” in the type-test symbol. Install them in the safety flow. For filling and commissioning the heating system, observe VDI 2035 [or local regulations].

The ROTEX GasSolarUnit/GasCompactUnithas been tested and certified in accor-dance with DIN EN 483, DIN EN 677 andDIN EN 625.

The GasSolarUnit/GasCompactUnit is categorised as NOx class 5. It performssubstantially better than the minimum efficiency for condensing boilers specifiedby EN 677. It meets the requirements ofthe 1st BImSchV and those of the “BlueAngel” RAL-UZ 61 [Germany].

For connection to the sanitary systemobserve the regulations in DIN EN 806 andDIN 1988 [or local regulations]. The connecting pressure should not exceed 6 bar and must, under no circumstances,be higher than 10 bar. When installing gasfired heating systems, observe TRGI G 600,TRF or the respectively applicable nationalregulations, as well as the requirements ofthe gas supply company.

The gas supply pressure should bebetween 5 and 55 mbar.Compare the gas details specified on theequipment label with the supply detailsspecified by your gas supply company.

[ 3 ]

C h a p t e r 1 : S a f e t y i n s t r u c t i o n s a n d w a r r a n t ys t a t e m e n t

Never remove or damage lead seals.

Only use flue gas systems approved forcondensing operation. Only use the burner when an adequatesupply of combustion air is assured. Thisis automatically assured, if the Gas-SolarUnit/GasCompactUnit is operated inbalanced flue mode with a concentric balanced flue system sized in accordancewith the ROTEX standard; there are noother conditions specified for the installation room.

Without balanced flue system, never operate the burner in rooms with aggressive vapours (e.g. hair spray,trichloroethylene, tetrachlormethane),severely dusty (e.g. workshops) or highlyhumid conditions (e.g. laundries). A ventilation aperture to the outside measuring at least 150 cm2 must be provided.

Prior to the commissioning, fill the cylinder(unpressurised area) with water, otherwise flue gas could enter the installation room.

Also carefully observe all warnings identified in the following chapters withthe -symbol or other warning symbols.

Any modification of the equipment canresult in dangerous conditions. Suchmodifications are therefore only permissible with the written authorisationfrom ROTEX.

General warranty terms

ROTEX is liable for all material and manufacturing faults in line with this statement.Within the warranty period, ROTEX will repairthe equipment free of charge through anauthorised contractor.

ROTEX reserves the right to supply replacement equipment. The warranty onlyapplies if the equipment has verifiable beencorrectly installed by a qualified contractor. As verification, we strongly recommend thatthe installation and instruction form suppliedis completed and returned to ROTEX.

Warranty periodsThe warranty period commences with the dateof installation (invoice date of the installingcontractor), but no later than six months afterthe date of manufacture (invoice date). Thewarranty period will not be extended by thereturn of the equipment for repair or replacement.

Warranty: 2 years

Warranty exclusionsNon-authorised interference with the equip-ment, incorrect installation and modification ofthe equipment result in the immediate loss ofany warranty claim.

All despatch and transport losses are excludedfrom the warranty.

The warranty explicitly excludes all consequential losses, in particular costs associated with the removal and installation ofthe equipment.

All other costs, in particular claims for compensation, are excluded.

The warranty does not cover parts that aresubject to normal wear and tear (acc. to themanufacturer’s definition), e.g. indicators,switches, fuses).

[ 4 ]

DECLARATION OF CONFORMITYfor the condensing heating centres ROTEX GasSolarUnit and ROTEX GasCompactUnit

We, ROTEX GmbH, declare in sole responsibilitythat the following product

Product Part no.ROTEX GasSolarUnit GSU 25 15 70 10ROTEX GasSolarUnit LPG GSU 25 F 15 70 20ROTEX GasSolarUnit GSU 35 15 70 21ROTEX GasSolarUnit GSU 35LPG GSU 35 F 15 70 23ROTEX GasCompactUnit GCU 25 15 70 30ROTEX GasCompactUnit LPG GCU 25 F 15 70 35ROTEX GasCompactUnit GCU 35 15 70 40ROTEX GasCompactUnit LPG GCU 35 F 15 70 45

with the product ID CE-0085 BM0065complies, in its standard form, with the following

European Directives:89/336/EEC Electromagnetic

Compatibility90/396/EEC EC Gas Equipment

Directive73/23/EEC EC Low Voltage Directive92/42/EEC EC Efficiency Directive

Güglingen, 1.7.2005 Dr.-Ing. Franz Grammling

2.1 General function

Fig. 2.1.1 on page 6 indicates the equipmentGSU layout in diagrammatic form. Fig. 2.1.2 onpage 7 shows the GCU in diagrammatic form.Tab. 2.2.1 summarises the legends used in thefigures.

The ROTEX GSU/GCU is a gas fired condensingboiler (A), that is integrated in a 500 litre DHWcylinder (B). The DHW cylinder is filled withunpressurised water (C).Inside the cylinder is a spiral heat exchangermade from a corrugated stainless steel pipe(18) that is drawn from the cylinder floor to thetop. This generates the required domestic hotwater.

When there is sufficient sunshine, the DHWcylinder of the GSU can also be heated withsolar power (accessories – ROTEX Solaris).When the available solar energy is insufficient, the gas fired condensing boilerwill reheat the cylinder water via a corrugatedstainless steel pipe heat exchanger (19),through which the heating water flows fromtop to bottom.

When heating with the gas fired condensingboiler of the GSU, deliberately only the upperzone of the cylinder is held at the selectedtemperature. Subject to the available solarenergy, the entire cylinder can be heated withsolar power, ensuring that the stored energy isutilised both for DHW heating and for centralheating backup.

The boiler is integrated in the DHW cylinder,consequently there are no surface or cool-down losses. The heat is completelytransferred to the cylinder water and not to theambience. In addition, the excellent thermalinsulation of the plastic cylinder ensures minimum thermal losses.

The GSU is split into 3 zones:Zone 1 (upper zone): DHW zone (D)Zone 2 (lower zone): Solar zone (E)Zone 3: Central heatingbackup (open zone (F) thermally insulated (towards the area inside zone 1) bottom)

The GSU can provide comfortable hot water atany time. Simultaneously, solar energy can bestratified for DHW heating and central heatingbackup. The large (500 litres) capacity of thecylinder also enables the bridging of longertimes without sunshine.

With the GCU, the entire cylinder content isdesigned as DHW zone to make the highestDHW output available. Any associated thermalutilisation of solar energy is recommended inconjunction with a Solaris system (pre-heatstage) upstream of the GCU.

The arrangement and flow pattern of the heatexchangers creates a distinct temperaturestratification on all devices. That results inhigher energy yields.

The output is variably regulated by the electronic control units GSU 25 (GSU 35)/GCU25 (GCU 35), modulating from minimum 5 (8) tomaximum 25 (35) kW. The GSU/GCU flexiblymatches its output to changing conditions. The internal microprocessor control managesthe output.The flue gas temperature remains below 90 °Cat all times.

The energy contained in the fuel gas is utilisedto its optimum by the condensing technology.In this process, the flue gas inside the boilerand - with balanced flue operation - in the fluegas system cools down so far, that it dropsbelow the dew point. This condenses a part ofthe water vapour created as part of the gascombustion. Contrary to low temperature boilers, the condensing energy is transferredto the heating system, enabling efficiencies inexcess of 100 % to be achieved.

A very flat cylindrical aluminium boiler body islet into the cylinder lid. The combustion chamber is arranged in the centre. The fluegas is swirled around the combustion chamberand then channelled through the top.

Any condensate created by this process is collected at the lowest point of the boiler bodyand channelled, via a plastic pipe, into thecylinder, where it is neutralised. From there it is routed via the cylinder overflow into the drain.

At the GSU, a further heat exchanger is connected via a flange in the lower part of theboiler. It is arranged inside a tubular thermalinsulation sleeve, that is open at the bottom.This heat exchanger can, when solar energy isbeing utilised, transfer solar energy to theheating network, subject to there being sufficient solar irradiation. This enables theeffective solar backup of this heating system,particularly during spring and autumn.

The ROTEX GasSolarUnit/GasCompactUnit hasbeen designed so that it can operate in balanced flue mode. In that case, the requiredcombustion air is drawn by the burner from theoutside through the installation duct or a concentric flue.

That has many benefits:- The installation room requires no ventilation

aperture to the outside and therefore does not cool down.

- Low energy consumption.- Dust, solvents, washing powders etc. are not

drawn in by the burner. The room can be used as laundry room, workshop and similar.

- The system may be installed as attic heating centre.

- Additional energy yield in the flue through preheating the combustion air.

The GSU/GCU is managed by a fully electronicdigital control unit in conjunction with the“intelligent” burner control unit. The multi-language plain text display and the key padare clearly integrated into the upper part of theGSU/GCU. This enables the checking of alloperating parameters, which may also be modified by your heating contractor. The integral control unit offers many easy, convenient operating options.

[ 5 ]

C h a p t e r 2 : G e n e r a l f u n c t i o n a n d c o m p o n e n t d e s c r i p t i o n

The safety of the GSU/GCU too is managed bythe control unit. A safety shutdown will, forexample, be implemented when there is ashortage of water, gas or in case of other, notyet defined operating conditions. Simultaneously, a corresponding fault message will be displayed, that will tell yourcontractor everything he needs to know tocarry out respective remedial/maintenancework.

The DHW is indirectly heated via the unpressurised cylinder water in a corrugatedstainless steel pipe heat exchanger. Thisstores approx. 24 litres DHW at the temperature of the DHW zone. If more DHW isdrawn, that water will be heated according tothe instantaneous water heater principle. Thishas already been proven as a perfect solutionin the DHW cylinder ROTEX Sanicube for morethan 20 years. Excellent corrosion resistance,low susceptibility to scaling and, most of all,optimum water hygiene are the hallmarks ofthis heating principle.

Extensive research by the Hygiene-Instituts ofthe university Tübingen have shown that thisprinciple is far superior to every other kind ofconventional pressurised cylinder. Particularlyin conjunction with the utilisation of solarenergy, this excellent water hygiene offersadditional assurance against bacterial growthin the hot water.

Details regarding the technical layout andfunctional backgrounds are described in detailin chapter 5.

[ 6 ]

Fig. 2.1.1: Schematic layout of the GasSolarUnit (GSU)

Pos./description

A Gas fired condensing boilerB DHW stratification cylinderC Unpressurised cylinder water D DHW zoneE Solar zoneF Heating backup zoneG Control and pump unit RPS (Solaris accessories)

1 Cold water connection (1” male) with gravity brake2 Hot water connection (1” male) with gravity brake3 DHW primary exchanger; flow connection 4 DHW primary exchanger; return connection5 Heating flow connection (1“ female)

with gravity brake6 Heating return connection (1“ female)7 Solaris flow connection (1” union nut) for GSU;

cylinder fill connection for GCU8 Solaris return connection (Tr 32x3 male)

with valve insert9 Connection for balancing line (Tr 32x3 male)

with valve insert10 Flue outlet (DN 80)11 Ventilation air connection (DN 125)12 Sensor well for DHW cylinder sensor13 Sensor well for Solaris return temperature sensor14 Condensate safety overflow connection

(Tr 32x3 male)14 a Upper fill connection (alternative: condensate

safety overflow connection, to the front - Tr 32x3 male)

15 Condensate drain hose (on site)16 Condensate pipe17 Heating heat exchanger (boiler body)18 DHW heat exchanger (DHW HE)19 Heat exchanger for cylinder heating (CH HE)20 Heat exchanger for solar central heating backup

(HB HE)21 Thermal insulation sleeve for HB HE22 Solaris flow stratification pipe23 Heating circulation pump24 Modulating pressure-jet gas burner

(see chapter 5)25 Three-way diverter valve26 Flow temperature sensor 27 Return temperature sensor28 Flue gas temperature sensor29 Safety valve

Blow-off line connection (3/4“ female) 30 Optional connection for a diaphragm

expansion vessel (3/4“ male)42 Electronic level probe

Safety equipment

Tab. 2.1.1: Part of the GSU/GCU

[ 7 ]

Fig. 2.1.2: Schematic layout of the GasCompactUnit (GCU)

[ 8 ]

Fig. 2.2.1: Part of the GSU/GCU

2.2 Component description

Pos./description

1 Cold water connection (1” male) with gravity brake

2 Hot water connection (1” male) with gravity brake

3 DHW primary exchanger; flow connection 4 DHW primary exchanger;

return connection5 Heating flow connection (1“ female)

with gravity brake6 Heating return connection (1“ female)7 Solaris flow connection (1” union nut)

for GSU; cylinder fill connection for GCU8 Solaris return connection (Tr 32x3 male)

with valve insert9 Connection for balancing line

(Tr 32x3 male) with valve insert10 Flue outlet (DN 80)

11 Ventilation air connection (DN 125)12 Sensor well for DHW cylinder sensor13 Sensor well for Solaris return

temperature sensor14 Condensate safety overflow connection

(Tr 32x3 male)14aUpper fill connection (alternative:

condensate safety overflow connection, to the front - Tr 32x3 male)

23 Heating circulation pump24 Modulating pressure-jet gas

burner (see chapter 5)25 Three-way diverter valve26 Flow temperature sensor 27 Return temperature sensor 28 Flue gas temperature sensor29 Safety valve

Blow-off line connection (3/4“ female)

30 Optional connection for a diaphragm expansion vessel (3/4“ male)

31 Boiler control panel (see chapter 4)32 ROTEX THETA 23R control unit

(see separate ROTEX control unit manual)33 Heating pressure gauge34 Silencer hood35 Locking screws for silencer hood36 Air supply hose37 Boiler fill & drain valve for filling

the heating system (1/2“ male)38 Automatic air vent valve39 Ball shut-off valve40 Thermal insulation shell

for the boiler body41 Type plate42 Electronic level probe

Safety equipment

Tab. 2.2.1: Part of the GSU/GCU

[ 9 ]

The following provides an explanation of theindividual components in line with the number-ing in Fig. 2.1.1, 2.1.2 and 2.2.1. (The safetycomponents are identified with ):

Pos. 1: Cold water inletFor the connection, observe the safety regulations in accordance with EN 806 andDIN 1988 [or local regulations]. The connecting pressure should not exceed 6bar and must, under no circumstances, behigher than 10 bar. Where required, install apressure reducer. If a DHW circulation line isrequired, install that immediately above thecold water connection (fit a non-return valve,see Fig. 5.3.1).

Pos. 2: Hot water outletWhere operating temperatures can exceed 60 °C, install an anti-scalding protection (e.g. DHW mixer installation) (see Fig. 5.3.1).

Pos. 3, 4: DHW primary exchangerThe heat exchanger for heating the DHW(DHW HE - pos. 19) is factory fitted and connected. It receives its flow from the top tothe bottom to create a countercurrent for thehighest possible DHW output.

Pos. 5, 6, 39: Heating flow (5) and return(6) with shut-off valves (39).During operation, the shut-off valves (pos. 39)must remain open (handle turned in line withthe pipe run).Shut them only to carry out work on the system (handle turned 90° to the pipe run).

Pos. 7, 8: Solar flow (7) and return (8)For the optional connection of a ROTEX Solarissystem (only GSU) for solar DHW heating andcentral heating backup. Observe the separateROTEX Solaris manual.

