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Worcester wiring guide Greenstar gas-fired boilers

Gas Boiler Wiring Guide

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Page 1: Gas Boiler Wiring Guide

Worcester wiring guideGreenstar gas-fired boilers

Page 2: Gas Boiler Wiring Guide

Contents

Introduction Page 4

Greenstar Ri Regular Page 5

Greenstar CDi Regular Page 17

Greenstar CDi System Page 29

Greenstar CDi Combi Page 42

Greenstar FS CDi Regular Page 53

Greenstar HF CDi Combi Page 65

Greenstar Si Combi Page 71

Greenstar i Junior Combi Page 82

Greenstar i System Page 93

Notes Page 105

Page 3Worcester wiring guide Greenstar gas-fired boilers

Page 3: Gas Boiler Wiring Guide

Page 4 Worcester wiring guide Greenstar gas-fired boilers

Introduction

NEW COMPLETE SYSTEM INSTALLATIONSIf a new complete heating system installation is in a new build property or it is

a first time installation in an existing property, then the heating system must

conform to current building regulations Part L1a. All new heating systems in

dwellings must have at least two heating zones. Each of these zones will be

controlled by a thermostat and zone valve. An alternative would be individual

electronically controlled TRVs. If the hot water is provided from a storage

system then the DHW cylinder will require separate time and temperature

control. All radiators must have TRVs fitted in all rooms except bathrooms and

rooms with thermostats. The exception to this are single storey, open plan

dwellings where the living area is more than 70% of the total useable floor

area. Then this type of dwelling can be controlled as one zone.

EXISTING INSTALLATIONS

For boiler replacements on an existing system, it is not necessary to zone the

upstairs and downstairs differently, compliance with the zone requirements

can be achieved by a single room thermostat or programmable room

thermostat. While the system is drained down, TRVs may be fitted to all

rooms except the bathrooms and the room with the thermostat.

Page 4: Gas Boiler Wiring Guide

Page 5Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri Regular2 x 2 Port Valves (S-Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Room T/Stat

L

N

Time Controller

HW

ON

CH

ON

M~L

NE

M~L

NE

CylinderZone Valve

HeatingZone Valve

External Pump

L

EN

reset max

L N LPNPLR

GreenstarRi Regular

Double PoleFused Spur

L

EN

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 5: Gas Boiler Wiring Guide

External Pump

L

EN

reset max

L N LPNPLR

GreenstarRi Regular

Double PoleFused Spur

L

EN

230V MainsVoltage

CylinderT/Stat

Green/YellowBlueWhiteGreyOrange

EN

Mid PositionValve

L

N

Time Controller

HW

OFF

HW

ON

CH

ON

C

1 2

L N E 4 5 6 7 8 9 10

N

Room T/Stat

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

Page 6 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri RegularMid Position Valve (Y-Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 6: Gas Boiler Wiring Guide

External Pump

L

EN

reset max

L N LPNPLR

GreenstarRi Regular

Double PoleFused Spur

L

EN

230V MainsVoltage

CylinderZone Valve

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

HeatingZone 1 Valve

M~L

NE

Room T/StatZone 1

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

CH

Zon

e 2

ON

L

N

Time Controller3 Channel

HW ON

CH Zone 1 ON

Page 7Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri Regular3 x 2 Port Valves (S-Plan Plus)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 7: Gas Boiler Wiring Guide

External Pump

L

EN

reset max

L N LPNPLR

GreenstarRi Regular

Double PoleFused Spur

L

EN

230V MainsVoltage

Room T/StatZone 1

HeatingZone 1 Valve

L

N

Time Controller

CH

Zon

e 1

ON

CH

Zon

e 2

ON

N

L N E 4 5 6 7 8 9 10

M~L

NE

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

Page 8 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri Regular2 x Radiator Heating Zones

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 8: Gas Boiler Wiring Guide

External Pump

L

EN

reset max

L N LPNPLR

GreenstarRi Regular

Double PoleFused Spur

L

EN

230V MainsVoltage

Room T/StatZone 1

HeatingZone 1 ValveC

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

M~L

NE

CylinderZone Valve

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControlerTwin Channel

HW

ON

CH

Zon

e 1

ON

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

Page 9Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri Regular2 x 2 Port Valves & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 9: Gas Boiler Wiring Guide

External Pump

L

EN

reset max

L N LPNPLR

GreenstarRi Regular

Double PoleFused Spur

L

EN

230V MainsVoltage

Room T/StatRadiators Zone

RadiatorsZone Valve

N

L N E 4 5 6 7 8 9 10

M~L

NE

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerSingle Channel

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

Page 10 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri RegularZoned Radiator & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 10: Gas Boiler Wiring Guide

External Pump

L

EN

reset max

L N LPNPLR

GreenstarRi Regular

Double PoleFused Spur

L

EN

230V MainsVoltage

C

1 2

L N E 4 5 6 7 8 9 10

CylinderT/Stat

L

N

Time ControllerSingle Channel

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

Page 11Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri RegularSingle Hot Water Zone (Vented Cylinder)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 11: Gas Boiler Wiring Guide

External Pump

L

EN

reset max

L N LPNPLR

GreenstarRi Regular

Double PoleFused Spur

L

EN

230V MainsVoltage

L N E 4 5 6 7 8 9 10

L

N

Time ControllerSingle Channel

N

Room T/Stat

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

Page 12 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri RegularSingle Heating Zone

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 12: Gas Boiler Wiring Guide

reset max

L N LPNPLR

GreenstarRi Regular

Double PoleFused Spur

L

EN

N

NN

N

CH onCH onHW on

HW onN

N

L3

4

L

L

L

L

L

L

S/L

NO

NO

NO

N/U = Not Used

BOILER

2.5A Fuse - RS Components stock no 415-604

Warning! 240V - Isolate electrical supplybefore removing wiring centre cover.

HW PUMP

CH PUMP

PROGRAMMER

FROST T/STAT

ROOM T/STAT

CYLINDERT/STAT

FUSE2.5A

Frost T/Stat(if required)

Room T/Stat

HW Pump

CHPump

CH/HWProgrammer

Cylinder T/Stat

UPP 15-50 PUMP PLAN - WIRING CENTRE CONNECTIONS

(N/U)

(N/U)

(N/U)

1

1

1

2

2

2

(N/U)

N

(N/U)(N/U)

(N/U)

N

N

C

C

Demand

Deman

d

Deman

d

C

P/L

N

L

230V MainsVoltage

Earth terminal for:Controls, Boiler, PumpsElectrical Mains Supply

Page 13Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri RegularGrundfoss Pump Plan

IMPORTANT NOTEThe pump over-run of the pump plan module, causes the hot water pump to run regardless of thehot water cylinder demand, to dissipate boiler heat. Worcester will only recommend theGrundfoss pump plan system on a vented cylinder.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 13: Gas Boiler Wiring Guide

MA

INS

BO

ILERPU

MP

SMARTFIT FROSTPROTECTION

ROOM

PORTACCESSORY

S PLAN

A

CHVALVE

(S)CYLINDERSENSOR

SMARTFITROOM UNIT

POLARITYFREE

3 PORTVALVE

(Y)

HWVALVE

(S)

Y PLAN

UNIT

HW VALVE (S)

CH VALVE (S) CYLINDERT/STAT

reset max

L N LPNPLR

GreenstarRi Regular

External Pump

L

EN

Double PoleFused Spur

L

EN

L

N

LSL

PL N

N

L

Smartfit Layout:Example shown S Plan configuration

230V MainsVoltage

Page 14 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri RegularSmartfit Control Pack

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 14: Gas Boiler Wiring Guide

reset max

L N LPNPLR

GreenstarRi Regular

reset max

L N LPNPLR

GreenstarRi Regular

Shunt Pump

Junction Box/Wiring CentreSwitched Live/

DemandN EL

Double PoleFused Spur

L

EN

L

EN

C C

Shunt Pump

L

EN

C

NO

NC

230V ACDouble Pole Relay

Header LimitThermostat

Wiring from Zone/s Controls

Example relay shown is a Double Pole Mains Voltage Relay. This isolates the Boilers electrically in case of a fault condition.

IMPORTANT NOTE:The Relay should be mounted within a suitable electrically safe housing.

C C

NC NCNO NO

CoilLive

CoilNeutral

230V MainsVoltage

Page 15Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri RegularCascaded boilers with low loss header

NOTEA pump must be wired to each boiler for pump over-run to dissipate heat from within the boiler.The connections are Live of pump to LP and Neutral of pump to NP and the Earth of the pump tothe Earth point of each boiler.

