Rinnai Condensing Tankless Water Heater Training Program Level … Heater Level 3... · 2019-07-05 · Tankless Water Heater Level III, Service Fundamentals course is ... Rinnai needs

1 5/4/2018© 2016 Rinnai America Corporation PROPRIETARY and CONFIDENTIAL

Enhancing Lives By Changing The Way Water Is Heated

Rinnai Condensing TanklessWater Heater Training Program

Level III Service Fundamentals



The following Rinnai Condensing

Tankless Water Heater Level III,

Service Fundamentals course is

approved for NATE continuing

education units in the following

specialties.

Efficiency Analyst Senior – 6 units

Gas Heating (Air) Installation – 6 units

Gas Heating (Air) Service – 6 units

HVAC Performance Verifier – 6 units

Hydronics Gas Installation – 6 units

Hydronics Gas Service – 6 units

Hydronics Oil Installation – 6 units

Hydronics Oil Service – 6 units

Oil Heating (Air) Installation – 6 units

Oil Heating (Air) Service – 6 units

If you require credit

for NATE, please

notify the instructor.



Rinnai SE+ and Commercial Series Condensing Water Heaters.

C199 Commercial

Series

RU/RUC/RUR SE+ Series.



Rinnai Service and Support (800-621-9419)

CRC – Consumer Response Center – general calls, consumer questions, etc.

Available from 8 a.m. to 8 p.m. EST, Monday – Friday.

Parts Department – parts orders.

Available from 8 a.m. to 8 p.m. EST, Monday – Friday.

Warranty Department – warranty claim issues.

Available from 8 a.m. to 5 p.m. EST, Monday- Friday.

Technical Support Department – technical issues related to the function and repair of Rinnai products.

Available in the office from 8 a.m. to 8 p.m. EST, Monday – Friday AND 24/7/365 on call support for technicians who are at the service location. Technicians only, call 1-888-RINNAIS ( 888-746-6247)

Engineering / Applications Department – calls related to product use and applications including sizing.

Available from 8 a.m. to 5 p.m. EST, Monday - Friday.

Rinnai America also provides the following websites for support:

•www.rinnai.us –for installation manuals, product specifications and supporting documents. More technical information is available in the “Partner Portal” section of the website. Registration is required for access.

• www.trainingevents.rinnai.us – to register for Rinnai product training live and online classes and videos. Service manuals, installation manuals and other technical documents are available under the “Resources” section of the site.

http://www.rinnai.us/

http://www.trainingevents.rinnai.us/



Model

Designation Full Model NumberMin

Btu’s

Max

Btu’s

Min

Activation

Flow Rate(approx.)

Max Flow

Rate 35°

Rise

Max Flow

Rate 50°

Rise

Max Flow

Rate 70⁰Rise

UEF

Rating

RUC80i REU-KBD2530FFUD-US15.2K 152K 0.4 GPM 8.0 GPM 6.0 GPM 4.2 GPM .92

RU80e REU-KB2530WD-US





RUR98i REU-KBP3237FFUD-US15.2K 199K 0.4 GPM 9.8 GPM 7.6 GPM 5.4 GPM .92

RUR98e REU-KBP3237WD-US

Specifications: SE+ and Commercial series.

SE+ and Commercial Series: Condensing models.

C199i REU-KBD3237FFUDC-US15.2K 199K 0.4 GPM 9.8 GPM 7.6 GPM 5.4 GPM

96%

Thermal

EfficiencyC199e REU-KBD3237WDC-US



Before Performing Service:

• Disconnect the electrical power source.

• Shut off the gas supply.

• Shut off the water supply and drain down the system.

Note:

1. All components in Rinnai tankless water heaters are field replaceable.

2. All major replacement parts are accompanied with replacement procedures.

3. Rinnai will pay reasonable labor for warranty parts changed during the labor warranty period. Normally one hour labor will be paid for most parts and two hours for the heat exchanger.

General Service Instructions:



For service, troubleshooting, and component replacement, the following primary service

tools will be needed (other hand tools might be needed on occasion).

Long #2

Phillips Head

(magnetic)

Small

Phillips

Head U-Tube Digital

Multimeter

(Volt/Ohm Meter)Screw Drivers Manometer

and

or

If Rinnai technical support assistance is required please have these tools available in order to

speed up the troubleshooting process. Also, Rinnai needs to know the full model and serial

number of the product. Have the front cover removed from the product, record and provide any

relevant information such as gas pressures, set temperature, fault codes etc. The service

provider should utilize the tech sheet and/or service manual to troubleshoot the product as

much as possible prior to the call.