Pos. 9: Balance lineFor the optional connection of a ROTEX Solarissystem (only GSU) with cylinder extension orcascade control. Observe the separate ROTEX Solaris manual.

Pos. 10, 11: Flue gas (10) and ventilationair (11)For the connection of a concentric balancedflue pipe — see chapter 3.

Pos. 12: Sensor well for DHW cylindersensorThe sensor well (internal diameter 16 mm) isfactory-fitted with the cylinder sensor for theboiler control. When connecting a Solaris system, fit the associated cylinder sensor here.Please note the depth of immersion. Use onlysensors with bias spring. Observe the separateROTEX Solaris manual.

Pos. 13: Sensor well for Solaris returntemperature sensorAt this point, the cylinder temperature of thesolar zone in the inlet area of the solar circuitis measured. Observe the separate ROTEXSolaris manual.

Pos. 14, 14a and 15: Condensate safetyoverflow (14) and condensate drain (15)Drain for removing the condensate createdduring the combustion (condensing operation)— connection either at the back (14) or at thefront (14 a). The operation must proceed without faults. Route the condensate drainhose (on-site provision) with a constant slopeto the drainage system. Check the condensatedrain annually for contamination and unrestricted flow. During operation, the cylinder (pos. B) mustconstantly be filled with water (or condensate). The unpressurised cylinder canbe filled via the hose ferrule supplied and a fillhose.

Pos. 16: Condensate pipe Any condensate created in the condensingboiler and the flue pipe is routed via the condensate pipe into the cylinder, where it isneutralised and then drained away via the condensate overflow (pos. 14 or 14 a) and thecondensate drain (pos. 15) into the drainagesystem.

Pos. 17: Boiler bodyHeat released through the combustion is trans-ferred inside the aluminium boiler body fromthe flue gas to the heating water.

Pos. 18: DHW heat exchanger (DHW HE)In the DHW HE, the DHW is heated to itsselected temperature according to the instantaneous water heater principle. Thereplenishing cold water is initially routed tothe bottom of the cylinder to cool down thesolar zone (pos. E) as far as possible. On itsspiral path upwards, the DHW continuouslyabsorbs the heat of the unpressurised cylinderwater (pos. C), resulting in a distinct temperature stratification inside the cylinder.

Pos. 19: Heat exchanger for cylinder heating (CH HE)For heating up the DHW zone — see also pos.3 and 4. With the GSU, the SL HW ends approx. 40 cmabove the cylinder floor. Only the DHW zoneabove will be heated by the boiler. The cylinder volume below that point will only beheated in solar applications.With the GCU, the SL HW is drawn right downto the cylinder floor. That ensures that theentire cylinder volume is heated by the boiler,ensuring a higher DHW standby volume.

Pos. 20: Heat exchanger for solar centralheating backup (HB HE) – only GSUThe HB HE is fitted via a flange at the bottomof the boiler body. It is constantly suppliedfrom the heating return. If the temperature inthe solar zone (pos. E) is higher than that ofthe heating return, the latter will be heated bythe former. A gravity flow is created in theheating backup zone (pos. F) that enables acontinuous heat transfer.

Pos. 21: Thermal insulation sleeve for HB HE – only GSUFor the thermal separation of the heatingbackup zone (pos. F) and the DHW zone (pos. D). This prevent the cooling down of the DHW zone.

Pos. 22: Solaris flow — stratification pipe – only GSUThe stratification pipe routes the unpressurised cylinder water heated up by thecollectors with low impulses into the cylinder.This ensures that it flows to the precise levelinside the cylinder matching the solar flowtemperature. The temperature stratificationinside the cylinder remains intact.

Pos. 23: Heating circulation pumpCirculation pump for heating operation andcylinder heating. The screw cap on the automatic air vent valve (pos. 38) must remainopen.

Pos. 24: Modulating gas burner Ask a contractor to carry out a service/cleaning of the gas burner annually. Such work must only be carried out by qualified personnel. For a description, see page 5.1.

Pos. 25: Three-way diverter valveThe three-way diverter valve changes overbetween heating mode and cylinder heating. When filling the heating system for the firsttime, lock the three-way diverter valve in itscentral position. For this, ensure the powersupply cable is pulled off (standard deliverycondition) or pull it (Fig. 2.2.2). Plug it back intothe servomotor no sooner than one hour aftercommissioning.

Note: The central position remains stable only when the valve is at zero volt. The valve resets itself

automatically when the servomotor is supplied with power to drive into the valvepositions AB-A (cylinder heating).

1 Boiler return2 Heating return3 Cylinder heating return4 Three-way diverter valve5.1 Valve servomotor5.2 Reset button of the servomotor lock5.3 Lever

Pos. 26, 27: Flow (26) and return (27); temperature sensor The sensors (type NTC) are screwed into thewaterways of the boiler body. The sensorleads can be plugged in. The sensors aredirectly connected to the gas burner controlunit. This also safeguards the low water indicator and high limit safety cut-out functions.

Pos. 28: Flue gas temperature sensor The sensor (type Pt 1000) is screwed into theflue gas channel of the boiler body immediately upstream of the flue outlet. Thesensor lead can be plugged in. The control unitfulfils a limiter function and shuts the burnerdown if the flue gas temperature is everexceeded. A maintenance message will alsobe generated, if the flue gas temperatureexceeds the typical maximum boiler values.

Pos. 29: Safety valve The GSU/GCU is equipped with a safety valve(3.0 bar). Connect a permanently open blow-off line without restrictions to its internaldiameter in accordance with EN 12828, toensure that the safety valve can always andcorrectly function (the outlet must be unrestricted and must be visible).

Pos. 30: Diaphragm expansion vessel -connection At this point or somewhere else in the heatingsystem, connect a diaphragm expansion vesselto EN 13831 via a permanently open line inaccordance with EN 12828 and DIN 4807.

Pos. 31: Boiler control panel Central user interface for the display andadjustment of operating parameters; see theseparate description (chapter 4).Comprises the control electronics and all electrical connections.

[ 10 ]

Fig. 2.2.2: Fill position of the three-way diverter valve

Pos.32: ROTEX 23R control unitThe control unit operation and functions aredetailed in the separate ROTEX control unitmanual.

Pos. 33: Heating pressure gauge Pressure gauge for regulating the system pressure. The pressure must me indicated inthe green range of the display (generallybetween 1.5 and 2.5 bar). Top up with waterwhen the system pressure is too low (for adescription, see pos. 37).

Pos. 34, 35: Silencer hood The hood should always be fitted during operation. It is secured with two screws (pos.35) on the l.h. and r.h. side of the cylinder lid.Clean with luke-warm water, solvent-freedomestic cleaning agent and a soft cloth.Never use scouring agents or solvents.Remove only for maintenance work (chapter 6).

Pos.36: Air supply hoseCombustion air from the annular gap of theconcentric balanced flue pipe is channelled tothe burner via the air supply hose.

Pos. 37: Boiler fill & drain valve for fillingand drainingTopping up the heating system (if the systempressure is too low): Connect the filling hoseand top up the system, until the pressuregauge indicates in the upper part of the greenrange (generally 2.0 to 2.5 bar).

Pos. 38: Automatic air vent valveOpen the screw cap to vent the GSU/GCU. This air vent valve is generally insufficient tovent the entire heating system.

Pos. 39: Ball shut-off valveDuring operation, the shut-off valves mustremain open (handle turned in line with thepipe run).Shut them only to carry out work on the system (handle turned 90° to the pipe run).

Pos. 40: Thermal insulation shell for theboiler bodyTo minimise the radiation and standby lossesof the GSU/GCU. For removal, first remove theburner and all connection lines.

Pos. 41: Type plateShows the most important performance detailsand parameters of the GSU/GCU as well asthe serial number of the equipment, thatshould always be quoted when referring anyquestions to ROTEX.

Pos. 42: Electronic level probeThe cylinder fill level is monitored via the threeelectrodes of the level probe and indicated bycontrol indicators on the user interface. Theburner will be locked out if the level in thecylinder is too low.

[ 11 ]

[ 12 ]

C h a p t e r 3 : P o s i t i o n i n g a n d i n s t a l l a t i o n

Installation version 5.The boiler is located immediately under theroof. The combustion air and flue gas arerouted through a concentric twin pipe. Flue gasis expelled to atmosphere through the innerpipe; combustion air is drawn in through theouter annular gap. The distance between theflue gas outlet and the roof area must be atleast 40 cm. Connection with set L (see Fig.3.4.3).

Installation version 6.Like installation version 2, but the balancedflue pipe is routed through the roof structure.In this area, the balanced flue pipe must berouted through a protective pipe with sufficient fire resistance; alternatively it mustbe physically separated from the roof structure.

The ROTEX GasSolarUnit/GasCompactUnit canalso be installed for open flue operation. Inthat case, only the inner flue (plastic connection Ø 80 mm) of the concentric balanced flue connection is joined to the fluepipe. In his case, the boiler will draw in combustion air from the installation roomthrough the annular gap of the sleeve pipe. Note: With this version, the installation roommust provide a ventilation aperture of at least150 cm2 unrestricted cross-section.

Information regarding the installation in garages

The ROTEX GasSolarUnit/GasCompactUnit isgenerally suitable for installation and operation in a garage, subject the the following conditions being met:- Balanced flue operation in accordance

with the above installation versions- Fitting a permanent version of the operating

instructions at an easily accessible point near the boiler

- On-site creation of a protective measure against mechanical damage (from vehicles, for example) - e.g. bull bars or deflectors - for the whole system.

3.2 Installation options

Generally, a balanced flue connection isrequired for the ROTEX GasSolarUnit/Gas-CompactUnit. A concentric balanced flue DN 80/125 certified for condensing operationis available (DIBT - certificate Z-7.2-1051, Z-7.2-3061, Z-7.2-3062).

The GSU/GCU can be installed in 4 differentways (see Fig. 3.2.2).

Installation version 1.The chimney or service duct delivery the combustion air from outside. The flue gas isrouted through the same duct in a certifiedflue (ø 80 mm) to above the roof and to atmosphere. The distance between the fluegas outlet and the roof ridge must be at least40 cm. The boiler is connected with the balanced flue pipe set H or K (see Fig. 3.4.1 to3.4.3).

Installation version 4.The boiler is connected with the set H or K(see Fig. 3.4.1 to 3.4.3) to the external wall setG.This concentric pipe is routed through theexternal wall to the outside and then at least40 cm above the roof. For the external part, theouter air gab acts as thermal insulation for theflue pipe. The combustion air is drawn fromthe outside via the annular gap of the concentric twin pipe.

If the wall outlet is less than 1 m above groundlevel it is recommended to supply the combustion air through a ventilation pipe at aheight of at least 2 m. (PPW-ZR, part no. 15 50 79.00 66).

3.1 Delivery

Caution: Risk of tippingIn their delivered condition, ROTEX GasSolarUnit/Gas-

CompactUnits are top-heavy. Tipping overcan result in risks to individuals and damage to the equipment. Handle withcare.

The ROTEX GasSolarUnit/GasCompactUnit isdelivered on a pallet. Any level transport aids,such as a pallet truck or forklift truck, are suitable for transporting the unit. The standarddelivery of the GSU/GCU comprises the factory-fitted circulation pump, the three-waydiverter valve and the safety equipment. Allconnections are in easy reach.

[ 13 ]

Fig. 3.4.3 shows the most important standardassemblies.

The design prevents higher temperatures than80 °C at any component outside the boiler casing during operation at the rated output.Consequently, no specific minimum distance tocomponents made from combustible materialsmust be maintained. However, in general noeasily flammable or ignitable materials shouldbe stored or used in the immediate vicinity ofthe boiler — maintain an adequate distance.

Table 3.2.1 summarises the maximum permissible flue heights for those cases,where the GSU/GCU is operated in the ratedoutput range.A specific calculation can be made for thosecases, where the output range is limited forcertain reasons. The system flue gas volumeflow is subject to the selected burner output,as shown in Fig. 3.2.1 and in Table 9.1. Forparameters relating to the flue gas calculation,see chapter 9.

Note: If more than 3 diversions in excess of45° are required in the flue, the maximumheight reduces by 1 m per diversion - it may benecessary to carry out a flue gas calculation. The maximum height will also be reduced ifthe horizontal connecting piece must beextended. It is reduced by the length, by whichthe connecting piece is extended.

General information regarding the flue gas system

Regarding the layout and sizing of the flue gas system, reference is made to the respectively applicable

fire prevention regulations and DIN 18160[or local regulations]. Generally speaking, the system can beconnected to any flue with Building Regulation approval, subject to the follow-ing conditions (leaning on DIN 18160-1)being met:• suitable for at least 120 °C

(temperature class T 120 or higher)• withstands at least 200 Pa positive

pressure (pressure class P1 or H1)

• moisture-resistant (condensate resistance class W)

• adequate corrosion resistance (corrosion resistance class 1 or 2)

These properties of the flue gas systemmust be identifiable at the installed system. For this purpose, a type plateappertaining the flue must be fitted in theinstallation room.

• We strongly recommend the use of theROTEX flue gas sets, as these are fittedwith particularly acid-resistant gaskets.

The maximum permissible flue gas backpressure is 200 Pa. The pressure drop inthe air supply line must not exceed 50 Pa.

Where possible, the angle of introductionof the flue into the chimney should beapprox. 3°. Implement horizontal sectionsof the flue pipe with an incline of approx. 3°. Nowhere along the length ofthe flue must a counter-slope occur.

Maximum permissible effective height of the flue pipe in metres:Installation version GSU 25, GCU 25/DN 80 GSU 35, GCU 35/DN 80

1 1) 22 224 2) 15 185 2) 20 226 2) 20 22

1) Duct cross section with DN 80: 135 mm x 135 mm2) Concentric balanced flue DN 80/125Table 3.2.1: Max. effective height of the flue pipe

Fig. 3.2.1: Flue gas mass flow/burner output ROTEX GasSolarUnit

F l u e g a s r o u t i n g

[ 14 ]

Fig. 3.2.2: Installation versions for the ROTEX GasSolarUnit/GasCompactUnit

* linear ventilated duct with a 90 min fire resistance, for low domestic buildings 30 min fire resistance

Air

❷ Flue gas

[ 15 ]

3.3 Positioning

Caution: Insufficient load bearing capacity of the floor can lead to damage to the

floor structure, the equipment and to risksto individuals. Ensure that the floor has a minimum load bearing capacity of 1050 kg/m2 plus an appropriate safety margin.

Caution: Risk of tippingThe GasSolarUnit is top-heavy in its delivered condition. A

falling unit can easily be damaged andinjure an individual. Move the equipmentcarefully with a hand truck or carry it at itshandles, whilst stabilising its position.Secure the equipment particularly whenmoving the equipment up or down stairs.

After removing the packaging, the ROTEX GasSolarUnit/GasCompactUnit can beinstalled at the intended site. The surfacewhere the system is to be installed must besolid, level and horizontal. Where necessary,install a suitable plinth. Route all connectingcables/leads so that the silencer hood (Fig.2.2.1, pos. 34) can be removed).

The GSU/GCU flue can be connected in threedifferent ways. Standard connection is the direct flue connection out the back (Fig. 3.3.1 - set H:PPD-H, part no. 15 50 79.08). If there is a chimney adjacent to the GSU/GCU, then the side flue outlet can be used (Fig. 3.3.2 - set K: PPD-K, part no. 15 50 79.09). A flue connection with direct roof outlet is alsopossible (set L: PPD-L, part no. 15 50 79.10). For further details and connection dimensionsfor the three flue connection options, seechapter 3.4 section “Connection of the flueand ventilation air line”.