HEADER LIMIT THERMOSTATThis cuts the Demand to the boilers in the event of excessive temperature within the Header dueto lack of circulation. Ideally this should be set to 90º C.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 15: Gas Boiler Wiring Guide

reset max

GreenstarRi Regular

C

1 2

N CylinderT/Stat

Room T/Stat

L

N

Time Controller

HW

ON

CH

ON

HeatingZone Valve

L

EN

External Pump

Double PoleFused Spur

L

EN

L N E 4 5 6 7 8 9 10

Pipe T/StatFrost T/Stat

L N LPNPLR

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 16 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Ri RegularFrost Protection

NOTEA frost thermostat is normally used to protect locations which have no heat source e.g. a garage.It is recommended that a pipe thermostat is also used (wired in series with the frost thermostat)to avoid long periods of heat demand if the air temperature does not satisfy the frost thermostat.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 16: Gas Boiler Wiring Guide

Greenstar CDi Regular

L NSN LS LR

LZ NZ

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Room T/Stat

L

N

Time Controller

HW

ON

CH

ON

M~L

NE

M~L

NE

CylinderZone Valve

HeatingZone Valve

Double PoleFused Spur

L

EN

L

EN

E

External Pump

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 17Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi Regular2 x 2 Port Valves (S-Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 17: Gas Boiler Wiring Guide

Greenstar CDi Regular

L NSN LS LR

LZ NZ

Double PoleFused Spur

L

EN

L

EN

E

CylinderT/Stat

Green/YellowBlueWhiteGreyOrange

EN

Mid PositionValve

L

N

Time Controller

HW

OFF

HW

ON

CH

ON

C

1 2

N

Room T/Stat

L N E 4 5 6 7 8 9 10

External Pump

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 18 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi RegularMid Position Valve (Y-plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 18: Gas Boiler Wiring Guide

Greenstar CDi Regular

L NSN LS LR

LZ NZ

External Pump

Double PoleFused Spur

L

EN

L

EN

E

CylinderZone Valve

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

HeatingZone 1 Valve

M~L

NE

Room T/StatZone 1

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

CH

Zon

e 2

ON

L

N

Time Controller3 Channel

HW ON

CH Zone 1 ON

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 19Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi Regular3 x 2 Port Valves (S-Plan Plus)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 19: Gas Boiler Wiring Guide

Room T/StatZone 1

HeatingZone 1 Valve

L

N

Time Controller

CH

Zon

e 1

ON

CH

Zon

e 2

ON

Greenstar CDi Regular

L NSN LS LR

LZ NZ

Double PoleFused Spur

L

EN

L

EN

E

N

L N E 4 5 6 7 8 9 10

M~L

NE

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

External Pump

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 20 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi Regular2 x Radiator Heating Zones

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 20: Gas Boiler Wiring Guide

Room T/StatZone 1

HeatingZone 1 Valve

Greenstar CDi Regular

L NSN LS LR

LZ NZ

Double PoleFused Spur

L

EN

L

EN

E

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

M~L

NE

CylinderZone Valve

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerTwin Channel

HW

ON

CH

Zon

e 1

ON

External Pump

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 21Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi Regular2 x 2 Port Valves & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 21: Gas Boiler Wiring Guide

Room T/statRadiators Zone

RadiatorsZone Valve

Greenstar CDi Regular

L NSN LS LR

LZ NZ

External Pump

Double PoleFused Spur

L

EN

L

EN

E

N

L N E 4 5 6 7 8 9 10

M~L

NE

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerSingle Channel

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 22 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi RegularZoned Radiator & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 22: Gas Boiler Wiring Guide

External Pump

C

1 2

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Greenstar CDi Regular

L NSN LS LR

LZ NZ

Double PoleFused Spur

L

EN

L

EN

EL

N

Time ControllerSingle Channel

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 23Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi RegularSingle Hot Water Zone (Vented Cylinder)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 23: Gas Boiler Wiring Guide

External Pump

L N E 4 5 6 7 8 9 10

Greenstar CDi Regular

L NSN LS LR

LZ NZ

Double PoleFused Spur

L

EN

L

EN

EL

N

Time ControllerSingle Channel

N

Room T/Stat

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 24 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi RegularSingle Heating Zone

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 24: Gas Boiler Wiring Guide

Greenstar CDi Regular

L NSN LS LR

LZ NZ

Double PoleFused Spur

L

EN

N

NN

N

CH onCH onHW on

HW onN

N

L3

4

L

L

L

L

L

L

S/L

NO

NO

NO

N/U = Not Used

BOILER

2.5A Fuse - RS Components stock no 415-604

Warning! 240V - Isolate electrical supplybefore removing wiring centre cover.

HW PUMP

CH PUMP

PROGRAMMER

FROST T/STAT

ROOM T/STAT

CYLINDERT/STAT

FUSE2.5A

Frost T/Stat(if required)

Room T/Stat

HW Pump

CHPump

CH/HWProgrammer

CylinderT/Stat

UPP 15-50 PUMP PLAN - WIRING CENTRE CONNECTIONS

(N/U)

(N/U)

(N/U)

1

1

1

2

2

2

(N/U)

N

(N/U)(N/U)

(N/U)

N

N

C

C

Demand

Deman

d

Deman

d

C

P/L

N

L

230V MainsVoltage

Earth terminal for:Controls, Boiler, PumpsElectrical Mains Supply

Page 25Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi RegularGrundfoss Pump Plan

IMPORTANT NOTEThe pump over-run of the pump plan controls, causes the hot water pump to run regardless of thehot water cylinder demand, to dissipate boiler heat. Worcester would only recommend theGrundfoss pump plan system on a vented cylinder.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 25: Gas Boiler Wiring Guide

Greenstar CDi Regular

L NSN LS LR

LZ NZ

MA

INS

BO

ILERPU

MP

SMARTFIT FROSTPROTECTION

ROOM

PORTACCESSORY

S PLAN

A

CHVALVE

(S)CYLINDERSENSOR

SMARTFITROOM UNIT

POLARITYFREE

3 PORTVALVE

(Y)

HWVALVE

(S)

Y PLAN

UNIT

HW VALVE (S)

CH VALVE (S) CYLINDERT/STAT

External Pump

L

EN

N

N

L

Smartfit Layout:Example shown S Plan configurationDouble Pole

Fused Spur

L

EN

L

N

L

SL

PL

230V MainsVoltage

Page 26 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi RegularSmartfit Control Pack

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 26: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Greenstar CDi Regular

Greenstar CDi Regular

L NSN LS LR

LZ NZ

Shunt Pump

Junction Box/Wiring CentreSwitched Live/

DemandN EL

Double PoleFused Spur

L

EN

L

EN

C C

Shunt Pump

L

EN

C

NO

NC

230V ACDouble Pole Relay

Header LimitThermostat

Wiring from Zone/s Controls

Example relay shown is a double pole mains voltage relay. This isolates the boilers electrically in case of a fault condition.

IMPORTANT NOTE:The relay should be mounted within a suitable electrically safe housing.

C C

NC NCNO NO

CoilLive

CoilNeutral

230V MainsVoltage

Page 27Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi RegularCascaded boilers with low loss header

NOTEA pump must be wired to each boiler for pump over-run function to dissipate heat from within theboiler. The connections are pump live to Lz, pump neutral to Nz and pump earth to the Earthpoint of each boiler.

HEADER LIMIT THERMOSTATThis cuts the Demand to the boilers in the event of excessive temperature within the Header dueto lack of circulation. Ideally this should be set to 90ºC.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 27: Gas Boiler Wiring Guide

Greenstar CDi Regular

L NSN LS LR

LZ NZ

Double PoleFused Spur

L

EN

Neutral Feed to Wiring Centre

Earth to Wiring Centre

Live Feed to Wiring Centre

Switch Live from Wiring Centre

FR FS NP LP

Frost T/Stat

L

EN

External Pump

230V MainsVoltage

Page 28 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi RegularFrost Protection

The boiler has inbuilt frost protection. When the primary temperature drops below 8°C the pump is switchedon. When then temperature rises above 9°C the pump switches off after a 3 minute pump overrun. If theprimary temperature drops below 5°C, a central heating demand is activated until the primary temperaturerises above 12 °C. The demand switches off followed by the pump after a 3 minute overrun.

The boiler has the facility to connect an external frost protection device to protect in “at risk areas” (terminalblock ST6, contacts FS and FR). This is used if the boiler is not located in the area needing protection i.e. boilerin kitchen but pipe work in the garage that needs frost protection.