Fig. 3.3.1 and 3.3.2 show the installation anddistance dimensions.

Fig. 3.3.1: Installation dimensions for flue connection out the back

Fig. 3.3.2: Installation dimensions for flue connection at the side

S e t s o f b a l a n c e d f l u e l i n e s

[ 16 ]

Flue outlet straight out of the back

For the standard connection, especially out theback, we recommend the balanced flue connections set H that is specifically tailoredfor the ROTEX GasSolarUnit/GasCompactUnit.For the components and layout of this set, see Fig. 3.4.1):

Balanced flue connection set H: part no. 15 50 79.08

1 PP balanced flue elbow 87° DN 80/1252 PP balanced flue test

port piece DN 80/1253 PP balanced flue

inspection pipe DN 80/1254 Cover plates, white DN 1255 PP balanced flue wall outlet DN 80/125

Flue outlet out of the side and back

We recommend the flue connection at theside, if the ROTEX GasSolarUnit/Gas-CompactUnit cannot be connected out theback. The side flue connections can beachieved with the balanced flue connectionset K. Components and layout for connectionout the side to the back as follows (see Fig. 3.4.2):

Balanced flue connection set K: part no. 15 50 79.09

1 PP balanced flue elbow 87° DN 80/1252 PP balanced flue test

port piece DN 80/1253 PP balanced flue inspection

bend 87° DN 80/1254 Cover plates, white DN 1255 PP balanced flue wall outlet DN 80/1256 PP balanced flue pipe

(PPD L50) DN 80/125

Fig. 3.4.2: Flue connection out the side with the balanced flue connection set K (top view)Fig. 3.4.1: Flue connection to the back with thebalanced flue connection set H (top view)

3.4 Connecting the GasSolarUnit

Connection of the flue gas and ventilation air lines

General: The installer must agree the requiredwork with the relevant flue gas inspector[where appropriate]. Even in regions wherethis is not legally required, we recommend theinvolvement of the flue gas inspector, who canbe notified with a standard form.

The ROTEX GasSolarUnit/GasCompactUnitmust be connected to the flue gas system onthe same floor as where it is installed.The balanced flue boiler connection has adiameter of 125 mm (ventilation air) and 80 mm (flue gas), and is fitted with speciallyacid-resistant gaskets. Generally speaking, theboiler can be connected to any flue certifiedfor condensing operation.(system with valid DIBT certificate — see general information in chap. 3.2)

Note: A flue gas high limit safety cut-out is not required on site due to the intentionally low flue gas

temperatures!

[ 17 ]

Fig. 3.4.3: Flue gas system sets

[ 18 ]

B a l a n c e df l u e c o n n e c t i o n

G a s a n d w a t e r c o n n e c t i o n

Flue with roof outlet

Frequently, attic heating centres are connectedto a direct flue outlet through the roof. Forrouting flue gas through the roof, ROTEX offersthe balanced flue system connection set L.Components and layout of this set as follows(see Fig. 3.4.3):

Balanced flue connection set L: part no. 15 50 79.10

1 PP balanced flue test port piece DN 80/125

2 PP balanced flue inspection pipe DN 80/125

3 Roof outlet 400 mm DN 80/125above the roof, incl. batten clip, black

Important: Generally order a matching roof cover for sloping or flat roofs separately to the set L.

Supplementary assemblies

For the flue connections to a duct or an external wall system, ROTEX offers supplementary flue gas system sets with allrequired components (for duct flue set E, forexternal wall flue set G). In case of higher ceilings or roofs, use additional PP balancedflue pipes. Use additional single wall PP pipesfor chimney heights above 10 m. For individualprices, see the ROTEX pricelist.

Note: Vibrations in the flue gas system can, in some cases, result in an outlet noise at the flue outlet

that some find a nuisance. The noise levelcan be effectively reduced with the outletsilencer, available under part no. 15 45 78.

Heating and DHW line connection

All connection lines of the GSU/GCU leadupwards through the cover hood. Only the connection of the return of the optional ROTEXSolaris system is located at the equipmentfront. The heating circuit and the cylinder primary circuit share a common flow andreturn. The cylinder primary circuit is integrated at the factory and does not requirea separate connection.

Important: If the GSU/GCU is connected to an existing heating system with pipework or radiators

made from steel or with permeable underfloor heating system pipes, flush theheating network before connecting theheating lines.Fit a dirt filter into the heating return toprotect the heating circuit pump.

When connecting the equipment to the coldwater supply, ensure that the maximum mainspressure should be around 6 bar. Never exceed10 bar. Install a pressure reducer if highermains pressure prevails. For connection work,EN 806 and DIN 1988 [or local regulations]apply.

The heating connections are fitted with femalethreads, those for DHW with male threads.Position and dimension can be found in Fig.3.4.4.

Please note: Risk of corrosionIf steel pipes are used in the cold water supply line, there

will generally be a risk that swarf canenter the corrugated stainless steel pipeheat exchanger, where it could settle. Thiscase must be prevented by using a filter orby flushing the feed line prior to filling theheat exchanger. Otherwise corrosiondamage and heat exchanger leaks couldresult.

DHW cylinders should be installed as closelyas possible to the draw-off points. A DHW circulation line is frequently not required, evenif draw-off points are further away.Where a DHW circulation line is a must, thiscan be implemented in accordance with thediagram in chapter 5.3. To minimise heatlosses, carefully insulate (thermally) the entireDHW pipework. Any scale that may be createdas a result of heating the water, will beflushed out with the DHW of the corrugatedstainless steel pipe heat exchanger.

Please note: Where water is very hard (harder than’ ~ 1.8 mmol/l), it is recommended

to install a filter in the DHW line. Otherwise there might be a risk that theflushed-out scale can block the perlatorsin the taps.

Make the connection of the blow-off line tothe safety valve and the diaphragm expansionvessel connection in accordance with EN 12828.

Please note: Danger risk of scalding!As cylinder temperatures in

excess of 60 °C can occur, particularlywhen operating the GSU with a solar heating system, install an anti-scaldingdevice on site (DHW mixing facility). Thesame applies to the GCU, if set DHW inexcess of 60 °C have been selected orpasteurisation has been activated.

Low water indicator

The ROTEX GasSolarUnit/GasCompactUnit hasbeen verified in tests to safely shut down andinterlock the burner in case of water shortagethrough the overheating protection. Thismakes an on-site low water indicator superfluous.

Connection of the gas supply pipe —checking the gas type and burner settings

Warning: Risk of explosion Incorrect handling of gas equipment can lead to gas

explosions: Danger to life Only authorisedgas fitters are allowed to work on gasequipment.

The gas connection must meet the technicalrules for gas installations in accordance withcurrent regulations of the gas supply companyand the relevant country of installation. At theequipment, the gas supply pipe is connected tothe type-tested corrugated gas hose (pipethread DIN 2999 - Rp 1/2“) (Fig. 3.4.5).

static gas inlet pressure (Fig. 3.4.6) and compare it with the values listed in Tab. 3.4.1.The standard gas supply hose can cause apressure drop of approx. 5 mbar. The supplypressure at the gas valve can therefore bebelow the value in the table by that amount.This will not have a negative influence on theequipment function.

1) Notify your gas supply company if the gassupply pressure falls outside the stated range.2) Where the rated pressures deviate, observethe limits in accordance with the regulationsof the relevant country.

Tab. 3.4.1: Gas supply pressure

The connection hose is factory-fitted, so thatthe burner can be removed for maintenancework, without needing to be disconnectedfrom the gas mains.

Install a thermally activated shut-off valve(TAE) and a gas flow limiter (GSW) with DVGWtest symbol [check local regulations] on site.The TAE must comply with the test standardaccording to DVGW-VP 301 [or local regula-tions]. Size the GSW in accordance with themaximum selectable rated load of the equip-ment. The gas type must be identical to that statedon the yellow label on the burner fan. If theburner is not identified as being suitable forthe available gas type, convert the burner tothe available gas type and mark it accordingly(see chapter 5.1). Test the

[ 19 ]

Fig. 3.4.4: Connection dimensions for the heating and DHW connection (top view)

Fig. 3.4.5: Gas connection

1 Cold water (pipe thread 1“ male)2 DHW (pipe thread 1“ male)5 Heating flow (pipe thread 1“ female)6 Heating return (pipe thread 1“ female)

30 Diaphragm expansion vessel (pipe thread 3/4“ male)

7 Solaris flow (pipe thread flatpacking 1“ union nut)

29 Safety blow- (pipe thread 3/4“off line female)

37 Boiler fill & drain valve (pipe thread 1/2“ male)

Gas type Inlet pressure in mbar 1)

Rated min max.pressure

Natural gas E, H 20 17.0 25.0Natural gas LL 20 17.0 25.0LPG 2) 50 42.5 57.5

Fig. 3.4.6: Checking gas inlet pressure

back

front

C o n d e n s a t e / s e n s o r c o n n e c t i o n

[ 20 ]

Connection, condensate drain

The condensate created when the hot gassesinside the boiler and flue gas system cooldown is routed via the condensate pipe intothe cylinder. There it is neutralised and thendrained off via the safety overflow (Fig. 3.4.7)into the drainage system.

For this, route the condensate drain hose (notpart of the standard delivery) with a constantslope towards the drainage gully. Route thecondensate drain freely into the drainage system.

The drain outlet must be permanently openand must route the medium, in case of a fault(DHW, buffer or heating water), visibly andsafely outside (in accordance with DIN 4743 T.11 [or local regulations]) (e.g. hose connectionat the drain gully or transparent drain hose).

Connection of the electricalcables/leads

Warning: Electric shocks can cause severe burns and life-threatening injuries.

Modifications to the electrical installationare dangerous and are therefore not permitted. The power connection mustonly be carried out by an authorised electrician, who must observe all localand national regulations, as well as thosespecified by the local electricity supplycompany.

The ROTEX GasSolarUnit/GasCompactUnit isdesigned for connection to a 230 Volt, 50 HzAC supply. Prior to connecting the ROTEX GasSolarUnit/GasCompactUnit ensure that thesupply voltage is that stated on the type plate.

To prevent an interchange between the mainsand the sensor connections, both are identifiedwith different colours and forms on the plug-inPCB of the boiler control panel (Fig. 3.4.8 and3.4.9).

The ROTEX GasSolar-Unit/GasCompactUnithas already been fully wired at the factory. Athree meter long flexible power supply cableand the outside sensor lead have already beenterminated inside the equipment and areplugged into the connection PCB of the controlpanel. Connect then via distribution panels tothe domestic installation.Only optional equipment needs to be connected to the boiler (mixer circuit, DHW circulation pump etc.).

Note: Ensure the correct termination of phases. If the polarity is incorrect, the ON/OFF

switch will remain illuminated even after ithas been switched off.

Fig. 3.4.7: Safety overflow and condensate drain

Fig. 3.4.8: Location of the PCB plugs

[ 21 ]

Temperature sensor connection

The boiler is equipped with a weather-compensated control of the flow temperature.This function requires the connection of anoutside temperature sensor. The DHW temperature sensor (cylinder sensor) requiredfor the operation of the integral DHW cylinderis fitted and terminated (PTC resistor) in thefactory.

Fit the outside temperature sensor at a heightrepresenting approx. one third of the buildingheight (minimum distance from the ground: 2 m) on the coldest side of the building (northor north-eastern side). Never mount the sensornear external heat sources, otherwise the temperature it captures could be falsified(chimneys, hot air from air ducts, sunlight etc.).The cable outlet must always point down-wards to prevent the ingress of moisture.

For the electrical installation, a 2-core cablewith a minimum cross-section of 1 mm2 is recommended. The outside temperature sensor resistance is 2000 Ω at 25 °C (PTCresistor).

The internal temperature sensors are fullywired up at the factory. The flow and returntemperature sensors (NTC resistors) are connected together with the control cable forthe burner fan via a common plug at the burnercontrol unit CVBC of the pressure-jet burner.The flue gas temperature sensor (Pt resistor) isconnected directly at the control panel. Thetemperature sensors can be directly plugged inat the individual sensors to ease replacement.

To regulate a mixer circuit, connect a mixer circuit flow sensor (accessories TMKF, part no: 15 60 62) (PTC resistor).

Fig. 3.4.9: Connection allocation of the PCB plug and cable/lead colours of the factory-fitted connecting cable

Important: Generally, route the sensor leads outside the equipment separately. Never

route sensor leads and mains powercables inside the same conduit. This couldlad to severe faults in the control operation. To safeguard the perfect operation and toprevent damage to the control unit, useonly the original ROTEX sensors supplied. The outside temperature sensor and allinternal temperature sensors are part ofthe standard delivery. To operate the system without the DHWcylinder (the cylinder must, nevertheless,be filled!), remove the sensor prior tocommissioning from the PCB plug. Connecting the mixer assembly AMK1(part no. 15 60 44) requires the mixer circuit contact sensor TMKF (part no. 15 60 62). Observe the operating instructions for the ROTEX control unit.

* when using a DHW primary pump cable

[ 22 ]

Pumps, three-way diverter valve

The GSU/GCU are equipped with an integralcirculation pump and a three-way divertervalve (3W-UV) as standard. Both pump and thethree-way diverter valve are equipped with acable and plug each. These cables are fullywired and can be plugged in at the controlpanel and at the pump/valve servomotor.


Fig. 03.04.10: Three-way diverter valve

The valve is mounted so that connection B isconnected on the heating side and A on thecylinder side. Observe chapter. 5 when fillingthe system.

Optional connection options

Mixer circuit connection

The GSU/GCU are equipped as standard, sothat a mixer circuit, that is regulated by theelectronic boiler control unit, can be connecteddirectly to the boiler. For this, ROTEX offers afully wired mixer assembly AMK1 (part no. 15 60 44), what comprises an integral circulation pump, a motorised mixer and shut-off valves with temperature displays in aninsulating enclosure. With the mixer circuitcontact sensor TMKF (part no. 15 60 62), themixer assembly can be connected directly tothe PCB connections (fully wired PCB plugs onthe GSU/GCU).

An additional mixer circuit and/or cylinder primary circuit can be regulated by the heatingcircuit extension module THETA HEM1 (partno. 15 60 61). The heating circuit extensionmodule THETA HEM1 communicates via theBUS with the central controller in theGSU/GCU. Cascading the THETA HEM1enables the system to be extended to up tofive mixer circuits and/or cylinder primary circuits. Order the temperature sensorsrequired in connection with a heating circuitextension module separately. (mixer circuitcontact sensor TMKF: part no: 15 60 62, cylinder temperature sensor TSF: part no: 15 60 63)

Room thermostat connection

A separate room controller THETA RFF (part no. 15 40 70) can be connected for every heat-ing circuit. This enables the operating modeand the set room temperature (see operatinginstructions ROTEX control unit) to be modifiedfrom the room, where the device is installed(remote control). Simultaneously, the heatingcircuit temperature will be matched accordingto the required room temperature (proportionalroom influence).

Room station connection

The room station THETA RS (part no. 15 70 18)allows the display and adjustment of all temperatures and operating modes of theTHETA 23 R (central control unit). Apart fromthe emissions test and manual function (seeoperating instructions ROTEX control unit), allcontrols (display, keys, rotary selector) andfunctions (e.g. switching time program) areidentical with the central control unit. TheTHETA RS can be installed in any suitablelocation inside the building, where it can function as a remote control for the GSU/GCU.Connection and communication are made viathe data bus connected to the central controlunit.

F i l l i n g t h e s y s t e m

3.5 Filling

Only fill the heating system when all installation work has been completed. Fill theROTEX GasSolarUnit/GasCompactUnit in thefollowing sequence:

1. DHW heat exchanger (always fill first)

Open the shut-off valve in the cold water inletpipe to fill the corrugated stainless steel pipeheat exchanger. Open the DHW draw-off tapsduring the filling process to adjust the highestpossible draw-off volume. Let water run for a little while after it firstemerges to fully vent the heat exchanger andto flush out any contamination or residuesfrom the water pipework. Observe the warningin chapter 3.4 section “Connection of the heating and DHW lines”.

2. Unpressurised cylinderIf a Solaris system is installed with theGSU/GCU, fill the cylinder simply with a hoseconnected to the boiler fill & drain valve on thecontrol and pump station (RPS).

If no Solaris system is connected to the GSU,fill the cylinder through the hose ferrule supplied and fitted to the upper side connection of the cylinder (pos. 14a in Fig. 2.2.1) or a hose connected to the Solarisflow connection (pos. 7 in Fig. 2.2.1).

Fill the GCU via a hose plugged into the fillingport (pos. 7 in Fig. 2.2.1) or a hose connectedto the hose ferrule supplied and fitted to theupper side connection of the cylinder.

Fill the cylinder once until water is expelledfrom the safety overflow or the condensatedrain.

Important: Fill the cylinder until is overflows to ensure that all three electrodes of the level sensor

are immersed in water. Only this ensuresthat the electronic can register the ade-quate level and enable the burner opera-tion. The burner will be locked out if the level istoo low.

3. Heating and DHW primary circuit

Lock the three-way valve in its central positionfor filling (a stable central valve position canonly be assured in a zero volt condition - factory-set condition). To ensure that the system is fully vented, do not release thethree-way diverter valve by pushing in thereset button earlier than one hour after thesystem has been started (Fig. 3.5.1).

Note: The central position remains stable only when the valve is at zero volt. The valve resets itself

automatically when the servomotor is supplied with power to drive into the valvepositions AB-A (cylinder heating).


Fig. 3.5.1: Fill position of the three-way diverter valve

The fill & drain valve (boiler fill & drain valve)is located in the pump line of the Gas-SolarUnit/GasCompactUnit (pos. 37 in Fig. 2.2.1). Connect a 1/2” hose to this valve.Open the fill & drain valve and start to fill thesystem with water, until the pressure gaugeindicates a positive system pressure in thecentre of the green range of the pressuregauge glass (pos. 33 in Fig. 2.2.1). First turnthe pressure gauge glass so that the minimumpressure indicator equals the system heightplus 2 m (1 m WS equals 0.1 bar). Ensure thatboiler water cannot flow into the DHW line. Vent the heating network after filling.

[ 23 ]

Fig. 3.6.2: High limit safety cut-out test function

3.7 Standards and guidelines

Apart from the general technical rules, observeall applicable standards and guidelines:

Standards:DIN 1298, 1988, 3388, 3440, 4702, 4743, 4753, 18160DIN EN 303, 483, 625, 677, 806, 50165.

Guidelines:TRGI ‘89 Code of Practice G 600 issue 1996, G 600-B issue Dec. 2003, G 260-I or TRF.

VDI sheets: VDI 2035, 2067, 2068, 3808

VDE sheets: VDE 0100, 0116, 9772

[ 24 ]

Current heatsource temperature

Remainingtime from activation

Cancel emissions test prematurely

Current heatsource temperature

hold down

The system is started by switching the ON/OFFswitch ON (pos. 1 in Fig. 4.1.1). After the startphase, pressing the manual key (pos. 13 in Fig.4.1.1) for longer (approx. 5 s) and by selectingthe required manual temperature at the rotaryselector (pos. 6 in Fig. 4.1.1), “Manual mode”can be adjusted (see also Fig. 3.6.1). Beforethe final commissioning, test the high limitsafety cut-out function and fine-tune the gasburner by measuring the flue gas (see chapter5.1 “Gas burner”).

Fig. 3.6.1: Manual mode

Testing the high limit safety cut-out function

Caution: Risk of burning! The boiler body will get very hot.Never touch metallic parts on

the burner or the boiler body.

Before starting the test, close the ball valve atthe heating flow connection and isolate theservomotor of the three-way diverter valve. Forthis, press the reset button on the servomotorof the valve (pos. 5.2 in Fig. 3.5.1) and turn themotor a quarter of a revolution anti-clockwise.

Briefly press the manual key (pos. 13 in Fig.4.1.1) to test the high limit safety cut-out. Thehold down the rotary selector (pos. 6 in Fig.4.1.1) until the high limit safety cut-out hasresponded. The display (pos. 14 in Fig. 4.1) display “STB test” (see Fig. 3.6.2). After a successful test, reset the high litres capacitymanually after the boiler has cooled down(open the ball valve at the heating flow connection again) by pressing the manual keybriefly again when the display shows “RESET”.

Note: Check all connections for leaks before commissioning the system. To prevent corrosion

products and sedimentation, observe therules of VDI 2035 [or local regulations].Take measures to stabilise or reduce thewater hardness if the fill and top-up wateris particularly hard. We recommend theuse of Fernox anti-scaling and anti-corrosion agent KSK (part no. 15 60 50) inaccordance with the manufacturer’sinstructions for areas suffering fromextreme water hardness.

Important: During the system operation, regularly check the water pressure at the pressure

gauge (green range) and top-up, ifrequired.

3.6 Initial start-up

The ROTEX GasSolarUnit/GasCompactUnit isread for operation after all connections havebeen made; it can then be commissioned byyour heating contractor. Carefully check theattached checklist prior to commissioning.When all questions in this checklist were ableto be answered with “Yes”, then the factory-set burner can be started temporarily.

Note: Immediately after starting thesystem, check the burner adjust-ment with a smoke gas analyser

and adjust the burner, if required (see chapter 5.1).

press for approx. 5 seconds

Set temperature

change

Return to the original operating mode, standard display, the selected set value is saved

Actual valueRequired setvalue (flashing)

[ 25 ]

Check list prior to commissioning

1. Is the combustion air supply assured? Yes No

2. Is the adequate venting of the installation room assured? (only for open flue operation) Yes No

3. Does the power supply meet all relevant regulations? Yes No

4. Is the power supply 230 Volt 50 Hz? Yes No

5. Is the balanced flue line correctly connected and sound? Yes No

6. Has the heat distribution network been flushed (in modernisation projects)? Yes No

7. Is an adequately sized diaphragm expansion vessel correctly fitted? Yes No

8. Is the safety valve connected with an open drain? Yes No

9. Is the system pressure in the green range? Yes No

10. Have the boiler and the heating system been vented? Yes No Open all control valves fully for venting and the initial start-up.

11. Is the cylinder full of water? Yes No

12. Are all sensors connected and correctly positioned? Yes No (outside temperature sensor, cylinder temperature sensor)

13. With a mixer installation (option), is the mixer circuit sensor, mixer motor and the mixer circuit pump Yes No connected to he correct plug-in position and are the corresponding plugs plugged in to the respective position on the PCB?

14. Is the room station correctly terminated (A, B) and plugged in? Yes No

15. Is the gas supply correctly connected and correctly installed? Yes No

16. Is the gas line correctly vented and sound? Yes No

17. Are the gas type and the gas inlet pressure identical with the values on the burner label? Yes No

Only start the system if you have answered “Yes” to all of the above questions.

Check list post commissioning

A Is the circulation pump running - is the heating system getting warm? Yes No

B Is the flow pressure within the range permissible for this gas type? Yes No

C Are the screws for the gas test points tight and sound? Yes No

D Has the plug of the three-way diverter valve been plugged in again after commissioning? Yes No

Only hand the system over to the system user if you have answered “Yes” to all of the above questions.Complete the installation and training form supplied together with the user.

[ 26 ]

C h a p t e r 4 : B o i l e r u s e r i n t e r f a c e

1 ON/OFF switch2 Central fault message indicator3 Legend to identify the equipment type4 Pressure gauge5 Control unit: Central control unit

THETA 23R6 Rotary selector for selection

and adjustment7 Key for the set day room temperature8 Key for the setback room temperature9 Key for the set DHW cylinder temperature

10 Operating mode selector11 Key for the setting of the automatic

time program12 Info key for system information13 Key for emissions test and manual mode14 Display (illuminated)15 Compartment for the abridged

operating instructions16 Control unit fixing screws17 Level monitoring indicator

for adequate water level18 Level warning indicator for low water level

4.1 Brief description

All important controls and electrical boiler connections are integrated into the boiler control panel. The electronics ensure the trouble-free system operation. All display andcontrol elements are identified with positionnumbers in Fig. 4.1.1; their description is givenin the following.

1 ON/OFF switch Operate the ON/OFF switch to start/stop theboiler. The ON/OFF switch illuminates greenwhen the heating system is switched ON. Ifthe heating system operates correctly, thegreen level indicator (17) will also illuminate.All other indicators will then be OFF.

2 Central fault message indicatorThe illuminator will be OFF in standard operation. There will be a fault if it illuminates(e.g. unsuccessful starting attempt, sensorbreak and similar).Characteristics in case of a fault: The user canrestart the burner after a burner fault by pressing the rest button (pos. 13) and display“<< RESET” (pos. 14). Remove the cause if theburner fault occurs repeatedly (see also chapter 5.1 “Gas burner”). Faults are generally displayed with fault code.For troubleshooting information, see chapter 7.

3 Legend to identify the equipment typeThis type immediately indicates, whether theboiler is a GasSolarUnit or a GasCompactUnitversion. Except for this legend, the boiler control panel for the GSU and the GCU areidentical.

4 Pressure gaugeThis indicates the water pressure in the heating system. During the system operation,regularly check the water pressure at the pressure gauge (pos. 4). The black needleshould be inside the green range and to theright of the red indicator (see also chapter 3.5).Top up with water if the system pressure dropsbelow the minimum pressure indicated by thered needle. Check the on-site installation if thepressure drops constantly.

5 Central control unit THETA 23RThe electronic digital control unit ROTEXTHETA 23R can regulate 2 heating circuits(direct heating circuit and mixer circuit) as wellas one cylinder primary circuit. It comprises adigital time switch with three individuallyadjustable heating programs per heating cir-cuit. As option, a DHW circulation pump canbe regulated. In addition, this control unitenables up to 5 GSU/GCU or a heating circuitextension with a heating circuit extensionmodule HEM 1 with up to four pieces of equipment to be cascaded. Furthermore, amodem can be connected for changing theoperation mode via telephone, and a burnerblocking contact (e.g. through a wood firedboiler or a solar heating system) can behooked up.

Fig. 4.1.1: Boiler control panel

[ 27 ]

11 Adjusting an automatic time programThis is designed to quickly select one of the three available time switch programs. Foradjusting the switching times, see theabridged operating instructions or the operating instructions “ROTEX control unit”.

12 System informationAfter lightly pressing the information key, allsystem temperatures and operating conditionsof all system components can be scanned inorder by means of the rotary selector (pos. 6).

13 Emissions test, manual mode, Reset functionThe manual key has 3 functions:• Emissions test for the flue gas inspector(press lightly): The boiler will be regulated tothe defaulted maximum temperature. Afterlightly pressing this key, the burner will operate at maximum output. By pressing thekey again, the burner will ramp down to itsminimum output.The three-way diverter valve will be in thecylinder heating position until the maximumpossible cylinder temperature has beenachieved. The system then switches over toheating mode (see also chapter 9).• Manual mode (hold down for 5 s): The boilerwill be regulated in accordance with theselected set value (boiler water temperature). The three-way diverter valve will be in thecylinder heating position until the maximumpossible cylinder temperature has beenachieved. The system then switches over toheating mode. • Resetting: If the burner control unit (seechapter 5.1) reports a fault, the display (pos.14) will indicate “<<RESET”. In this situation,briefly pressing the key will clear the fault.Remove the cause if the burner fault occursrepeatedly (see also chapter 5.1 “Gas burner”).

14 Display (illuminated)The standard display shows the day, the date,the time and the boiler water temperature during operation. A marker bar indicates theactive operating mode. For further displays, see the separate “Operating instructions for contractors -ROTEX control unit”.

Note: All details concerning the ROTEX THETA 23R control unit (adjustment, programming,

parameter etc.) are contained in the separate “Operating instructions for contractors - ROTEX control unit” that issupplied with the GSU/ GCU.

6 Rotary selectorThe rotary selector enables control settings tobe selected and set values to be changed;changes are saved by lightly pressing theselector afterwards.

Turning clockwise (+): increasing adjustmentTurning anti-clockwise (–): decreasing adjustment

Light push: Accept the selected value, saving

Long push: Accessing the programming level (level selection)

7 Set day room temperatureThis is designed to select and adjust the settemperature for “Standard operation”.Setting: in accordance with your individualpreference.

8 Setback room temperatureThis is designed to select and adjust the settemperature for “Setback operation” (nightsetback).Setting: in accordance with your individualpreference.

9 Set DHW cylinder temperatureThis is designed to select and adjust the settemperature for the DHW cylinder.Setting: in accordance with your individualDHW demand. Holding the key down will trigger an exceptional cylinder heating (duringa setback phase).

10 Operating mode selectorYou can select the following operating modes:

1. Temporary operating modes:

HOLIDAY Frost-protected shutdown of DHW and central heating during holidays

ABSENT Short interruption of the heating operation during an absence

PARTY Extended heating operation beyond the regular heating time

2. Automatic mode:

AUTOMATIC Automatic heating and setback mode in accordance with a time switch program

SUMMER Only DHW operation in accordance with a time switch program, heating shutdown with frost protection

3. Constant operating modes:

HEATING Constant heating operation without time limit

REDUCED Constant reduced heat-ing operation without time limit

STANDBY Frost-protected shutdown of DHW and central heating

Application:These operating modes can be selected withthe rotary selector (pos. 6) after pressing theoperating mode selector (pos. 10).

When the maximum cylinder temperature hasbeen reached, the three-way diverter valvewill be switched over to “Heating” (Fig. 3.5.1:connection B; the manual lever (pos. 5.3)points away from the valve body).

Note: Special screed functions are available to heat up an underfloor heating system (see “Operating

instructions for contractors - ROTEX control unit”).

Fig. 4.2.1: Manual mode

4.3 Replacing the control unit

Warning: Electric shocks can cause severe burnsand life-threatening injuries. Before commencing any maintenance work, isolate the heating system from the powersupply by switching the mains isolatorOFF, and safeguard against unintentionalreconnection (pull the power supply plugfrom the plug-in PCB).

Both fixing screws (pos. 16 in Fig. 4.1.1) of theelectronic control unit can be undone by turning them anti-clockwise. This can then bepulled out towards the front (Fig. 4.3.1 and4.3.2).

Fig. 4.3.1 also shows the back of the ROTEXTHETA 23R control unit. When the control unitis reinserted into the control panel, the connection pins will be pushed firmly onto thepermanently fixed socket on the PCB. Thentighten the fixing screws again by turningthem clockwise.