If external frost thermostat is calling, i.e. temperature within frost thermostat below the set point, but theprimary temperature of the boiler is above 5°C, the pump will run until the temperature within the frostthermostat rises above the set point. If external frost thermostat is calling and the primary temperature isbelow 5°C, a central heating demand is activated until primary temperature is above 12 °C. If the frostthermostat is still calling the pump will run until the temperature within the frost thermostat location risesabove the set point.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 28: Gas Boiler Wiring Guide

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Room T/Stat

L

N

Time Controller

HW

ON

CH

ON

M~L

NE

M~L

NE

CylinderZone Valve

HeatingZone Valve

Greenstar CDi System

L NSN LS LR

Double PoleFused Spur

L

EN

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 29Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi System2 x 2 Port Valves (S-Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 29: Gas Boiler Wiring Guide

L NSN LS LR

Double PoleFused Spur

L

EN

CylinderT/Stat

Green/YellowBlueWhiteGreyOrange

EN

Mid PositionValve

L

N

Time Controller

HW

OFF

HW

ON

CH

ON

C

1 2

N

Room T/Stat

L N E 4 5 6 7 8 9 10

Greenstar CDi System

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 30 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi SystemMid Position Valve (Y-Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 30: Gas Boiler Wiring Guide

L NSN LS LR

Double PoleFused Spur

L

EN

CylinderZone Valve

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

HeatingZone 1 Valve

M~L

NE

Room T/StatZone 1

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

Greenstar CDi System

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

CH

Zon

e 2

ON

L

N

Time Controller3 Channel

HW ON

CH Zone 1 ON

Page 31Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi System3 x 2 Port Valves (S-Plan Plus)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 31: Gas Boiler Wiring Guide

Room T/StatZone 1

HeatingZone 1 Valve

L

N

Time Controller

CH

Zon

e 1

ON

CH

Zon

e 2

ON

L NSN LS LR

Double PoleFused Spur

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

Greenstar CDi System

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 32 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi System2 x Heating Zones

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 32: Gas Boiler Wiring Guide

Room T/StatZone 1

HeatingZone 1 ValveL NSN LS LR

Double PoleFused Spur

L

EN

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

M~L

NE

CylinderZone Valve

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerTwin Channel

HW

ON

CH

Zon

e 1

ON

Greenstar CDi System

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 33Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi System2 x 2 Port Valves & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 33: Gas Boiler Wiring Guide

Room T/StatRadiators Zone

RadiatorsZone ValveL NSN LS LR

Double PoleFused Spur

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerSingle Channel

Greenstar CDi System

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 34 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi SystemZoned Radiator & Underfloor

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 34: Gas Boiler Wiring Guide

C

1 2

L N E 4 5 6 7 8 9 10

CylinderT/Stat

L NSN LS LR

Double PoleFused Spur

L

EN

L

N

Time ControllerSingle Channel

Greenstar CDi System

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 35Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi SystemSingle Hot Water Zone (Vented Cylinder)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 35: Gas Boiler Wiring Guide

L N E 4 5 6 7 8 9 10

L NSN LS LR

Double PoleFused Spur

L

EN

L

N

Time ControllerSingle Channel

N

Room T/StatGreenstar

CDi System

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 36 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi SystemSingle Heating Zone

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 36: Gas Boiler Wiring Guide

L NSN LS LR

MA

INS

BO

ILERPU

MP

SMARTFIT FROSTPROTECTION

ROOM

PORTACCESSORY

S PLAN

A

CHVALVE

(S)CYLINDERSENSOR

SMARTFITROOM UNIT

POLARITYFREE

3 PORTVALVE

(Y)

HWVALVE

(S)

Y PLAN

UNIT

HW VALVE (S)

CH VALVE (S) CYLINDERT/STAT

N

N

L

Smartfit Layout:Example shown S Plan configurationDouble Pole

Fused Spur

L

EN

L

N

L

SL

PL

Greenstar CDi System

230V MainsVoltage

Page 37Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi SystemSmartfit Control Pack

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 37: Gas Boiler Wiring Guide

78

9

LNS NLSLR FSFR NP LP

ST10 ST19NOTE:Leave link

NOTE:Leave link

SAFETY LIMITTHERMOSTAT

CYLINDERTHERMOSTAT

230V MAINSSUPPLY

N E L

ST6

ST8

Gre

en\Y

ello

w

Connector Block

(made safe)

Bro

wn

Bro

wn

Blu

e

IMPORTANT NOTE:UNDER NO CIRCUMSTANCES SHOULD THE FEED TO THE LIMIT STAT BE TAKEN THROUGH THE CONTROL STAT.

NOT REQUIREDUSE CYLINDER SENSOR SUPPLIED

LNS NLSLR

FSFR NP LP

BB421AF

BB421AF

78

9

Pump Control

Code Plug

PumpHarness

FanHarness

S112.5 A 230 V AC

Main Harness

S131.6 A

S120.5 A

DIVERTER VALVEMOTOR PLUG

CYLINDER TEMPERATURESENSOR (SUPPLIED IN DIVERTER KIT)

DUAL THERMOSTAT

Page 38 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi SystemInternal Diverter Valve, Worcester RF Controls & Unvented Cylinder

There is a unclarity within the Industry that in order to protect an Unvented Hot Water Cylinder from potentiallydangerous high temperatures from the boiler circuit, a 2-port motorised valve must be installed. This is not thecase, although it is the most common interpretation and approach.

FURTHER DETAILSBuilding Regulation Approved Document G3, paragraph 3.6 states '…the non-self-resetting thermal cut outshould be wired to a motorised valve or some other suitable device to shut off the flow to the primary heater…'.The latter part of this sentence can be interpreted to mean as long as we, as responsible Manufacturer's, areconfident our method provides an equal amount of protection to the common approach, we may instructinstallers of our equipment to follow a different approach. A summary is provided below.

l The installer will use the cylinder sensor supplied with the Integral Diverter Valve kit to control the hot water temperature.

l The installer, therefore, will NOT need to use the hot water control thermostat of the cylinder's dual thermostat.

l The installer may have to alter the wiring of the dual thermostat (depending on cylinder and thermostat manufacturer) to only use the high limit thermal cut-out of the dual thermostat.

l The high limit thermal cut out of the dual thermostat MUST be wired to interrupt the permanent live to the Greenstar CDi System Boiler.

l The 2-port valve supplied with the unvented cylinder will NOT be used. If it is already physically installed in the pipe work is should be removed and electrically disconnected from the wiring centre.

Below you will find an electrical diagram for this arrangement.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 38: Gas Boiler Wiring Guide

78

9

LNS NLSLR FSFR NP LP

ST10 ST19NOTE:Leave link

NOTE:Leave link

SAFETY LIMITTHERMOSTAT

CYLINDERTHERMOSTAT

230V MAINSSUPPLY

N E L

ST6

ST8

Gre

en\Y

ello

w

Connector Block

(made safe)

Bro

wn

Bro

wn

Blu

e

IMPORTANT NOTE:UNDER NO CIRCUMSTANCES SHOULD THE FEED TO THE LIMIT STAT BE TAKEN THROUGH THE CONTROL STAT.

NOT REQUIREDUSE CYLINDER SENSOR SUPPLIED

LNS NLSLR

FSFR NP LP

BB421AF

BB

BB421AF

AF

78

9

Pump Control

Code Plug

PumpHarness

FanHarness

S112.5 A 230 V AC

Main Harness

S131.6 A

S120.5 A

DIVERTER VALVEMOTOR PLUG

FW 100CONTROLLER

OUTSIDESENSOR

CYLINDER TEMPERATURESENSOR (SUPPLIED IN DIVERTER KIT)

DUAL THERMOSTAT

Page 39Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi SystemInternal Diverter Valve, Worcester FX Controls & Unvented Cylinder

There is a unclarity within the Industry that in order to protect an Unvented Hot Water Cylinder from potentiallydangerous high temperatures from the boiler circuit, a 2-port motorised valve must be installed. This is not thecase, although it is the most common interpretation and approach.

FURTHER DETAILSBuilding Regulation Approved Document G3, paragraph 3.6 states '…the non-self-resetting thermal cut outshould be wired to a motorised valve or some other suitable device to shut off the flow to the primary heater…'.The latter part of this sentence can be interpreted to mean as long as we, as responsible Manufacturer's, areconfident our method provides an equal amount of protection to the common approach, we may instructinstallers of our equipment to follow a different approach. A summary is provided below.

l The installer will use the cylinder sensor supplied with the Integral Diverter Valve kit to control the hot water temperature.

l The installer, therefore, will NOT need to use the hot water control thermostat of the cylinder's dual thermostat.

l The installer may have to alter the wiring of the dual thermostat (depending on cylinder and thermostat manufacturer) to only use the high limit thermal cut-out of the dual thermostat.

l The high limit thermal cut out of the dual thermostat MUST be wired to interrupt the permanent live to the Greenstar CDi System Boiler.

l The 2-port valve supplied with the unvented cylinder will NOT be used. If it is already physically installed in the pipe work is should be removed and electrically disconnected from the wiring centre.

Below you will find an electrical diagram for this arrangement.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 39: Gas Boiler Wiring Guide

L NSN LS LRL NSN LS LR

Junction Box/Wiring CentreSwitched Live/

DemandN EL

Double PoleFused Spur

L

EN

C C

C

NO

NC

230V ACDouble Pole Relay

Header LimitThermostat

Wiring from Zone/s Controls

Example relay shown is a Double Pole Mains Voltage Relay. This isolates the Boilers electrically in case of a fault condition.

IMPORTANT NOTE:The Relay should be mounted within a suitable electrically safe housing.

C C

NC NCNO NO

CoilLive

CoilNeutral

Greenstar CDi System

Greenstar CDi System

230V MainsVoltage

Page 40 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi SystemCascaded boilers with low loss header

HEADER LIMIT THERMOSTATThis cuts the Demand to the boilers in the event of excessive temperature within the Header dueto lack of circulation. Ideally this should be set to 90º C.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 40: Gas Boiler Wiring Guide

Greenstar CDi System

L NSN LS LR

Double PoleFused Spur

L

EN

Neutral Feed to Wiring Centre

Earth to Wiring Centre

Live Feed to Wiring Centre

Switch Live from Wiring Centre

FR FS NP LP

Frost T/Stat

230V MainsVoltage

Page 41Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi SystemFrost Protection

The boiler has inbuilt frost protection. When the primary temperature drops below 8°C the pump is switchedon. When then temperature rises above 9°C the pump switches off after a 3 minute pump overrun. If theprimary temperature drops below 5°C, a central heating demand is activated until the primary temperaturerises above 12 °C. The demand switches off followed by the pump after a 3 minute overrun.

The boiler has the facility to connect an external frost protection device to protect in “at risk areas” (terminalblock ST6, contacts FS and FR). This is used if the boiler is not located in the area needing protection i.e. boilerin kitchen but pipe work in the garage that needs frost protection.

If external frost thermostat is calling, i.e. temperature within frost thermostat below the set point, but theprimary temperature of the boiler is above 5°C, the pump will run until the temperature within the frostthermostat rises above the set point. If external frost thermostat is calling and the primary temperature isbelow 5°C, a central heating demand is activated until primary temperature is above 12 °C. If the frostthermostat is still calling the pump will run until the temperature within the frost thermostat location risesabove the set point.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 41: Gas Boiler Wiring Guide

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Room T/Stat

L

N

Time Controller

HW

ON

CH

ON

M~L

NE

M~L

NE

CylinderZone Valve

HeatingZone Valve

Greenstar CDi Combi

L NSN LS LR

Double PoleFused Spur

L

EN

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 42 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi Combi2 x 2 Port Valves (S-Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 42: Gas Boiler Wiring Guide

L NSN LS LR

Double PoleFused Spur

L

EN

CylinderT/Stat

Green/YellowBlueWhiteGreyOrange

EN

Mid PositionValve

L

N

Time Controller

HW

OFF

HW

ON

CH

ON

C

1 2

N

Room T/Stat

L N E 4 5 6 7 8 9 10

Greenstar CDi Combi

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 43Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi CombiMid Position Valve (Y-Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 43: Gas Boiler Wiring Guide

L NSN LS LR

Double PoleFused Spur

L

EN

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

HeatingZone 1 Valve

M~L

NE

Room T/StatZone 1

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

CylinderZone Valve

Greenstar CDi Combi

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

CH

Zon

e 2

ON

L

N

Time Controller3 Channel

HW ON

CH Zone 1 ON

Page 44 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi combi3 x 2 Port Valves (S-Plan Plus)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 44: Gas Boiler Wiring Guide

Room T/StatZone 1

HeatingZone 1 Valve

L

N

Time Controller

CH

Zon

e 1

ON

CH

Zon

e 2

ON

L NSN LS LR

Double PoleFused Spur

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

Greenstar CDi Combi

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 45Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi combi2 x Heating Zones

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 45: Gas Boiler Wiring Guide

Room T/StatZone 1

HeatingZone 1 ValveL NSN LS LR

Double PoleFused Spur

L

EN

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

M~L

NE

CylinderZone Valve

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerTwin Channel

HW

ON

CH

Zon

e 1

ON

Greenstar CDi Combi

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 46 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi Combi2 x 2 Port Valves & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 46: Gas Boiler Wiring Guide

Room T/StatRadiators Zone

RadiatorsZone ValveL NSN LS LR

Double PoleFused Spur

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerSingle Channel

Greenstar CDi Combi

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 47Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi CombiZoned Radiator & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 47: Gas Boiler Wiring Guide

L NSN LS LR

Double PoleFused Spur

L

EN

Room T/Stat

Time Controller

Series ConnectorNot supplied. Once wired in make connector safe in electrical cover.

Greenstar CDi Combi

230V MainsVoltage

Page 48 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi Combiseparate Time Controller & Room Thermostat

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 48: Gas Boiler Wiring Guide

L NSN LS LR

The Link between the Live (L) and Common (C) may already be fitted as

part of the Programmable Thermostat, if not then a link must be fitted.

Double PoleFused Spur

L

EN

Greenstar CDi Combi

ProgrammableThermostat

N L NC NOC

230V MainsVoltage

Page 49Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi CombiProgrammable Thermostat

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 49: Gas Boiler Wiring Guide

L NSN LS LR

MA

INS

BO

ILERPU

MP

SMARTFIT FROSTPROTECTION

ROOM

PORTACCESSORY

S PLAN

A

CHVALVE

(S)CYLINDERSENSOR

SMARTFITROOM UNIT

POLARITYFREE

3 PORTVALVE

(Y)

HWVALVE

(S)

Y PLAN

UNIT

HW VALVE (S)

CH VALVE (S) CYLINDERT/STAT

N

N

L

Smartfit Layout:Example shown S Plan configurationDouble Pole

Fused Spur

L

EN

L

N

L

SL

PL

Greenstar CDi Combi

230V MainsVoltage

Page 50 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi CombiSmartfit Control Pack

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 50: Gas Boiler Wiring Guide

L NSN LS LRL NSN LS LR

Junction Box/Wiring CentreSwitched Live/

DemandN EL

Double PoleFused Spur

L

EN

C C

C

NO

NC

230V ACDouble Pole Relay

Header LimitThermostat

Wiring from Zone/s Controls

Example relay shown is a Double Pole Mains Voltage Relay. This isolates the Boilers electrically in case of a fault condition.

IMPORTANT NOTE:The Relay should be mounted within a suitable electrically safe housing.

C C

NC NCNO NO

CoilLive

CoilNeutral

Greenstar CDi Combi

Greenstar CDi Combi

230V MainsVoltage

Page 51Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi CombiCascade boilers with low loss header

NOTEA pump must be wired to each boiler for pump over-run to dissipate heat from within the boiler.The connections are pump live to Lz, pump neutral to Nz and pump earth to the Earth point ofeach boiler.

HEADER LIMIT THERMOSTATThis cuts the Demand to the boilers in the event of excessive temperature within the Header dueto lack of circulation. Ideally this should be set to 90ºC.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 51: Gas Boiler Wiring Guide

Greenstar CDi Combi

L NSN LS LR

Double PoleFused Spur

L

EN

FR FS NP LP

Frost T/Stat

230V MainsVoltage

Page 52 Worcester wiring guide Greenstar gas-fired boilers

Greenstar CDi CombiFrost Protection

The boiler has inbuilt frost protection. When the primary temperature drops below 8°C the pump is switchedon. When then temperature rises above 9°C the pump switches off after a 3 minute pump overrun. If theprimary temperature drops below 5°C, a central heating demand is activated until the primary temperaturerises above 12 °C. The demand switches off followed by the pump after a 3 minute overrun.

The boiler has the facility to connect an external frost protection device to protect in “at risk areas” (terminalblock ST6, contacts FS and FR). This is used if the boiler is not located in the area needing protection i.e. boilerin kitchen but pipe work in the garage that needs frost protection.