15 Abridged operating instructions

16 Control unit fixing screws

17 Level monitoring indicator for ade-quate water levelThis indicator shows that the cylinder issufficiently full of water. It is switched ON when all three elec-trodes of the level probe (pos. 42 in Fig.2.1.1, Fig. 2.1.2 and Fig. 2.2.1) areimmersed in water and illuminates, aslong as at least two electrodes areimmersed in water. A burner demand will only be enabled ifthe level is adequate.

18 Level warning indicator for low water levelThis indicator shows that the cylinder is insuf-ficiently full of water. It is switched ON whennot at least two of the three electrodes of thelevel probe (pos. 42 in Fig. 2.1.1, Fig. 2.1.2 andFig. 2.2.1) are immersed in. The unpressurisedsector of the cylinder needs to be full of waterto safeguard a reliable DHW provision and toenable the Solaris to operate effectively. Any burner demand will be blocked if the levelis too low.

4.2 Manually adjusting the boiler water temperature

In standard operation, the boiler water controlthermostat will either be set to automatic orconstant operating mode. The boiler watertemperature will be regulated subject toweather conditions. The control unit can be setthe “Manual mode” by holding down the man-ual key for approx. 5 s (pos. 13 in Fig. 4.1.1),for a manual heating up of the heating systemor to temporarily select the boiler water tem-perature manually. The required temperature isadjusted via the rotary selector (pos. 6 in Fig.4.1.1). Setting range: 5-80 °C. In manual mode (Fig. 4.2.1), the three-waydiverter valve (pos. 25 in Fig. 2.2.1) will initiallybe in the “Cylinder heating” position (Fig.3.5.1: connection A; the manual lever (pos. 5.2)will point towards the valve body).

[ 28 ]

press for approx. 5 seconds

Set temperature

change

Return to the original operating mode, standard display, the selected set value is saved

Actual valueRequired setvalue (flashing)

16 Clamping screwsA Front viewB Back view

C Turning anti-clockwise – undoing the clamping screws

D Turning clockwise – tightening the clamping screws

Fig. 4.3.1: Installing/removing the THETA 23R central control unit

4.4 Replacing the boiler control panel

Warning: Electric shocks can cause severe burns and life-threatening injuries. Before

commencing any maintenance work, isolate the heating system from the powersupply by switching the mains isolatorOFF, and safeguard against unintentionalreconnection (pull the power supply plugfrom the plug-in PCB).

To change the boiler control panel, carry outthe following steps: (For the layout of the individual components, see chapter 4)

1) Remove the locking screws of the silencerhood (pos. 35 in Fig. 2.2.1), and lift off the hood (pos. 34 in Fig. 2.2.1).

Caution: Danger risk of scalding! The capillary pipe of the

pressure gauge is in direct contact withthe pressurised heating water. Prior toremoving the pressure gauge, close theball valves on the boiler flow and returnand release the pressure via the boiler fill& drain valve.

2) Close the shut-off valves (pos. 39 in Fig. 2.2.1) in the heating flow and return, connect a hose to the boiler fill & drain valve (pos. 37 in Fig. 2.2.1) and release the water pressure from the boiler.

3) Remove the capillary pipe from the pressure gauge (Fig. 4.4.1). Remove the small volume of water released when undoing the pipe with a kitchen towel.

4) Undo the control panel cover (Fig. 4.4.2).5) Pull all plugs from the PCB (Fig. 4.4.3).

All PCB plugs are coded to prevent errors during reconnection.

6) Lift the sensor leads and connecting cables from the from the cable ducts with strain relief chicanes (Fig. 4.4.4)

7) Undo the control panel from the retainers on the GSU/GCU lid (Fig. 4.4.5) and replace the control panel.

8) Reinsert all sensor leads and connecting cables in the cable duct with strain relief and insert the plugs into the PCB sockets.

9) Refit the control panel cover.10) Insert the pressure gauge capillary pipe. 11) Top up with water, until the required

system pressure has been reached again.12) Open the shut-off valves on the heating

side and vent the system again.13) Refit the silencer hood and secure

with the screws previously removed.

[ 29 ]

Fig. 4.3.2: Removing the control unit

Fig. 4.4.1: Removing the pressure gauge capillary pipe

Fig. 4.4.2: Removing the control panel cover

[ 30 ]

Fig. 4.4.5: Undoing the boiler control panel fixing screws

4.5 Replacing the cables/leads and sensors

Fig. 4.4.4: Removing leads/cables

Fig. 4.5.1: Replacing the return (38) and flow sensor (37)

Fig. 4.4.3: Pulling coded plugs from the PCB



Should a sensor or sensor lead develop a fault,either can be replaced separately, subject to itnot being assembled in the control panel via apermanent plug-in connection with othercables/leads. The cables of the internal equipment components are permanently connected to the respective PCB plug. However, the associated leads/cables can beplugged into the respective component,enabling an easy replacement of the component or lead/cable without majorrewiring.External components (e.g. outside temperaturesensors) or components that are not part of thestandard delivery (e.g. mixers) are connectedto the plugs with screw terminals.

To change the cables/leads, carry out the following steps: (For the layout of the individual components, see chapter 4)

1) Remove the lsilencer hood locking screws(pos. 35 in Fig. 2.2.1), and lift off the hood (pos. 34 in Fig. 2.2.1).

2) Undo the control panel cover (Fig. 4.4.2)3) Lift the sensor lead or connecting cable

from the cable duct with strain relief chicanes inside the control panel (Fig. 4.4.4).

4) Pull all associated plugs from the PCB (Fig. 4.4.3).All PCB plugs are coded to prevent errors during reconnection.

5) Separate the opposite end of the lead/cable from the component concerned (undo plug-in connection).

6) Replace the cable/lead.

Re-assemble in reverse order

Sensors inside the equipment can be replacedin case of fault, with the exception of thecylinder sensor, without opening the controlpanel.The flow and return sensors are pluggedstraight into the sensor. After the plug hasbeen pulled, the sensor can be unscrewedfrom the boiler body and can be replaced (Fig. 4.5.1).

The flue gas temperature sensor is fitted via agland in the flue gas duct of the boiler andconnected with the sensor lead via a flyinglead (Fig. 4.5.2).

The cylinder temperature sensor is directlyconnected at terminals 11/12 of the 12-PINsensor plug inside the boiler control panel.When replacing the leads/cables, follow thesteps 1 to 4. When inserting the sensor intothe sensor well ensure, that the bias spring isbent so it can be effective (Fig. 4.5.3), and thatthe sensor is inserted to the correct depth(observe the marking).

[ 31 ]

Fig. 4.5.3: Insert the cylinder sensor with bent spring 70 cm deep into the sensor well

Fig. 4.5.2: Replacing the flue gas temperature sensor (38) ; the sensor can only be replaced complete with the well.

[ 32 ]

4.6 Replacing the fuse



Should the green ON/OFF indicator (pos. 1 inFig. 4.1.1) not illuminate, although the ON/OFFswitch is ON, and the display stays dark,although the electrical supply to the boiler is‘live’ and the mains isolator to the heating system is switched ON, then most likely thefuse has blown.The fuse is located on the control panel PCB.Initially, pull all plugs from the PCB (see Fig.4.4.3 — proceed according to chapter 4.5,steps 1 to 4). Now remove the 4 screws fromthe control unit enclosure with a screwdriver(Fig. 4.6.1) and remove the upper part of theenclosure (Fig. 4.6.2). Now you can replace thefuse as shown in Fig. 4.6.3. There is a shortcircuit in the system, if the new fuse blowsagain immediately after switching ON. Thatmust first be remedied by a qualified electrician.Fuse type:Only use fuses type 250 V; 6.3 A (slow).

Note: A spare fuse is clipped into the upper part of the enclosure.

4.7 Replacing the PCB

It is possible that the PCB has developed afault, if there is a fault that cannot be removedneither by replacing the ROTEX THETA 23Rcontrol unit (chapter 4.3) nor by replacing thesensors and cables/leads in the control panel(chapter 4.5). After pulling off all plugs fromthe PCB (see Fig. 4.4.3 – proceed as per chapter 4.5, steps 1 to 4), the removal of thefour screws from the control panel (Fig. 4.6.1)and removing the upper part of the enclosure(Fig. 4.6.2), you can pull the PCB upwards outof the control panel and replace it (Fig. 4.7.1).

Important: Ensure that the PCB plug inside the control panel (fault indicator, main

ON/OFF switch) are replace on the newPCB in the correct way (see Fig. 4.8.1). ThePCB must always be free from contamination and scratches.

4.8 Component layout — wiring diagram

All important display elements and electricalconnections are integrated into the boiler control panel. For the layout of the individualcomponents and the wiring diagram, see Fig. 4.8.1.

Fig. 4.6.1: Removing the screws

Fig. 4.6.2: Removing the upper part of the enclosure

Fig. 4.6.3: Replacing the fuse

Fig. 4.7.1: Removing the control panel PCB

[ 33 ]

Fig. 4.8.1: Wiring diagram

1 ON/OFF switch2 Central fault message indicator4 Pressure gauge capillary pipe5 Control unit: Central control unit THETA 23R

17 Level monitoring indicator for adequate water level18 Level warning indicator for low water level19 4-PIN PCB plug with switch cable20 4-PIN PCB plug with fault indicator cable21 4-PIN PCB power plug with connected

power supply cable and earth conductor22 3-PIN PCB plug with pump cable23 Heating circuit pump

24 3-PIN PCB plug for connecting a DHW circulation pump

25 Three-way diverter valve26 4-PIN PCB plug with valve cable27 6-PIN PCB plug with connected burner cable

(power supply for burner control unit and burner fan)

28 Modulating gas burner — burner control unit29 7-PIN PCB plug for connecting a mixer motor

and a mixer circuit pump30 3-PIN PCB plug with communication cable 31 12-PIN PCB plug for connecting sensors,

the BUS and control cable

32 Outside temperature sensor33 Cylinder (DHW) temperature sensor34 8-PIN PCB plug with flue gas sensor lead35 Flue gas temperature sensor36 16-PIN MOLEX plug with flow/return

temperature sensors and fan control cable37 Flow temperature sensor38 Return temperature sensor39 Burner fan40 Control panel PCB41 Label with connection allocations42 Electronic level probe

[ 34 ]

C h a p t e r 5 : T e c h n o l o g y

Fig. 5.1.1: Gas burner of the GSU 25/GCU 25 (front view)

Fig. 5.1.3: Gas burner of the GSU/GCU (rear view)

Fig. 5.1.2: Gas burner of the GSU 35 (front view)

Fig. 5.1.4: Gas burner of the GSU/GCU (view from the left)

5.1 Gas burner

[ 35 ]

Fig. 5.1.5: Gas burner of the GSU/GCU (sectional view)

Fig. 5.1.6: Gas burner connections

Tab. 5.1.1: Burner and burner connection components

1 Burner surface2 Fan 230 V/ 50 Hz3 Safety gas governor4 Gas:air mixture controller5 Gas solenoid valve (1x class B

and 1x class C)6 Gas burner control unit CVBC7 Gas connection G 1/2“ female8 Venturi nozzle with air connection DN 509 Test port “In” - inlet gas pressure

10 Test port “Out” - outlet gas pressure11 Adjusting screw for the gas:air mixture12 Adjusting screw for the gas pressure

governor (underneath the cap)13 Burner flange14/1 Ionisation electrode14/2 Ionisation cable15/1 Ignition electrodes15/2 Ignition cable16 Flame tube insert17 Burner flange gasket (O-ring)18 Flame tube gasket (graphite flat packing)19 Fan flange gasket (silicone flat packing)20 Locking plates never undo these.21 Air inlet hose22 Lid with strain relief

for burner cable (pos. 27, 30 and 36 in Fig. 4.8.1) and safety screw for gas burner control unit

23 Power supply plug (3-pole AMP 230 V) for fan (pos. 27 in Fig. 4.8.1)

24 Plug (5-PIN Molex) for fanspeed control (pos. 36 in Fig. 4.8.1)

25 Gas supply hose26 Power supply plug CVBC

(10-PIN Molex – pos. 27 in Fig. 4.8.1)27 Sensor plug CVBC (16-PIN Molex –

pos. 36 in Fig. 4.8.1)28 Plug for communication cable CVBC

(pos. 30 in Fig. 4.8.1)29 Earth cable connection for the boiler

below the burner flange fixing nut30 Air supply hose

Burner output

The digital ROTEX THETA 23R control unit integrated into the control panel constantlydetermines the required flow temperatureaccording to the selected operating parame-ters and passes that value to the gas burnercontrol unit CVBC. The CVBC calculates therequired burner output from the set value andthe actual flow and return temperatures. Thisdetermined output is converted into a PWMsignal that can be understood by the burnerfan and passed to the fan.The burner fan responds by immediatelymatching the fan speed and therefore the combustion air flow rate to the demand. The gas controller regulates the gas volumeaccordingly (pneumatic interconnection) tomaintain the correct air excess (air factor l)over the entire output range.

Gas:air mixture control

The gas:air mixture (pneumatic interconnection) of the GSU/GCU comprises ofa Venturi nozzle with annular gas inlet and agas pressure governor.It is the task of the gas:air mixture control tomaintain the CO2 progression at any output inaccordance with the selection made at thegas:air mixture adjusting screw (pos 11) and atthe gas pressure screw (pos 12).The gas valve can be adjusted for supply pressure between 5 and 60 mbar (zero governor).A negative pressure results in the centre of theVenturi nozzle that is subject to the combustion air flow rate. This draws the gas,that is available at almost without pressuredownstream of the gas:air mixture controller(zero governor), into the centre of the Venturinozzle. That transports it through the burnerfan to the burner surface, ensuring an optimummixture. This coupled control enables theburner to respond immediately to every fluctuation of the air flow rate by a corresponding change of the gas flow rate.

Checking the burner adjustment

Warning: Risk of explosionsIncorrect handling of gas equipment can lead to gas

explosions: Danger to life Only authorisedgas fitters are allowed to work on gasequipment.

Check the gas type selected at the factory.After the system has successfully passed itstest run, check the burner output during emissions test operation at maximum (fullload) and minimum (standard load) burner output using a flue gas analyser (for emissionstest operation, see chapter 8). Adjust theburner if the actual carbon dioxide concentration deviates by more than ± 0.2 %for the specification. The set carbon dioxidecontent (CO2) is shown in table 5.1.2, Fig. 5.1.7and Fig. 5.1.8.

Important: The emissions test key (see chapter 8) allows the simple selection of the “Full

load” (parameter 02) and the “Standardload” (parameter 04) programmed at theburner control unit parameter level to beselected. These settings can be matched to the individual system requirements by theheating contractor. Modified settingsshould be entered below the type plate onthe settings label.Consider the selected output limits whenchecking the burner settings. Tab. 5.1.2contains details of the permissible settinglimits and the ROTEX factory settings. For individually modified output limits,determine the standard setting valuesfrom Fig. 8.4 and Fig. 5.1.7 or 5.1.8.

[ 36 ]

Construction

The linear gas burner modulating between 5 and 25 kW (GSU 25/GCU 25) or between 8 and 35 kW (GSU 35/GCU 35) of the ROTEXGasSolarUnit/GasCompactUnit is characterised by a very quiet operation, theabsence of wearing parts and clean combustion. The burner is of modular design.