If external frost thermostat is calling, i.e. temperature within frost thermostat below the set point, but theprimary temperature of the boiler is above 5°C, the pump will run until the temperature within the frostthermostat rises above the set point. If external frost thermostat is calling and the primary temperature isbelow 5°C, a central heating demand is activated until primary temperature is above 12 °C. If the frostthermostat is still calling the pump will run until the temperature within the frost thermostat location risesabove the set point.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 52: Gas Boiler Wiring Guide

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Room T/Stat

L

N

Time Controller

HW

ON

CH

ON

M~L

NE

M~L

NE

CylinderZone Valve

HeatingZone Valve

L NSN LS LR

LZ NZ

Double PoleFused Spur

L

EN

L

EN

External Pump

Greenstar FS CDi Regular

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 53Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi Regular2 x 2 Port Valves (S Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 53: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Double PoleFused Spur

L

EN

L

EN

CylinderT/Stat

Green/YellowBlueWhiteGreyOrange

EN

Mid PositionValve

L

N

Time Controller

HW

OFF

HW

ON

CH

ON

C

1 2

N

Room T/Stat

L N E 4 5 6 7 8 9 10

External Pump

Greenstar FS CDi Regular L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 54 Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi RegularMid Position Valve (Y Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 54: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Greenstar FS CDi Regular

External Pump

Double PoleFused Spur

L

EN

L

EN

CylinderZone Valve

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

HeatingZone 1 Valve

M~L

NE

Room T/StatZone 1

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

CH

Zon

e 2

ON

L

N

Time Controller3 Channel

HW ON

CH Zone 1 ON

Page 55Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi Regular3 x 2 Port Valves (S Plan Plus)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 55: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Greenstar FS CDi Regular

Room T/StatZone 1

HeatingZone 1 Valve

L

N

Time Controller

CH

Zon

e 1

ON

CH

Zon

e 2

ON

Double PoleFused Spur

L

EN

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

External Pump

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 56 Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi Regular2 x Heating Zones

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 56: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Greenstar FS CDi Regular

Room T/StatZone 1

HeatingZone 1 Valve

Double PoleFused Spur

L

EN

L

EN

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

M~L

NE

CylinderZone Valve

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerTwin Channel

HW

ON

CH

Zon

e 1

ON

External Pump

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 57Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi Regular2 x 2 Port Valves & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 57: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Greenstar FS CDi Regular

Room T/StatRadiators Zone

RadiatorsZone Valve

External Pump

Double PoleFused Spur

L

EN

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerSingle Channel

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 58 Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi RegularZoned Radiator & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 58: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Greenstar FS CDi Regular

External Pump

C

1 2

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Double PoleFused Spur

L

EN

L

EN

L

N

Time ControllerSingle Channel

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 59Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi RegularSingle Hot Water Zone (Vented Cylinder)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 59: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Greenstar FS CDi Regular

External Pump

L N E 4 5 6 7 8 9 10Double PoleFused Spur

L

EN

L

EN

L

N

Time ControllerSingle Channel

N

Room T/Stat

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 60 Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi RegularSingle Heating Zone

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 60: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Greenstar FS CDi Regular

Double PoleFused Spur

L

EN

N

NN

N

CH onCH onHW on

HW onN

N

L3

4

L

L

L

L

L

L

S/L

NO

NO

NO

N/U = Not Used

BOILER

2.5A Fuse - RS Components stock no 415-604

Warning! 240V - Isolate electrical supplybefore removing wiring centre cover.

HW PUMP

CH PUMP

PROGRAMMER

FROST T/STAT

ROOM T/STAT

CYLINDERT/STAT

FUSE2.5A

Frost T/Stat(if required)

Room T/Stat

HW Pump

CHPump

CH/HWProgrammer

Cylinder T/Stat

UPP 15-50 PUMP PLAN - WIRING CENTRE CONNECTIONS

(N/U)

(N/U)

(N/U)

1

1

1

2

2

2

(N/U)

N

(N/U)(N/U)

(N/U)

N

N

C

C

Demand

Deman

d

Deman

d

C

P/L

N

L

230V MainsVoltage

Page 61Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi RegularGrundfoss Pump Plan

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

IMPORTANT NOTEThe pump over-run of the pump plan controls, causes the hot water pump to run regardless of thehot water cylinder demand, to dissipate boiler heat. Worcester would only recommend theGrundfoss pump plan system on a vented cylinder.

Page 61: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Greenstar FS CDi Regular

MA

INS

BO

ILERPU

MP

SMARTFIT FROSTPROTECTION

ROOM

PORTACCESSORY

S PLAN

A

CHVALVE

(S)CYLINDERSENSOR

SMARTFITROOM UNIT

POLARITYFREE

3 PORTVALVE

(Y)

HWVALVE

(S)

Y PLAN

UNIT

HW VALVE (S)

CH VALVE (S) CYLINDERT/STAT

External Pump

L

EN

N

N

L

Smartfit Layout:Example shown S Plan configurationDouble Pole

Fused Spur

L

EN

L

N

L

SL

PL

230V MainsVoltage

Page 62 Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi RegularSmartfit Control Pack

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 62: Gas Boiler Wiring Guide

L NSN LS LR

LZ NZ

Greenstar FS CDi Regular

L NSN LS LR

LZ NZ

Greenstar FS CDi Regular

Shunt Pump

Junction Box/Wiring CentreSwitched Live/

DemandN EL

Double PoleFused Spur

L

EN

L

EN

C C

Shunt Pump

L

EN

C

NO

NC

230V ACDouble Pole Relay

Header LimitThermostat

Wiring from Zone/s Controls

Example relay shown is a Double Pole Mains Voltage Relay. This isolates the Boilers electrically in case of a fault condition.

IMPORTANT NOTE:The Relay should be mounted within a suitable electrically safe housing.

C C

NC NCNO NO

CoilLive

CoilNeutral

230V MainsVoltage

Page 63Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi RegularCascaded boilers with low loss header

NOTEA pump must be wired to each boiler for pump over-run to dissipate heat from within the boiler.The connections are pump live to Lz, pump neutral to Nz and pump earth to the Earth point ofeach boiler.

HEADER LIMIT THERMOSTATThis cuts the Demand to the boilers in the event of excessive temperature within the Header dueto lack of circulation. Ideally this should be set to 90ºC.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 63: Gas Boiler Wiring Guide

L NSN LS LR

Greenstar FS CDi Regular

Double PoleFused Spur

L

EN Neutral Feed to Wiring Centre

Earth to Wiring Centre

Live Feed to Wiring Centre

Switch Live from Wiring Centre

LZ NZ

L

EN

E

External Pump

FR FS NP LP

Frost Stat

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 64 Worcester wiring guide Greenstar gas-fired boilers

Greenstar FS CDi RegularFrost Protection

The boiler has inbuilt frost protection. When the primary temperature drops below 8°C the pump is switchedon. When then temperature rises above 9°C the pump switches off after a 3 minute pump overrun. If theprimary temperature drops below 5°C, a central heating demand is activated until the primary temperaturerises above 12 °C. The demand switches off followed by the pump after a 3 minute overrun.

The boiler has the facility to connect an external frost protection device to protect in “at risk areas” (terminalblock ST6, contacts FS and FR). This is used if the boiler is not located in the area needing protection i.e. boilerin kitchen but pipe work in the garage that needs frost protection.

If external frost thermostat is calling, i.e. temperature within frost thermostat below the set point, but theprimary temperature of the boiler is above 5°C, the pump will run until the temperature within the frostthermostat rises above the set point. If external frost thermostat is calling and the primary temperature isbelow 5°C, a central heating demand is activated until primary temperature is above 12 °C. If the frostthermostat is still calling the pump will run until the temperature within the frost thermostat location risesabove the set point.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 64: Gas Boiler Wiring Guide

Greenstar HF CDi

L NSN LS LR

NC

Safety isolation

230V HW interface‘Installer Module’

Room T/StatZone 1

HeatingZone 1 Valve

N

L N E 4 5 6 7 8 9 10

M~L

NE

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

N

Double PoleFused Spur

L

EN

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

CH

Zon

e 2

ON

L

N

Time Controller3 Channel

HW ON

CH

Zon

e 1

ON

Page 65Worcester wiring guide Greenstar gas-fired boilers

Greenstar HF CDi combi2 x Heating Zones

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 65: Gas Boiler Wiring Guide

Room T/StatRadiators Zone

RadiatorsZone Valve

N

L N E 4 5 6 7 8 9 10

M~L

NE

Underfloor ControlsWiring Centre

ENL

L N E Demand

Greenstar HF CDi

L NSN LS LR

NC

Safety isolation

230V HW interface‘Installer Module’

N

Double PoleFused Spur

L

EN

L

N

Time Controller

HW Heat Bank ON

CH

Rad

s O

N

L

N

E

= Live

= Neutral

= EarthE

N

L

ENL

230V MainsVoltage

Page 66 Worcester wiring guide Greenstar gas-fired boilers

Greenstar HF CDi combiZoned Radiator & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 66: Gas Boiler Wiring Guide

Room T/Stat

Series ConnectorNot supplied. Once wired in make connector safe in electrical cover.

Greenstar HF CDi

L NSN LS LR

NC

Safety isolation

230V HW interface‘Installer Module’

N

Time Controller

HW Heat Bank ON

CH

ON

Double PoleFused Spur

L

EN

230V MainsVoltage

Page 67Worcester wiring guide Greenstar gas-fired boilers

Greenstar HF CDi combiseparate Time Controller & Room Thermostat

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 67: Gas Boiler Wiring Guide

Greenstar HF CDi

L NSN LS LR

NC

Safety isolation

230V HW interface‘Installer Module’

N

HW

Hea

t Ban

k O

N

Double PoleFused Spur

L

EN

ProgrammableThermostat

N L NC NOC

Time ControllerHot Water Heat Bank

The Link between the Live (L) and Common (C) may already be fitted as

part of the Programmable Thermostat, if not then a link must be wired in.

230V MainsVoltage

Page 68 Worcester wiring guide Greenstar gas-fired boilers

Greenstar HF CDi combiProgrammable Thermostat

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 68: Gas Boiler Wiring Guide

Greenstar HF CDi

L NSN LS LR

NC

Safety isolation

230V HW interface‘Installer Module’

C

NO

NC

Header LimitThermostat

Room T/Stat

N

Time Controller

HW Heat Bank ON

CH

ON

Double PoleFused Spur

L

EN

SystemPump

L

EN

E

L N E 4 5 6 7 8 9 10

L

N

E

= Live

= Neutral

= EarthE

N

L

E

230V MainsVoltage

Page 69Worcester wiring guide Greenstar gas-fired boilers

Greenstar HF CDi combiLarge heating circuit with low loss header

If the heating system requires a larger pump to circulate the water, then a header can be used toprevent the boiler and system pump from conflicting with each other.

NOTEThe system pump is wired with the heating demand so it will only activate when the heating iscalled for. Size the system pump according to system design specifications and water content.

HEADER LIMIT THERMOSTATThis cuts the Demand to the boiler in the event of excessive temperature within the header due tolack of circulation. Ideally this should be set to 90ºC.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 69: Gas Boiler Wiring Guide

Double PoleFused Spur

L

EN

Greenstar HF CDi

L NSN LS LR

NC

Safety isolation

230V HW interface‘Installer Module’

N

FR FS NP LP

Frost T/Stat

230V MainsVoltage

Page 70 Worcester wiring guide Greenstar gas-fired boilers

Greenstar HF CDi combiFrost Protection

The boiler has inbuilt frost protection. When the primary temperature drops below 8°C the pump is switchedon. When then temperature rises above 9°C the pump switches off after a 3 minute pump overrun. If theprimary temperature drops below 5°C, a central heating demand is activated until the primary temperaturerises above 12 °C. The demand switches off followed by the pump after a 3 minute overrun.

The boiler has the facility to connect an external frost protection device to protect in “at risk areas” (terminalblock ST6, contacts FS and FR). This is used if the boiler is not located in the area needing protection i.e. boilerin kitchen but pipe work in the garage that needs frost protection.

If external frost thermostat is calling, i.e. temperature within frost thermostat below the set point, but theprimary temperature of the boiler is above 5°C, the pump will run until the temperature within the frostthermostat rises above the set point. If external frost thermostat is calling and the primary temperature isbelow 5°C, a central heating demand is activated until primary temperature is above 12 °C. If the frostthermostat is still calling the pump will run until the temperature within the frost thermostat location risesabove the set point.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 70: Gas Boiler Wiring Guide

GreenstarSi Combi

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Room T/Stat

L

N

Time Controller

HW

ON

CH

ON

M~L

NE

M~L

NE

CylinderZone Valve

HeatingZone ValveL NSN LS LR

Double PoleFused Spur

L

EN

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 71Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si Combi2 x 2 Port Valves (S Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 71: Gas Boiler Wiring Guide

GreenstarSi Combi

L NSN LS LR

Double PoleFused Spur

L

EN

CylinderT/Stat

Green/YellowBlueWhiteGreyOrange

EN

Mid PositionValve

L

N

Time Controller

HW

OFF

HW

ON

CH

ON

C

1 2

N

Room T/Stat

L N E 4 5 6 7 8 9 10

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 72 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si CombiMid Position Valve (Y Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 72: Gas Boiler Wiring Guide

GreenstarSi Combi

L NSN LS LR

Double PoleFused Spur

L

EN

CylinderZone Valve

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

HeatingZone 1 Valve

M~L

NE

Room T/StatZone 1

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

CH

Zon

e 2

ON

L

N

Time Controller3 Channel

HW ON

CH Zone 1 ON

Page 73Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si Combi3 x 2 Port Valves (S Plan Plus)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 73: Gas Boiler Wiring Guide

GreenstarSi Combi Room T/Stat

Zone 1

HeatingZone 1 Valve

L

N

Time Controller

CH

Zon

e 1

ON

CH

Zon

e 2

ON

L NSN LS LR

Double PoleFused Spur

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 74 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si Combi2 x Heating Zones

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 74: Gas Boiler Wiring Guide

GreenstarSi Combi

Room T/StatZone 1

HeatingZone 1 ValveL NSN LS LR

Double PoleFused Spur

L

EN

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

M~L

NE

CylinderZone Valve

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerTwin Channel

HW

ON

CH

Zon

e 1

ON

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 75Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si Combi2 x 2 Port Valves & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 75: Gas Boiler Wiring Guide

GreenstarSi Combi Room T/Stat

Radiators Zone

RadiatorsZone ValveL NSN LS LR

Double PoleFused Spur

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerSingle Channel

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

CH

ON

Page 76 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si CombiZoned Radiator & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 76: Gas Boiler Wiring Guide

GreenstarSi Combi

L NSN LS LR

Double PoleFused Spur

L

EN

Room T/Stat

Time Controller

Series ConnectorNot supplied. Once wired in, make connector safe in electrical cover.

230V MainsVoltage

CH

ON

Page 77Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si Combiseparate Time Controller & Room Thermostat

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 77: Gas Boiler Wiring Guide

GreenstarSi Combi

L NSN LS LR

Double PoleFused Spur

L

EN

ProgrammableThermostat

N L NC NOC

The Link between the Live (L) and Common (C) may already be fitted as

part of the Programmable Thermostat, if not then a link must be wired in.

230V MainsVoltage

Page 78 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si CombiProgrammable Thermostat

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 78: Gas Boiler Wiring Guide

GreenstarSi Combi

L NSN LS LR

MA

INS

BO

ILERPU

MP

SMARTFIT FROSTPROTECTION

ROOM

PORTACCESSORY

S PLAN

A

CHVALVE

(S)CYLINDERSENSOR

SMARTFITROOM UNIT

POLARITYFREE

3 PORTVALVE

(Y)

HWVALVE

(S)

Y PLAN

UNIT

HW VALVE (S)

CH VALVE (S) CYLINDERT/STAT

N

N

L

Smartfit Layout:Example shown S Plan configurationDouble Pole

Fused Spur

L

EN

L

N

L

SL

PL

230V MainsVoltage

Page 79Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si CombiSmartfit Control Pack

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 79: Gas Boiler Wiring Guide

GreenstarSi Combi

GreenstarSi Combi

L NSN LS LRL NSN LS LR

Junction Box/Wiring CentreSwitched Live/

DemandN EL

Double PoleFused Spur

L

EN

C C

C

NO

NC

230V ACDouble Pole Relay

Header LimitThermostat

Wiring from Zone/s Controls

Example relay shown is a Double Pole Mains Voltage Relay. This isolates the Boilers electrically in case of a fault condition.

IMPORTANT NOTE:The Relay should be mounted within a suitable electrically safe housing.

C C

NC NCNO NO

CoilLive

CoilNeutral

230V MainsVoltage

Page 80 Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si CombiCascaded boilers with low loss header

HEADER LIMIT THERMOSTATThis cuts the Demand to the boilers in the event of excessive temperature within the Headerdue to lack of circulation. Ideally this should be set to 90º C.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 80: Gas Boiler Wiring Guide

GreenstarSi Combi

L NSN LS LR

Double PoleFused Spur

L

EN

FR FS NP LP

Frost T/Stat

230V MainsVoltage

Page 81Worcester wiring guide Greenstar gas-fired boilers

Greenstar Si CombiFrost Protection

The boiler has inbuilt frost protection. When the primary temperature drops below 8°C the pump is switchedon. When then temperature rises above 9°C the pump switches off after a 3 minute pump overrun. If theprimary temperature drops below 5°C, a central heating demand is activated until the primary temperaturerises above 12 °C. The demand switches off followed by the pump after a 3 minute overrun.

The boiler has the facility to connect an external frost protection device to protect in “at risk areas” (terminalblock ST6, contacts FS and FR). This is used if the boiler is not located in the area needing protection i.e. boilerin kitchen but pipe work in the garage that needs frost protection.