It comprises of the following:- Burner surface (pos. 1)- DC fan without collector (pos. 2)- Venturi mixer nozzle (pos. 8)- Safety gas governor (pos. 3) with

integral gas filter and solenoid valves- Burner control unit with integral ignition

and high limit safety cut-outfunction (pos. 6)

- Burner flange (pos. 13)- Ignition electrode block (pos. 15)- Ionisation electrode (pos. 14)

Resetting the burner

A fault shutdown of the burner is - just like anyother interlocking fault recognised by theburner control unit - displayed as a fault code on the boiler control panel display: “E” and a two digit fault code are displayed.Briefly press the manual key (pos. 13 in Fig.4.1.1) resets the burner.

[ 37 ]

GSU 25/ GCU 25 GSU 35/ GCU 35Gas type Settings for Output CO2 content O2 content Output sett- CO2 O2 content

Test setting1) Load in % ing1) in % speed Load in % in %measurement1) speed in % in kW (+/- 0.2 %) (+/- 0.1 %) in % in kW (+/- 0.2 %) (+/- 0.1 %)

FULL LOAD 100 25.5 9.4 4.2 100 36.1 9.8 3.580 20.2 9.3 4.3 80 28.6 9.6 3.8

STANDARD LOAD 33 7.9 9.2 4.5 33 11.1 9.3 4.424 5.5 9.2 4.5 26 8.5 9.2 4.5

FULL LOAD 100 25.5 9.3 4.0 100 36.1 9.6 3.580 20.2 9.2 4.1 80 28.6 9.4 3.9

STANDARD LOAD 33 7.9 9.1 4.4 33 11.1 8.9 4.824 5.5 9.1 4.4 26 8.5 8.8 4.9

FULL LOAD 100 25.5 11.3 3.8 100 36.1 11.5 3.580 20.2 11.1 4.1 80 28.6 11.2 3.9

STANDARD LOAD 33 7.9 10.6 4.9 33 11.1 10.6 4.924 5.5 10.5 5.0 26 8.5 10.5 5.0

FULL LOAD 100 25.5 11.5 3.8 100 36.1 11.7 3.580 20.2 11.3 4.1 80 28.6 11.4 3.9

STANDARD LOAD 33 7.9 10.8 4.9 33 11.1 10.8 4.924 5.5 10.7 5.0 26 8.5 10.7 5.0

1) Observe warning information! The details in the plain fields correspond to the ROTEX factory settingsTable 5.1.2: Set flue gas values for different gas types

Fig. 5.1.8: Set flue gas values for burner adjustment for GSU 35/GCU 352)

Fig. 5.1.7: Set flue gas values for burner adjustment for GSU 25/GCU 25

2) The data items filled in white represent the ROTEX factory settings

Natural gas E, H

Natural gas LL,L

Propane

Butane

Burner adjustment and matching matching the burner to the gas type

At the factory, the burner is preset to thestated gas type (see adjustment label on thefan casing of the burner). The burner adjustment and the matching of theburner to a different gas type requires theavailability of a flue gas analyser and a pressure meter to measure the gas pressure.

The burner adjustment is checked and matched in accordance with the following steps:

1) Open the screw at the “gas inlet pressure” test port (pos 9) 1/2 a turn anti-clockwise and push on the test hose of the pressure tester

2) Open the gas tap.3) Check the gas inlet static pressure and

compare it with the set value in Tab. 5.1.3 (Fig. 6).

4) Open the heating valves.5) Start the GSU/GCU at the mains isolator.6) Start the emissions test function to ramp

up to full load (see chapter 8).

Note: Carry out a new standard burner adjustment, if the burner fails to start, even though the

power and gas supply are OK and the fluepath is unrestricted:- Turn the mixture adjusting screw

(pos. 11) clockwise up to its end stop (do not tighten!).

- The open the adjusting screw seven turns anti-clockwise and try the start the system again.

- Open the mixture adjusting screw a further three turns, if the burner fails to start and try another start.

7) Connect the flue gas analyser.8) The gas inlet supply pressure must not

drop substantially below the static pressure less the pressure drop in the gas supply hose according to Fig. 5.1.9. The burner output falls if the gas supply pressure is too low. If necessary, check the gas installation.

[ 38 ]

9) Once the flue gas value has stabilised - at the earliest 3 minutes after burner start - adjust the O2 content ± 0.1 % or the CO2

content ± 0.2 % to the selected value in Tab. 5.1.2 or Fig. 5.1.7/5.1.8 using the mixture adjusting screw (pos. 11): - turning anti-clockwise: more gas O2 CO2

- turning clockwise: less gas O2 CO2

10) Start the emissions test function to ramp up to the minimum load (see chapter 8).

11) Once the flue gas value has stabilised - at the earliest 2 minutes after changing the output - compare the actual values with those in Table 5.1.2 or Fig. 5.1.7/ 5.1.8. In case of excessive deviations or if the burner whistles, adjust the O2 content ± 0.1 % or the CO2 content ± 0.2 % to the minimum set value using the gas pressureadjusting screw (pos. 12):- turning anti-clockwise: lower gas output pressure O2 CO2

- turning clockwise: higher gas output O2 CO2

12) Switch the emission test function ON to ramp up to maximum load

13) Check the combustion values. The adjustment is completed if the actual values meet the defaults in step 9. Otherwise repeat steps 9 to 13.

Important: The gas valves are preset at the factory. Generallythe gas pressure governor

requires no further adjustment. Theadjusting screw is hidden under a cover. If the adjusted value deviates excessivelyfrom the set value and the burner tends towhistle, alter the adjustment only in smallsteps (maximum 1/2 turn per adjustment).After each adjustment, wait a while (atleast two minutes) until the flue gasanalyser has settled down again. Set the minimum output to a higher level ifthe burner becomes noisy at the lowestoutput (subject to weather conditions).

Any output adjustments at the system (onlyheating contractor), record these on the adjust-ment label below the type plate (burner load inaccordance with Fig. 8.4). For the burneradjustment values subject to load, see Fig.5.1.7 or Fig. 5.1.8.

[ 39 ]

Fig. 5.1.9: Pressure drop in the gas supply hose

Gas type Inlet pressure in mbar1)

Rated min max.pressure

Natural gas E, H 20 17.0 25.0Natural gas LL, L 20 17.0 25.0LPG2) 50 42.5 57.5Table 5.1.3: Gas supply pressure

1) Notify your gas supply company if the gassupply pressure falls outside the stated range.

2) Where the rated pressures deviate, observethe limits in accordance with the regulationsof the relevant country.

Gas type conversion

Conversion to natural gas LL, L

•To enable a reliable start of a burner that is, as standard adjusted to natural gas E/H, with natural gas LL/L, first open the mixer adjusting screw (pos. 11) one turn anti-clockwise.

•Then adjust the gas volume as described above, so that the O2 or CO2 content shown in Fig. 5.1.7 (GSU 25/GCU 25) or Fig. 5.1.8 (GSU 35/GCU 35) will be maintained.

•Enter the conversion to a different gas type and the selected thermal load (see Fig. 8.4.) on the adjustment label below the type plate on the equipment front and confirm the work by signature.

•Affix the equipment label for the LL/L gas adjustment supplied to the burner fan casing.

Converting from LPG to natural gas

•To ensure the correct function and reliable starting of a burner, set as standard to LPG, with natural gas, first remove the brass restrictor inserted between the safety gas pressure governor (pos. 3) and the Venturi nozzle (pos. 8).

•For this, remove the Venturi nozzle from the burner fan (possible with the burner installed); then remove the three screws that secure the Venturi nozzle on the gas governor. Remove the restrictor and re-assemble the burner in reverse order.

• Initially close the mixture adjusting screw (pos. 11) one turn clockwise.

•Then adjust the gas volume as described above, so that the O2 or CO2 content shown in Fig. 5.1.7 (GSU 25/GCU 25) or Fig. 5.1.8 (GSU 35/GCU 35) will be maintained.

•Enter the conversion to a different gas type and the selected thermal load (see Fig. 8.4.) on the adjustment label below the type plate on the equipment front and confirm the work by signature.

•Affix the equipment label for the natural gas or natural gas LL/L adjustment (request the label from ROTEX) to the burner fan casing.

[ 40 ]

Limiting the maximum burner output

The maximum burner output can be limited atthe boiler control panel by entering an appropriate parameter. After entry of the contractor access code, the maximum speed ofthe burner fan (subject to output) can beadjusted at the “Burner control unit” parameter level for heating mode (parameter2) and DHW heating mode (parameter 3). Theentry is made as a percentage of the ratedequipment output (see operating instructionsfor heating contractors “ROTEX control unit”).

This limit may be advisable, for example if thegas supply company offers a better tariff forequipment with a lower output rating.

Limiting the minimum burner output

The minimum burner output can be regulatedvia the ROTEX THETA 23R control unit byentering an appropriate parameter. After entryof the contractor access code, the minimumspeed of the burner fan (subject to output) canbe adjusted at the “Burner control unit” parameter level (parameter 4). The entry ismade as a percentage of the rated equipmentoutput (see operating instructions for heatingcontractors “ROTEX control unit”).

Raising the minimum burner output may beadvisable, for example, if the flue gas pressuredrop is relatively high, and the flame becomesunstable at minimum load, or if the flue gassystem calculations will not meet requirements at partial load.

Important: Output changes should be entered on the adjustments label below the

type plate at the front of the equipmentand should be confirmed by signature.

[ 41 ]

5.2 Cylinder

The ROTEX GasSolarUnit/GasCompactUnit is aDHW cylinder developed in accordance withthe latest know-how regarding water hygienewith an integral gas fired condensing boiler(Fig. 2.1.1 and 2.1.2).The cylinder is a twin-wall plastic construction. The space between the internaland external wall is filled with thermal foaminsulation. This design results in excellentthermal insulation and very low surface heatlosses.The 3-4 mm thick outer skin is impact andshock-proof and protects the cylinder againstdamage. During commissioning,t he cylinder isfilled once with water. This water is unpressurised and will not be replaced duringuse.

The cylinder water can be heated by a numberof different means:1) by the integral gas fired condensing boiler2) with the GSU via an additionally connected

solar heating system (ROTEX Solaris system)

3) or via additional heat sources that are directly connected to the unpressurised area (e.g. a DHW heat pump)

The DHW is heated inside the spiral heatexchanger constructed from corrugated stainless steel pipe, that is located inside thecylinder and is fully surrounded by the cylinderwater. The specific hygienic water propertiesof the GasSolarUnit/GasCompactUnit arebased on the separation of the unpressurisedcylinder water and the DHW flowing throughthe corrugated pipe heat exchanger.The DHW zone (pos. D) is a combination ofDHW cylinder and instantaneous water heater.The replenishing cold water is initially routedinside the heat exchanger (pos. 18) to the bottom of the cylinder to cool down the solarzone (pos. E) as far as possible. On its pathupwards, the DHW continuously absorbs theheat of the unpressurised cylinder water (pos C), resulting in a distinct temperaturestratification inside the cylinder.

Fig. 05.01.10: Adjusting the ignition and ionisation electrodes

Adjusting the ignition and ionisation electrodes

The electrodes are adjusted at the factory foroptimum performance. Adjust or replace themin accordance with Fig. 5.1.10, should theyhave been bent out of shape.

Please note: The electrodes are brittle and can easily break off if they are bent in a cold

state. For a re-adjustment of the electrodes, remove the burner and heatup the electrodes to incandescence witha blow torch prior to bending.

[ 42 ]

The DHW zone is heated by the condensingboiler (pos. A) via the heat exchanger for cylinder heating (CH-HE pos. 19), throughwhich water flows from the top to the bottom.With the GSU, the SL HW ends approx. 40 cmabove the cylinder floor. Only the DHW zoneabove will be heated by the boiler. The cylinder volume below that point will only beheated in solar applications.With the GCU, the SL HW is drawn right downto the cylinder floor. That ensures that theentire cylinder volume is heated by the boiler,ensuring a higher DHW standby volume.This design offers the particular benefits forthe DHW side offered by theGasSolarUnit/GasCompactUnit.

Optimum water hygiene

Zones that experience little flow or heat exposure on the DHW side are completelyexcluded by the GasSolarUnit/GasCompact-Unit. Deposits of sludge, rust or other sediments that can occur in large volume cylinder, are not possible with this design.Water fed into the cylinder first will also beused first (first-in/first-out principle).

Low on corrosion and maintenance

The cylinder is made from plastic, making ittotally free from corrosion. The DHW and thecentral heating water heat exchangers aremade from high-grade stainless steel (1.4404).Sacrificial anodes or similar corrosion protection measures are not required. Maintenance work, such as the replacement ofprotective anodes or cleaning of the cylinder oranything else in its place are required.During the annual boiler inspection, check thelevel of water and top up, if required (seechapter 6.1).

Economical to operate

The all-round thermal insulation of the cylinderensures low heat losses during operation andtherefore a frugal handling of the applied heating energy.

Stratification inside the cylinder

The spiral shape of the heat exchanger and the direction of flow in the countercurrent principle create a distinct temperature stratification inside the cylinder every timeheat is drawn off or when the cylinder isheated up. A high DHW flow rate can beachieved, even is large volumes of DHW aredrawn off, as high temperatures can prevail inthe upper cylinder area for long periods oftime.With the GSU, the solar zone in the lower areawill cool down and will not be reheated by thegas fired condensing boiler. This improves theefficiency of and the yield from the solar heating system.

Please note: In a few areas, aggressive potable water is supplied by water supply

companies. This water could lead to corrosion damage, even on high-gradestainless steel. Please check with yourwater supply company whether corrosionproblems can occur in their supply areawhen using stainless steel DHW cylinders. For areas with highly corrosive water, weoffer the Sanicube PEX that has proven tobe highly successful over many years (seeROTEX pricelist or the Sanicubebrochure). This may be used in combination with a ROTEX A1 oil or gasfired condensing boiler as an ideal solution for energy and space-savingDHW and central heating with optionalsolar connection.

Low susceptibility to scaling

On the cylinder water side, the scale from theinitial water fill is the only scale that mayoccur. Scale, that progressively reduces theheat transfer performance of other cylinderdesigns, cannot build up on the smooth stainless steel corrugated pipe heatexchanger.Any attached scale will be released throughthermal and pressure expansion and the highflow rate inside the DHW heat exchanger.Consequently, scale will not build up either inthe DHW or in the central heating heatexchangers.

[ 43 ]

Fig. 5.3.1: Standard connection diagram ROTEX GasSolarUnit 1)

5.3 Hydraulic system connection

The descriptions in the following hydraulic diagrams are explained in Tab. 5.3.1 on page 48.

1) The connection diagram shown makes no claim as to its completeness and is no replacement for careful system engineering.

Please note: Risk of scaldingDuring the operation of the Gas-SolarUnit, particularly when

utilising solar energy, cylinder temperatures inexcess of 60 °C can occur. Therefore, install ananti-scalding device on site (DHW mixing facility). The same applies to the Gas-CompactUnit, if cylinder temperatures above60 °C can occur.

[ 44 ]

Fig. 5.3.2: Standard connection diagram ROTEX GasCompactUnit 1)


[ 45 ]

Fig. 5.3.4: optional connection of a pressurised solar heating system to the GasSolarUnit 1)

Fig. 5.3.3: Connection of a wood fired boiler to the GSU/ GCU 1)


* Convert the Solaris control andpump unit RPS 2: Remove the PS2.The PS2 can be used as solar circuitpump. It is connected electricallyin parallel to the PS1.

* Separating the standard connection: Remove UV1 andreconnect it outside the equipment.

[ 46 ]

Fig. 5.3.5: Hydraulic system connection with heating circuit extension 1)

Fig. 5.3.6: Hydraulic system connection GSU with higher solar output proportion 1) 2)

[ 47 ]

Fig. 5.3.7: Hydraulic system connection GCU with solar pre-heating 1)

1) The connection diagram shown makes no claim as to its completeness and is no replacement for careful system engineering.2) Note: The mechanical level indicator in the Sanicube Solaris cannot indicate, with this type of control, since the overflow connection on theGSU is arranged lower down, thereby determining the fill level of the overall control.

[ 48 ]

Abbreviation Explanation Comments/Part no.GSU GasSolarUnit GSU 25 15 70 10

GSU 25 F 15 70 20GSU 35 15 70 21

GSU 35 F 15 70 23GCU GasCompactUnit GCU 25 15 70 30

GCU 25 F 15 70 35GCU 35 15 70 40GCU 35 F 15 70 45

1 Cold water2 DHW3 Heating flow4 Heating returnPK Boiler circuit pump Part of the GSU/

GCU standard deliveryUV1 Three-way diverter valve Part of the GSU/ GCU standard deliverytWW Cylinder temperature sensor Part of the GSU/ GCU standard deliverytV Heating flow temperature sensor Part of the GSU/ GCU standard deliverytR Heating return temperature sensor Part of the GSU/ GCU standard deliverytAG Flue gas temperature sensor Part of the GSU/ GCU standard deliverytAU Outside temperature sensor Part of the GSU/ GCU standard deliverySV Safety valve Part of the GSU/ GCU standard delivery5 Mixer circuit Option

AMK1 Mixer assembly Accessories 15 60 44PMi Mixer circuit pump Part of the standard AMK1 deliveryMi Three-way mixer with servomotor Part of the standard AMK1 deliverytMi Mixer circuit flow temperature sensor Accessories 15 60 62

HEM1 Heating circuit extension module Accessories 15 60 61TSF cylinder temperature sensor Accessories 15 60 63

6 DHW circulation circuit Option PZ DHW circulation pump on-site7 Check valve, non-return valve on-site

8 Solar heating circuit Option Solaris V26 High performance flat-plate collector Accessories 16 43 00

RPS2 Solaris control and pump unit Accessories 164105PS1 Operating pump Part of the standard RPS2 deliveryPS2 Pressure pump Part of the standard RPS2 deliverytS, R Solaris return temperature sensor Part of the standard RPS2 deliverytS Solaris cylinder temperature sensor Part of the standard RPS2 delivery

tS, V Solaris flow temperature sensor Part of the standard RPS2 deliverytK Solaris collector temperature sensor Part of the standard Connect AB delivery

FLS Flow sensor Part of the standard RPS2 delivery

VS Anti-scalding protection on-siteÜV Overflow valve on-siteUV2 Three-way diverter valve Accessories 15 60 34WEx external heat source (e.g. pellet boiler, other solid fuel boiler,

heat pump) on-siteSC 38/0/0 Sanicube as buffer cylinder for external heat sources 16 50 15

PWEx Pump for external heat source circuit on-siteTMV Thermostatic three-way diverter valve for raising

the return temperature on-siteDTR Differential temperature controller e.g. Solaris R2

t1 Heating return temperature sensor to match DTRt2 Buffer cylinder temperature sensor to match DTR

Separation of the solar connection – remove UV1 from the equipment and re-connect on site outside the equipment

SCS 38/16/0 Sanicube Solaris INOX – solar stratification cylinder 16 45 16poss. an alternative cylinder from the Sanicube range

PWT Plate heat exchanger on-siteSV2 Safety valve on-sitePL Primary pump (cylinder, swimming pool) on-site

MV Two-way solenoid valve on-sitePHK Pump for the wood fired boiler circuit on-site9 Solaris cylinder extension set Accessories 16 01 06

Table 5.3.1: Description in hydraulic diagrams

[ 49 ]

Check for unrestricted draining by observing,for example, the way the cleaning fluid drainsout of the combustion chamber.

Note: The condensate that is channelled into the cylinder from the boiler and the flue is slightly

acidic. It is routed into the unpressurisedarea of the cylinder. That way ensures,that in normal operation, the cylinder isalways full. A long-acting neutralisingagent in the cylinder ensures that the liquid draining from the cylinder is pH-neutral. Any residues remain in theunpressurised area of the cylinder.Sedimentation does not normally occur inthe drain line, if the condensate line iscorrectly installed, i.e. with a constantslope.Nevertheless, check that the drain isunrestricted and that the cylinder is full.

C h a p t e r 6 : I n s p e c t i o n a n d m a i n t e n a n c e

6.1 Inspection and maintenance work

Regular inspection and maintenance of yourheating system lowers the energy consumption and safeguards a long service lifeas well as the trouble-free operation of thesystem. For those reasons, have the systeminspected and serviced annually by a competent heating contractor. The serviceshould, where possible, be carried out beforethe heating season. That prevents faults during the heating season from occurring.As part of the annual inspection, the currentstate of the heating system should be established through visual inspection, testsand measurements.Maintenance includes activities, that shouldbe carried out subject to demand, to maintainthe design condition of the system. Thatincludes, for example, cleaning of the burnercomponents, the combustion chamber andheating surfaces, the replacement of wearingparts and the burner adjustment.

To safeguard that this is done regularly,we recommend you take out a maintenance contract.

Specifically, the following work should be carried out annually:

1. Removing the silencer hoodInspection and maintenance require theremoval of the silencer hood from the ROTEXGasSolarUnit.

Caution: Risk of burningBurner and boiler components below the silencer hood can be

very hot. Let the equipment cool down sufficiently before touching these components or wear protective gloves.

Warning: Electric shocks can cause severe burns and life-threatening injuries. Switch OFF

the mains power supply before removingthe silencer hood.

The silencer hood sits at the top of the cylinderand can be lifted off easily after undoing thetwo fixing screws (Fig. 6.1.1).

2. Checking the connections andcables/leadsCheck all components in contact with gas andwater for leaks/soundness as well as potentialdamage; replace, if required.Check all electrical and electronic components,connections and cables and casing components for potential damage; repair, ifrequired.If faults with the electrical or gas supply arediscovered, ask a qualified electrical contractor/gas fitter to remedy the fault.

3. Cleaning the condensate drain and checkingthe cylinder fill levelOpen the condensate drain (connection anddrain lines) and check for contamination;clean, if required and re-seal (Fig. 6.1.2). If a Solaris system is connected and in operation, switch that system OFF and wait,until all collectors have drained.It must be apparent when connecting the overflow connection that the cylinder is completely full. If there is no water at the topedge, top up the cylinder with water. Determine and remedy the reason for the lowlevel (e.g. leak in the Solaris system).

1. Step 4: Remove the fixing screws2. Step 4: Tilt the hood3. Step 4: Lift the hood forward and up

Fig. 6.1.1: Remove the silencer hood

[ 50 ]

Warning: Leaks can lead to gas escaping, resulting in a risk of fire and explosions. Never

remove both locking plates on the burnerflange (sealing paint).

4. Checking the flue gas pathsCheck all flue gas system components fordamage and soundness; repair, if required.

5. Cleaning the combustion chamber andburner

Generally, the burner will operate without creating wear or residues. If contamination orunsatisfactory combustion values are discovered, carry out cleaning and adjustingsteps, as required.

Caution: Danger of burningBurner and boiler parts may be hot. Let the equipment cool

down sufficiently before touching thesecomponents or wear protective gloves.

Caution: Risk of electric shockOnly work on the burner after switching the mains isolator

OFF or after interrupting the power supplyand after the boiler body has cooled downsufficiently.

Only work on the burner after switching themains isolator OFF or after interrupting thepower supply and after the boiler body hascooled down sufficiently.

Fig. 6.1.3: Prior to burner removal Pull off the ventilation air hoseStep 1: Undo the drain plug

Step 2: Visual control of the connection and level

Step 3: Visual check of the drain hose (embrittlement, slope)

Step 4: Check the unrestricted drainingFig. 6.1.2: Check the condensate drains off OK

Fig. 6.1.4: Turn the pulled off ventilation air hose to the side

Fig. 6.1.5: Opening the combustion chamber

1 - Remove the CVBC lid; pull off the connection plug2 - Undo the flange nuts 3 - Pull the burner up4 - Remove the burner

[ 51 ]

6. Clean the cylinder and the silencerhoodThe cylinder and silencer hood are made fromeasy to clean plastic. Only clean with a softcloth and a mild detergent comprising waterand soap.Aggressive cleaning agents containing solvents are unsuitable. These might damagethe plastic surface.

6.2 Temporary shutdown

The GasSolarUnit/GasCompactUnit can betemporarily shut down, if neither central heating nor DHW are required. However, werecommend that the GasSolarUnit/Gas-CompactUnit is switched into the standbymode and to simply log off the heating andDHW demand (see chapter 4, section operating mode selector).

As long as the system is fill, frost protectionwill be assured, subject to the GasSolar-Unit/GasCompactUnit remaining supplied withgas and power and the mains isolator staysON during the frost period.

Drain the equipment, if the gas and powersupply to the GasSolarUnit/GasCompactUnitcannot be assured during a frost period. If therisk of frost prevails only for a few days, whenthe gas and power supply cannot be assured,then the GasSolarUnit/GasCompactUnit maynot need to be drained on account of its excellent thermal insulation, subject to thecylinder being regularly checked and its watertemperature does not drop below +3 °C. However, there will then be no frost protectionfor the heat distribution system.

Draining the system

Should it prove necessary to drain the systemcompletely, drain the heating circuit heatexchanger, the cylinder and the DHW heatexchanger.

Draining the cylinder

To drain the cylinder, attach the hose with thehose connector supplied (in the accessoriespack) to the solar return (pos. 8 in Fig. 2-1-1)and let the cylinder empty completely.

Note: Only use the hose connector supplied, as this automatically opens the foot valve on

connection. Where a Solaris system isconnected, the system can also bedrained via the boiler fill & drain valveattached to the Solaris return.

Draining the heating circuit heatexchanger and the DHW heat exchanger

To drain both heat exchangers, separate theheating flow and return as well as the coldwater supply and the hot water outlet. Thenconnect hoses routed downwards, so that thehose opening is as close to the floor level aspossible. Drain the heat exchanger accordingto the pipette principle.

Remove the two M6 fixing nuts from theburner flange. The burner can then be liftedout of the combustion chamber (Fig. 6.1.5).To clean the combustion chamber, flush it out -after sealing off the direct condensate drainhole inside the combustion chamber - from thetop with clean water, until all residues havebeen removed from the inside of the combustion chamber and the ribs of the fluegas heat exchanger. (A steam cleaner may alsobe used to remove harder deposits.) Check the burner as follows:• Clean the burner surface

(cloth, plastic brush)• Visual check of the ignition and ionisation

electrodes (damage, gaps in accordance with Fig. 5.1.10)

• Fit the burner back into the combustion chamber

Please note: When re-installing the burner, remember to fit the fixing earth strap underneath

the nut.

• Ensure that the gas supply pipe is sound and in perfect condition.

• Run the burner for approx. 5 minutes in emission test mode and then analyse the combustion with reference to the following values:1. Flue gas temperature at the flue test port (<120 °C).2. CO2 content in accordance with Fig. 5.1.7/5.1.8 ± 0.2 %) or O2 content ± 0.1 %3. CO content (< 50 ppm)

• Correct the burner adjustment in accor-dance with chapter 5.1, if the flue gas test results in deviating values.

Note: We recommend that all actual values and work carried out are entered into the maintenance

record supplied (inside back cover),together with the date and signature andposition this record clearly visible to theflue gas inspector [where appropriate].

Troubleshooting

The integral ROTEX THETA 23R boiler controlunit and the gas burner control unit CVBC areequipped with fault detection programs thatsubstantially simplify troubleshooting.A fault recognised by these devices will beindicated as a fault code on the control unitdisplay. Certain types of faults will also bestored by these devices to enable the determination later, at what time that faultoccurred (see operating instructions “ROTEXcontrol unit”).

Note: When referring a problem to the ROTEX Service, always quote the equipment serial number from

the type plate (lower r.h. side of the cylinder).

[ 52 ]

Tab. 7.1 summarises the meaning of thesefault codes. Faults recognised by the burnercontrol unit CVBC that lead to the burner beinglocked out, are not only indicated on the control unit display but also by a fault indicatoron the boiler control panel (pos. 2 in Fig. 4.1.1).These faults may be reset five times withinone hour by lightly pressing the manual key(pos. 13 in Fig. 4.1.1). For such faults, alwaysinvestigate and remove the respective cause.Faults recognised by the CVBC burner controlunit are displayed as long as the fault persists.The equipment will continue to work normallywhen the reason for the fault no longer exists.In accordance with the fault message, checkthe sensors, ignition and initialisation electrode or other components identified bythe fault message as well as all associatedleads/cables. Replace them, if required.Tab. 7.2 lists further faults and their causestogether with information regarding possibleremedies.