If external frost thermostat is calling, i.e. temperature within frost thermostat below the set point, but theprimary temperature of the boiler is above 5°C, the pump will run until the temperature within the frostthermostat rises above the set point. If external frost thermostat is calling and the primary temperature isbelow 5°C, a central heating demand is activated until primary temperature is above 12 °C. If the frostthermostat is still calling the pump will run until the temperature within the frost thermostat location risesabove the set point.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 81: Gas Boiler Wiring Guide

Greenstari Jnr Combi

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Room T/Stat

L

N

Time Controller

HW

ON

CH

ON

M~L

NE

M~L

NE

CylinderZone Valve

HeatingZone ValveL NSN LS LR

Double PoleFused Spur

L

EN

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 82 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior Combi2 x 2 Port Valves (S Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 82: Gas Boiler Wiring Guide

Greenstari Jnr Combi

L NSN LS LR

Double PoleFused Spur

L

EN

CylinderT/Stat

Green/YellowBlueWhiteGreyOrange

EN

Mid PositionValve

L

N

Time Controller

HW

OFF

HW

ON

CH

ON

C

1 2

N

Room T/Stat

L N E 4 5 6 7 8 9 10

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 83Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior CombiMid Position Valve (Y Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 83: Gas Boiler Wiring Guide

Greenstari Jnr Combi

L NSN LS LR

Double PoleFused Spur

L

EN

CylinderZone Valve

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

HeatingZone 1 Valve

M~L

NE

Room T/StatZone 1

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

CH

Zon

e 2

ON

L

N

Time Controller3 Channel

HW ON

CH Zone 1 ON

Page 84 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior Combi3 x 2 Port Valves (S Plan Plus)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 84: Gas Boiler Wiring Guide

Greenstari Jnr Combi Room T/Stat

Zone 1

HeatingZone 1 Valve

L

N

Time Controller

CH

Zon

e 1

ON

CH

Zon

e 2

ON

L NSN LS LR

Double PoleFused Spur

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 85Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior Combi2 x Heating Zones

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 85: Gas Boiler Wiring Guide

Greenstari Jnr Combi

Room T/StatZone 1

HeatingZone 1 ValveL NSN LS LR

Double PoleFused Spur

L

EN

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

M~L

NE

CylinderZone Valve

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerTwin Channel

HW

ON

CH

Zon

e 1

ON

ENL

L

N

E

= Live

= Neurtal

= EarthE

N

L

230V MainsVoltage

Page 86 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior Combi2 x 2 Port Valves & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 86: Gas Boiler Wiring Guide

Greenstari Jnr Combi Room T/Stat

Radiators Zone

RadiatorsZone ValveL NSN LS LR

Double PoleFused Spur

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerSingle Channel

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

CH

ON

Page 87Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior CombiZoned Radiator & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 87: Gas Boiler Wiring Guide

Greenstari Jnr Combi

L NSN LS LR

Double PoleFused Spur

L

EN

Room T/Stat

Time Controller

Series ConnectorNot supplied. Once wired in, make connector safe in electrical cover.

230V MainsVoltage

CH

ON

Page 88 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior Combiseparate Time Controller & Room Thermostat

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 88: Gas Boiler Wiring Guide

Greenstari Jnr Combi

L NSN LS LR

Double PoleFused Spur

L

EN

ProgrammableThermostat

N L NC NOC

The Link between the Live (L) and Common (C) may already be fitted as

part of the Programmable Thermostat, if not then a link must be wired in.

230V MainsVoltage

Page 89Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior CombiProgrammable Thermostat

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 89: Gas Boiler Wiring Guide

Greenstari Jnr Combi

L NSN LS LR

MA

INS

BO

ILERPU

MP

SMARTFIT FROSTPROTECTION

ROOM

PORTACCESSORY

S PLAN

A

CHVALVE

(S)CYLINDERSENSOR

SMARTFITROOM UNIT

POLARITYFREE

3 PORTVALVE

(Y)

HWVALVE

(S)

Y PLAN

UNIT

HW VALVE (S)

CH VALVE (S) CYLINDERT/STAT

N

N

L

Smartfit Layout:Example shown S Plan configurationDouble Pole

Fused Spur

L

EN

L

N

L

SL

PL

230V MainsVoltage

Page 90 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior combiSmartfit Control Pack

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 90: Gas Boiler Wiring Guide

Greenstari Jnr Combi

Greenstari jnr Combi

L NSN LS LRL NSN LS LR

Junction Box/Wiring CentreSwitched Live/

DemandN EL

Double PoleFused Spur

L

EN

C C

C

NO

NC

230V ACDouble Pole Relay

Header LimitThermostat

Wiring from Zone/s Controls

Example relay shown is a Double Pole Mains Voltage Relay. This isolates the Boilers electrically in case of a fault condition.

IMPORTANT NOTE:The Relay should be mounted within a suitable electrically safe housing.

C C

NC NCNO NO

CoilLive

CoilNeutral

230V MainsVoltage

Page 91Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior combiCascade boilers with low loss header

HEADER LIMIT THERMOSTATThis cuts the Demand to the boilers in the event of excessive temperature within the Header dueto lack of circulation. Ideally this should be set to 90º C.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 91: Gas Boiler Wiring Guide

Greenstari Jnr Combi

L NSN LS LR

Double PoleFused Spur

L

EN

FR FS NP LP

Frost T/Stat

230V MainsVoltage

Page 92 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i Junior combiFrost Protection

The boiler has inbuilt frost protection. When the primary temperature drops below 8°C the pump is switchedon. When then temperature rises above 9°C the pump switches off after a 3 minute pump overrun. If theprimary temperature drops below 5°C, a central heating demand is activated until the primary temperaturerises above 12 °C. The demand switches off followed by the pump after a 3 minute overrun.

The boiler has the facility to connect an external frost protection device to protect in “at risk areas” (terminalblock ST6, contacts FS and FR). This is used if the boiler is not located in the area needing protection i.e. boilerin kitchen but pipe work in the garage that needs frost protection.

If external frost thermostat is calling, i.e. temperature within frost thermostat below the set point, but theprimary temperature of the boiler is above 5°C, the pump will run until the temperature within the frostthermostat rises above the set point. If external frost thermostat is calling and the primary temperature isbelow 5°C, a central heating demand is activated until primary temperature is above 12 °C. If the frostthermostat is still calling the pump will run until the temperature within the frost thermostat location risesabove the set point.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 92: Gas Boiler Wiring Guide

Greenstari System

L NSN LS LR C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Room T/Stat

L

N

Time Controller

HW

ON

CH

ON

M~L

NE

M~L

NE

CylinderZone Valve

HeatingZone Valve

Double PoleFused Spur

L

EN

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 93Worcester wiring guide Greenstar gas-fired boilers

Greenstar i System2 x 2 Port Valves (S Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 93: Gas Boiler Wiring Guide

Greenstari System

L NSN LS LR

Double PoleFused Spur

L

EN

CylinderT/Stat

Green/YellowBlueWhiteGreyOrange

EN

Mid PositionValve

L

N

Time Controller

HW

OFF

HW

ON

CH

ON

C

1 2

N

Room T/Stat

L N E 4 5 6 7 8 9 10

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 94 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i SystemMid Position Valve (Y Plan)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 94: Gas Boiler Wiring Guide

Greenstari System

L NSN LS LR

Double PoleFused Spur

L

EN

CylinderZone Valve

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

HeatingZone 1 Valve

M~L

NE

Room T/StatZone 1

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

CH

Zon

e 2

ON

L

N

Time Controller3 Channel

HW ON

CH Zone 1 ON

Page 95Worcester wiring guide Greenstar gas-fired boilers

Greenstar i System3 x 2 Port Valves (S Plan Plus)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 95: Gas Boiler Wiring Guide

Greenstari System

L NSN LS LR

Room T/StatZone 1

HeatingZone 1 Valve

L

N

Time Controller

CH

Zon

e 1

ON

CH

Zon

e 2

ON

Double PoleFused Spur

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

M~L

NE

HeatingZone 2 Valve

N

Room T/StatZone 2

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 96 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i System2 x Heating Zones

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 96: Gas Boiler Wiring Guide

Greenstari System

L NSN LS LR

Room T/StatZone 1

HeatingZone 1 Valve

Double PoleFused Spur

L

EN

C

1 2

N

L N E 4 5 6 7 8 9 10

CylinderT/Stat

M~L

NE

M~L

NE

CylinderZone Valve

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

N

Time ControllerTwin Channel

HW

ON

CH

Zon

e 1

ON

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 97Worcester wiring guide Greenstar gas-fired boilers

Greenstar i System2 x 2 Port Valves & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 97: Gas Boiler Wiring Guide

Greenstari System

L NSN LS LR

Room T/StatRadiators Zone

RadiatorsZone Valve

Double PoleFused Spur

L

EN

N

L N E 4 5 6 7 8 9 10

M~L

NE

Underfloor ControlsWiring Centre

ENL

L N E Demand

L

NE

= Live

= Neurtal= Earth

L

N

Time ControllerSingle Channel

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

CH

ON

Page 98 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i SystemZoned Radiator & Underfloor Heating

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 98: Gas Boiler Wiring Guide

Greenstari System

L NSN LS LR

C

1 2

L N E 4 5 6 7 8 9 10

CylinderT/Stat

Double PoleFused Spur

L

EN

L

N

Time ControllerSingle Channel

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 99Worcester wiring guide Greenstar gas-fired boilers

Greenstar i SystemSingle Hot Water Zone (Vented Cylinder)

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 99: Gas Boiler Wiring Guide

Greenstari System

L NSN LS LR

L N E 4 5 6 7 8 9 10Double PoleFused Spur

L

EN

L

N

Time ControllerSingle Channel

N

Room T/Stat

ENL

L

N

E

= Live

= Neutral

= EarthE

N

L

230V MainsVoltage

Page 100 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i SystemSingle Heating Zone

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 100: Gas Boiler Wiring Guide

Greenstari System

L NSN LS LR

MA

INS

BO

ILERPU

MP

SMARTFIT FROSTPROTECTION

ROOM

PORTACCESSORY

S PLAN

A

CHVALVE

(S)CYLINDERSENSOR

SMARTFITROOM UNIT

POLARITYFREE

3 PORTVALVE

(Y)

HWVALVE

(S)

Y PLAN

UNIT

HW VALVE (S)

CH VALVE (S) CYLINDERT/STAT

N

N

L

Smartfit Layout:Example shown S Plan configurationDouble Pole

Fused Spur

L

EN

L

N

L

SL

PL

230V MainsVoltage

Page 101Worcester wiring guide Greenstar gas-fired boilers

Greenstar i SystemSmartfit Control Pack

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 101: Gas Boiler Wiring Guide

Optional:Third Party Room Thermostat:

Using the Worcester Internal DT20 Timer an External Third Party Room Thermostat must be connected to the boiler on the External Controls section of ST10 (NS, LS & LR).

LNS NLSLR

FSFR NP LP

78

9

LNS NLSLR 78

9

FSFR NP LP

ST10NOTE:

Leave the link if using Worcester Internal Digital RF units.

SAFETY LIMITTHERMOSTAT

DUAL THERMOSTAT

OPTIONAL:THIRD PARTY

ROOM THERMOSTAT

CYLINDERTHERMOSTAT

DIVERTER VALVEMOTOR PLUG

230V MAINSSUPPLY

N E L

ST6

ST8

Gre

en\Y

ello

w

Connector Block

(made safe)

Bro

wn

Bro

wn

Main Harness

Code Plug

PumpHarness

FanHarness

S112.5 A 230 V AC

S131.6 A

Blu

e

N

CALL COM

S120.5 A

Page 102 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i SystemInternal Diverter Valve with Worcester Controls & Unvented Cylinder

There is a unclarity within the Industry that in order to protect an Unvented Hot Water Cylinder from potentiallydangerous high temperatures from the boiler circuit, a 2-port motorised valve must be installed. This is not thecase, although it is the most common interpretation and approach.

FURTHER DETAILSBuilding Regulation Approved Document G3, paragraph 3.6 states '…the non-self-resetting thermal cut outshould be wired to a motorised valve or some other suitable device to shut off the flow to the primary heater…'.The latter part of this sentence can be interpreted to mean as long as we, as responsible Manufacturer's, areconfident our method provides an equal amount of protection to the common approach, we may instructinstallers of our equipment to follow a different approach. A summary is provided below.

l The installer will use the cylinder sensor supplied with the Integral Diverter Valve kit to control the hot water temperature.

l The installer, therefore, will NOT need to use the hot water control thermostat of the cylinder's dual thermostat.

l The installer may have to alter the wiring of the dual thermostat (depending on cylinder and thermostat manufacturer) to only use the high limit thermal cut-out of the dual thermostat.

l The high limit thermal cut out of the dual thermostat MUST be wired to interrupt the permanent live to the Greenstar CDi System Boiler.

l The 2-port valve supplied with the unvented cylinder will NOT be used. If it is already physically installed in the pipe work is should be removed and electrically disconnected from the wiring centre.

Below you will find an electrical diagram for this arrangement.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 102: Gas Boiler Wiring Guide

Greenstari System

Greenstari System

L NSN LS LRL NSN LS LR

Junction Box/Wiring CentreSwitched Live/

DemandN EL

Double PoleFused Spur

L

EN

C C

C

NO

NC

230V ACDouble Pole Relay

Header LimitThermostat

Wiring from Zone/s Controls

Example relay shown is a Double Pole Mains Voltage Relay. This isolates the Boilers electrically in case of a fault condition.

IMPORTANT NOTE:The Relay should be mounted within a suitable electrically safe housing.

C C

NC NCNO NO

CoilLive

CoilNeutral

230V MainsVoltage

Page 103Worcester wiring guide Greenstar gas-fired boilers

Greenstar i SystemCascade boilers with low loss header

HEADER LIMIT THERMOSTATThis cuts the Demand to the boilers in the event of excessive temperature within the Header dueto lack of circulation. Ideally this should be set to 90º C.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 103: Gas Boiler Wiring Guide

Greenstari System

L NSN LS LR

Double PoleFused Spur

L

EN

Neutral Feed to Wiring Centre

Earth to Wiring Centre

Live Feed to Wiring Centre

Switch Live from Wiring Centre

FR FS NP LP

Frost T/Stat

230V MainsVoltage

Page 104 Worcester wiring guide Greenstar gas-fired boilers

Greenstar i SystemFrost Protection

The boiler has inbuilt frost protection. When the primary temperature drops below 8°C the pump is switchedon. When then temperature rises above 9°C the pump switches off after a 3 minute pump overrun. If theprimary temperature drops below 5°C, a central heating demand is activated until the primary temperaturerises above 12 °C. The demand switches off followed by the pump after a 3 minute overrun.

The boiler has the facility to connect an external frost protection device to protect in “at risk areas” (terminalblock ST6, contacts FS and FR). This is used if the boiler is not located in the area needing protection i.e. boilerin kitchen but pipe work in the garage that needs frost protection.

If external frost thermostat is calling, i.e. temperature within frost thermostat below the set point, but theprimary temperature of the boiler is above 5°C, the pump will run until the temperature within the frostthermostat rises above the set point. If external frost thermostat is calling and the primary temperature isbelow 5°C, a central heating demand is activated until primary temperature is above 12 °C. If the frostthermostat is still calling the pump will run until the temperature within the frost thermostat location risesabove the set point.

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Page 104: Gas Boiler Wiring Guide

Page 105Worcester wiring guide Greenstar gas-fired boilers

Page 105: Gas Boiler Wiring Guide

Page 106Worcester wiring guide Greenstar gas-fired boilers

Page 106: Gas Boiler Wiring Guide

L = LiveL N = NeutralN E = EarthE

The generic Live, Neutral and Earth feed/s to equipment must return to the respective connection on the wiring centre.These connections are denoted as follows:

Worcester, Bosch Group, Cotswold Way,Warndon, Worcester, WR4 9SW.Tel: 0844 892 9900

Worcester, Bosch Group is a brand name of Bosch Thermotechnology Ltd.

This is leaflet is accurate at the date of printing, buy may be superseded and shouldbe disregarded if specification and/or appearances are changed in the interest ofcontinued improvement. The statutory rights of the consumer are not affected.

6 720 646 965 Issue A (09/11)

SalesTel: 01905 [email protected]

Spare PartsTel: 01905 [email protected]

TrainingTel: 01905 [email protected]

LiteratureTel: 0844 892 [email protected]

or download instantly from our website

ContractsTel: 0844 892 [email protected]

Contact CentreTel: 0844 892 [email protected]

Monday – Friday 7.00am – 8.00pm

Saturday 8.00am – 5.00pm

Sunday 9.00am – 12 noon

Technical SupportTel: 0844 892 [email protected]

Monday – Friday 7.00am – 8.00pm

Saturday 8.30am – 4.00pm

Useful Numbers

Calls to the listed 0844 numbers are charged at up to 3 pence per minute from BT landlines.Calls from mobiles and some networks may vary. Calls to and from Bosch Thermotechnology Ltd.may be recorded for training and quality assurance purposes.

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