C h a p t e r 7 : T r o u b l e s h o o t i n g

[ 53 ]

Fault code Description Type of fault Comments10-0 Outside sensor Cable break10-1 Outside sensor Short circuit12-0 Mixer circuit flow sensor Cable break Mixer circuit pump will be switched OFF;

the mixer motor goes to zero volt12-1 Mixer circuit flow sensor Short circuit Mixer circuit pump will be switched OFF;

the mixer motor goes to zero volt13-0 DHW cylinder sensor break13-1 DHW cylinder sensor short circuit14-7 Modem contact Fault indication15-7 Burner blocking contact Fault indication16-0 Flue gas sensor Cable break16-1 Flue gas sensor Short circuit16-7 Flue gas sensor Fault indication30-2 Burner No shutdown30-3 Burner No start33-5 Flue gas temperature Exceeded70-0 Address Address conflict70-1 Activity No T2B signal70-6 Communication between the THETA

and the burner control unit CVBC Cable break71-0 EEPROM Internal error71-1 EEPROM faulty Internal errorE 01 Burner control unit CVBC Interlocking fault No flame recognised within the 5 possible starting

attemptsE 02 Burner control unit CVBC Interlocking fault Incorrect flame signal – ionisation current outside

the permissible rangeE 03 Burner control unit CVBC Interlocking fault high limit safety cut-out fault — excessive

flow temperatureE 05 Burner control unit CVBC Interlocking fault No speed signal from the burner fan

within 10 secondsE 08 Burner control unit CVBC Interlocking fault Fault in the flame monitoring routineE 10 Burner control unit CVBC Interlocking fault EEPROM communication errorE 11 Burner control unit CVBC Interlocking fault Faulty sensor adjustment procedure for the

electronic high limit safety cut-out function or return temperature longer than 3 minutes more than 3K higher than the flow temperature

E 19 Burner control unit CVBC Interlocking fault Micro-processor H – I/O errorE 20 Burner control unit CVBC Interlocking fault Micro-processor L – I/O errorE 21 Burner control unit CVBC Interlocking fault Micro-processor H – A-D converter errorE 22 Burner control unit CVBC Interlocking fault Micro-processor L – A-D converter errorE 25 Burner control unit CVBC Interlocking fault Internal errorE 26 Burner control unit CVBC Interlocking fault Five times flame tear-off within 4 minutesB 09 Burner control unit Temporary fault Fault during the gas valve checking routineB 30 Burner control unit Temporary fault Flow sensor short circuitB 31 Burner control unit Temporary fault Flow sensor breakB 34 Burner control unit Temporary fault Voltage too low (<185 V)B 35 Burner control unit Temporary fault Fluctuating mains frequency (in excess of ± 2 Hz)B 37 Burner control unit Temporary fault Internal errorB 43 Burner control unit Temporary fault Return sensor short circuitB 44 Burner control unit Temporary fault Return sensor breakB 99 Burner control unit Temporary fault Internal communication between THETA

and CVBC interrupted

Table 7.1: List of possible fault codes

[ 54 ]

Fault Possible Cause Possible remedyHeating system not operational Power supply interrupted Switch ON the mains electrical isolator - no displaySwitch ON the mains electrical Check/replace control unit fuse Check/switch ON the domestic supply circuit breakerisolator of the installation room The heating system fails to heat up The central heating standby is switched OFF - check the position of the ON/OFF switch, time program

etc, incorrect controller setting Check the demand parameters (see operating instructions “ROTEX control unit”)

The heating system fails to heat The heating curve is too low Increase the parameter (see operating instructions up sufficiently “ROTEX control unit”)The DHW fails to heat up The DHW heating standby is switched OFF Check the setting of the operating mode selector, time

program or the demand parameters (see operating instructions “ROTEX control unit”)

The DHW fails to heat up sufficiently The cylinder heating temperature is too low Increase the set DHW temperature (see the abridged operating instructions or the operating instructions “ROTEX control unit”)

Excessive draw-off rate Reduce the draw-off rate; limit the flow rateThe burner output is too low see fault: the max. burner output is too low

The burner fan does not start in spite of no burner fan power supply audibly click the 3-pole fan plug in burner demandCheck the voltage at terminals L-N on the 3-pole plug; audibly click the 5-PIN fan plug in

The control unit plug-in connections are Check the correct plug seating in the control panel are loose and at the burner control unit Push the plug fully inFan motor faulty (bearing seized) Replace the burner fan

no ignition Ignition electrodes short circuited adjust or replaceIgnition electrodes are too far apart AdjustIgnition electrodes are contaminated and/or damp CleanIgnition electrodes burned out ReplaceInsulation body cracked Replace ignition electrodeIgnition cable burned out 1. Replace the cable

2. Identify and remove the causeBurner control unit faulty Replace

Burner does not start in spite of No burner power supply, cable faulty Check cable for damage and the correct seating of the plug burner demand

or plug is incorrectly inserted in the control panel and at the burner control unitPush the plug fully in

The flame monitor switches the burner OFF Check the position of the ionisation electrode, ionisation cable (damage, seating)

No gas pressure Check the gas connectionAir in the gas supply line Vent the gas supply pipeThe gas valve fails to open Check the plug-in connection between the burner

control unit and the gas valve, poss. re-align the connecting pins check the gas valve (vacuum at the output pressure test port during purging, zero pressure during ignition)- possibly replace,- otherwise replace the burner control unit

No ignition Check ignition cable plug-in connectors Check the position of the ignition electrodes

Loud operating noise Burner incorrectly adjusted Check and correct the burner adjustmentBearing damage - burner fan Reduce the maximum output

- possibly replaceThe max. burner output is too low Incorrect parameter setting Adjust the output parameter

(see operating instructions “ROTEX control unit“: Burner control unit parameter level)

Excessive air/flue gas pressure drop Check lines for contaminationposs. use larger cross-section for ventilation air pipe and/ or flue

Table 7.2: Fault removal

[ 55 ]

Footnotes regarding Table 8.1 Specification

1) at rated output, 80 °C flow temp., 65 °C cylinder temp., 45 °C DHW temp. and 10 °C cold water temp.2) Explanation: The specific water flow rate to EN 625 is the cold water flow rate when raising the average temperature by 30 K, that can be delivered by the GasSolarUnit/GasCompactUnit in the course of twoconsecutive drawings of 10 minutes duration respectively, starting from a primary temperature of 65 °C. This is based on the standard delay of 20 minutes between drawings. The GasSolarUnit/GasCompactUnitachieves this value even at substantially shorter delays.

[ 56 ]

C h a p t e r 8 : S p e c i f i c a t i o n

Standard detailsTotal cylinder capacity litres 500 500 500 500Weight (empty) kg 124 125 121 128Total weight (wet) kg 624 625 621 628Dimensions (L x W x H) cm 79 x 79 x 181 79 x 79 x 181 79 x 79 x 181 79 x 79 x 181Max. permissible DHW cylinder temperature °C 85 85 85 85Standby heat loss kWh/24 h 1.8 1.8 1.8 1.8Maximum operating pressure bar 10 10 10 10DHW heat exchanger material Stainless steel Stainless steel Stainless steel Stainless steelDHW heatingDHW capacity litres 24.5 24.5 24.5 24.5DHW heat exchanger surface area m2 5,5 5.5 5.5 5.5Average specific output W/K 2 470 2 470 2 470 2 470Cylinder primary heat exchanger (stainless steel)Heat exchanger water content litres 10.4 10.4 10.4 19.5Primary heat exchanger surface area m2 2,3 2.3 2.3 4.3Average specific output W/K 1040 1040 1040 1950Solar central heating backup (stainless steel)Heat exchanger surface area m2 0,43 0.43 – –Average specific output W/K 200 200 – –Thermo-technical performance data (stainless steel)Performance factor NL to DIN 4708 1) 2.1 2.3 4.0 4.4D value (spec. water flow rate) to EN 625 2) l/min 27 29 33 39Continuous output to DIN 4708 Qn kW 25 29 25 35Max. draw-off rate for 10 min (at (TKW = 10 °C/Tcyl = 60 °C/TWW = 40 °C) l/min 22 23 29 31DHW volume without re-heating at 15 l/mindraw-off rate (TKW = 10 °C/TWW = 40 °C/Tcyl = 60 °C) litres 220 220 412 412DHW volume with re-heating at rated output and 15 l/min draw-off rate (TKW = 10 °C/TWW = 40 °C/Tcyl = 60 °C) litres 590 1400 1180 unlimitedPeak water volume in 10 min litres 220 230 290 310Boiler parametersRated output kW 5.4-25.0 8.0-35.0 5.4-25.0 8.0-35.0Rated thermal load kW 5.5-25.5 8.5-36.1 5.5-25.5 8.5-36.1Boiler type B23 / C43x / C63x / C43 / C63

Product ID CE-0085 BM 0065NOx class 5 5 5 5Electrical specification V/Hz 230/50 230/50 230/50 230/50Power consumption(incl. heating circuit pump) W max. 127 max. 159 max. 127 max. 159Protection IP 20 20 20 20Water content litres 5.5 5.5 5.5 5.5Maximum permissible operating pressure bar 3.0 3.0 3.0 3.0Maximum permissible operating temperature °C 85 85 85 85Maximum boiler efficiency % 110 110 110 110Balanced flue connection diameter mm 80/125 80/125 80/125 80/125Pipe connectionsCold and hot water inches 1” male 1” male 1” male 1” maleHeating flow and return inches 1” female 1” female 1” female 1” femalePart no. 15 70 10 15 70 21 15 70 30 15 70 40

Specification GasSolarUnit and GasCompactUnit GSU 25 GSU 35 GCU 25 GCU 35

Table 8.1: Specification

[ 57 ]

Gas type Inlet pressure in mbar1)

Rated min maxpressure

Natural gas E, H 20 17.0 25.0Natural gas LL 20 17.0 25.0LPG2) 50 42.5 57.5Table 8.2: Permissible gas supply pressure

1) Notify your gas supply company if the staticgas supply pressure falls outside the statedrange.

2) Where the rated pressures deviate, observethe limits in accordance with the regulationsof the relevant country.

Please note: The pressure drop on the flue gas side must not exceed 200 Pa, that on the ventilation air

side 50 Pa.

Country of destination Equipment category Rated supply pres-sure

in mbarNatural gas LPG Natural gas LPGDE I 2 ELL I 3 B/P 20 50AT, CH I 2 H I 3 B/P 20 50DK, FI, NO, SE I 2 H I 3 B/P 20 28-30/30GB, GR, IE, IT I 2 H I 3+ 20 28-30/37CH, ES, PT I 2 H I 3+ 20 28-30/37NL I 2 L I 3 B/P 25 28-30/30LU I 2 E I 3 B/P 20 50FR I 2 Esi I 3 P 20/25 37US I 2 E(S)B I 3 P 20/25 37Table 8.3: Summary of countries of destination, equipment categories and associated gas supply pressures

Explanations regarding Table 8.1:1)At rated output, 80 °C flow temperature, 65 °C cylinder temperature, 45 °C DHW temperature and 10 °C cold water temperature2) Explanation: The specific water flow rate to EN 825 is the cold water flow rate when raising the average temperature by 30 K, that can be delivered by the GasSolarUnit/GasCompactUnit in the course of two consecutive drawings of 10 minutes duration respectively, starting from a primary temperature of 65 °C. This is based on the standard dwell time of 20 minutes between drawings. The GasSolarUnit/GasCompactUnitachieves this value even at shorter delays.

[ 58 ]

Fig. 8.1: Residual head GSU 25, GCU 25 (heating side)

Fig. 8.2: Residual head GSU 35, GCU 35 (heating side)

[ 59 ]

Fig. 8.4: Permissible burner loads for GSU/GCU, the details highlighted in white represent factory settings

Fig. 8.3: Required flow rate subject to the heating output and the design temperature spread

[ 60 ]

Fig. 8.5: Pressure drop inside the DHW heat exchanger subject to the draw-off rate

Fig. 8.6: Available draw-off volume subject to the draw-off rate 1)

1)Cylinder temperature 60 °C, draw-off temperature 40 °C, cold water temperature 10 °C, reheating at rated output

[ 61 ]

Fig. 8.7: Resistance curves of the temperature sensors 2)

Table 8.4: Resistance values of the temperature sensors2)

Sensor type Actual temperature in °C-20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120

Sensor resistance in Ohm according to standard or manufacturer’s detailsPTC 1386 1495 1630 1772 1922 2080 2245 2418 2598 2786 2982 3185 3396 – –

Pt-1000 – – 1000 1039 1077 1116 1155 1194 1232 1270 1308 1347 1385 1423 1461NTC 98660 56250 33210 20240 12710 8195 5416 3663 2530 1782 1278 932 690 519 395

2) Temperature sensor:PTC resistance: Outside temperature, DHW cylinder temperature, mixer circuit temperaturePt 1000 resistance: Flue gas temperatureNTC resistance: Flow temperature, return temperature

Temperature in °C

[ 62]

Fig. 8.8: Wiring diagram

16 pol. MicrofitVorlauf1Rücklauf1MischerBauseitsGebläseFeuerungsautomatKesselerdungNetzAbgas1SpeicherfühlerAussenfühlerMischerfühler rRaumstation oder weitere THETA ReglerGasventilSpeicherAussenMischerModemBR-SperreHauptschalterElektrodenrelaisSiehe Blatt 2/2MasseMax.Min.ResetLampe1Lampe2SammelstörungPegel niedrigPegel in Ordnung

[ 63 ]

M a i n t e n a n c e l o g

Please tick the maintenance work done and enter actual values, as appropriate. Observe the information in chapters 6 and 5.1.

Inspection and maintenance workInitial 1. Maintenance 2. Maintenance 3. Maintenance 4. Maintenancestart-up

DateLeak test heating line connectionsLeak test DHW line connectionsSoundness test gas connectionVisual inspection of electronic componentsChecking the tightness of electrical connectionsFunction test and cleaning the condensate drainTesting the flue gas connectionCleaning the combustion chamberCleaning and checking the burnerChecking the burner adjustment (correct gas type)Testing the gap of the ionisation and ignition electrodesTesting the burner inlet pressureCleaning the cylinder and silencer hood

Starting the burner and testing values- Carbon dioxide (CO2) in the flue- Oxygen (O2) in the flue- Carbon dioxide (CO2) in the ventilation

air (annular gap test)- Flue gas temperature in the flue- Testing the inrushing air- Carbon monoxide (CO)

Confirm maintenance(company stamp, signature)

Changes made to the control unit setting parameters/additional information regarding the heating system

Date Signature Comments

Check measurement

The GasSolarUnit/GasCompactUnit isequipped with a simply selected automaticfunction for check measurements (e.g. emissions test).These are described in the abridged operatinginstructions and in detail in the separate“Operating instructions for heating contractors“ROTEX control unit” (see also the schematicdiagram in Fig. 9.2).

Pressing the Manual key (pos. 13 in Fig.4.1.1) ramps up the boiler to its maximumboiler water temperature for 20 min. Pressingthe key a second time during that runtimeswitches the burner back to minimum load.The runtime for this setting will start again at20 minutes. Pressing the key again during the20 min. period terminates the emission test.

008.

1507

644

· Sub

ject

to te

chni

cal m

odifi

catio

ns· 0

6/20

06· I

n ca

se o

f dis

crep

anci

es, t

he o

rigin

al m

anua

l sha

ll ap

ply

· 008

.150

7649

· 12/

2005

C h a p t e r 9 : F o r t h e f l u e g a s i n s p e c t o r

Burner load Rated output Flue gas mass flow rate Flue gas temperature Available draughtin kW in kW in g/s in °C in Pa

40/30 °C 80/60 °CNatural gas E,HNatural gas LL,LLPG 40/30 °C 80/60 °C5.5 5.9 5.5 2.31 2.31 2.09 35 65 30

10.0 10.7 10.0 4.20 4.43 3.80 37 68 11015.0 16.0 14.9 6.30 6.31 5.71 40 72 17020.0 21.1 19.8 8.40 8.41 7.61 43 74 20025.5 26.8 25.0 10.71 10.73 9.70 46 78 2008.5 9.0 8.0 3.57 3.58 3.23 41 71 40

15.0 15.9 14.8 6.30 6.31 5.71 43 74 12020.0 21.1 19.6 8.40 8.42 7.61 46 78 18025.0 26.2 24.4 10.50 10.52 9.51 49 80 20030.0 31.2 29.2 12.60 12.62 11.41 51 82 20036.1 37.2 35.0 15.16 15.19 13.73 52 84 200

Table 9.1: Triple value for sizing the chimney (CO2 adjustment in accordance with Table 5.1.2 or Fig. 5.1.7 and Fig. 5.1.8)

Fig. 9.1: Flue gas mass flow/burner output ROTEX GasSolarUnit/GasCompactUnit

Flue sizing details

R O T E X H e a t i n g S y s t e m s G m b HLangwiesenstraße 10 · D-74363 GüglingenTel +49 (71 35) 103-0 · Fax +49 (71 35) 103-200e - m a i l i n f o @ r o t e x . d e · w w w. r o t e x . d e

Fig. 9.2: Abridged manual using symbols Emissions test mode

Current heat sourcetemperature

Remaining timefrom activation

Cancel emissions test prematurely

Current heat sourcetemperature

Remaining timefrom activation

GSU 25/GCU 25

GSU 35/GCU 35

Documents

ROTEX GasSolarUnit · 2017. 10. 31. · The ROTEX GSU/GCU is a gas fired condensing boiler (A), that is integrated in a 500 litre DHW cylinder (B). The DHW cylinder is filled with