Primary Service Tools



Water Heater

DISASSEMBLY & REASSEMBLY

The following procedures are for KB series water heaters.

Other Rinnai models may vary slightly in design and service requirements.

Please refer to each model’s install guide and service documentation for model specific information.

PLEASE STAY WITH THE PRESENTATION DURING DISASSEMBLY AND REASSEMBLY.



Front Panel Removal

To remove front cover press on the

plastic strip roughly 3” down from the top

of the unit and 3” up from the bottom.

(See circles shown for approximate position).

Slide the plastic strips to the side to

remove from the unit. This will expose

the 4 screws securing the front cover.

Removing the four Phillips head screws

and remove the front cover.



Front Panel Information

Located inside the front cover panel of

all Rinnai Tankless water heaters you

will find a wiring diagram and technical

data sheet. The technical data sheet

contains operation, troubleshooting and

service information including:

• Error code information

• Dip switch/gas pressure settings

• Electrical component test values

• Temperature controller information

• Parts breakdown and part numbers

Technical data sheet

Wiring diagram



1. For internal models, with the front

panel removed, slide the temperature

controller upwards in the mounting

bracket. Pull the bottom of the

controller forward so that the lower tab

is clear. Slide the controller down to

remove. The integrated controller is

connected to the PCB with a 15 wire

harness. The controller can be placed

to the side if it does not need to

removed completely.

2. Any additional controllers or controllers

for external units will be connected to

the “terminals for controls” on the PC

board. DO NOT connect the 120 volts

AC power supply to these terminals.

3. Remove the controller mounting

bracket by removing the power wire

clamp and the ground wire then the

two screws at the bottom of the

bracket.

1

Temperature

controller for

Internal models

2

Temperature controller

3



Overheat Protection and Safeties

1. Heat exchanger outgoing hot water thermistor: Located at the middle left side of the heat exchanger. This thermistor monitors water temperature leaving the heat exchanger. This will be the hottest water in the unit. If the water temperature gets too hot (close to boiling point) the burners will be turned Off.

12. Hot water outlet thermistor: Located in the hot water outlet fitting at the bottom of the unit. If the outlet water exceeds the set temperature by 6⁰F - 8⁰F the burners will be turned Off.

2



Overheat bi-metal switch(es) are placed at various locations inside the water heater to monitor for overheat conditions.

1. Overheat switch #1 is attach to a copper pipe on the right just above the secondary heat exchanger. This switch opens at 207⁰F causing water heater shut down with a code 14. The switch will close after the unit cools. The unit must be reset by stopping water flow or turning the unit OFF then ON a the controller.

2. Burner overheat switches #2 are located at the top, back side of the burner assembly. There are two switches wired in series. These switches open at 302⁰F causing water heater shut down with a code 57. These switches will close after the unit cools but the water heater must be reset by disconnecting and reapplying electrical power.

3. Secondary Heat Exchanger overheat switches #3 are located on the back of the secondary heat exchanger on either side of the exhaust duct. There are two switches wired in series. These switches open at 212⁰F causing water heater shut down with a code 58. These switches will close after the unit cools but the water heater must be reset by disconnecting and reapplying electrical power.


1

2 3

2

3



1. The thermal fuse wraps around the copper portion of the heat exchanger assembly. This device’s primary function is to monitor for high temperatures in the water heater cabinet due to physical damage to the heat exchanger that would allow hot exhaust gasses to escape.

The thermal fuse will open at 264⁰F. If the thermal fuse opens the water heater will

shut down with a code 14. The thermal fuse is a “one-time-use” component

and must be replaced once open. It will not reset. Replacement will require removal of the heat exchanger. This allows the service provider to inspect the entire heat exchanger assembly for damage.

*The thermal fuse and overheat bimetal switch

are wired in series and are replaced as one component.


An open thermal fuse or bi-metal switch is a symptom of an underlying issue such as a failed/damaged heat exchanger, scale buildup inside the copper tubing, dirty or clogged heat exchanger, improperly set gas

pressures, incorrect gas type or an improper gas type conversion. The cause of this symptom should be investigated to prevent further problems.

1

*



The Rinnai Safety “Line of Defense”Multiple layers of technology ensure safe operation

If the heat exchanger thermistor detects

unusually slow heat dissipation after the

flame stops…

If the outlet thermistor detects

6-8⁰F over the temperature set

point…

If the overheat bimetal detects

207⁰F, 212⁰F, or 302⁰F (depending on

which bi-metal opens)…

If the heat exchanger thermistor detects a

boiling condition (approx. 210⁰F)…

If the thermal fuse detects

264⁰F…

An LC warning code will post on the temperature controller (unit will shut down but can be reset,

see procedure in the fault code section)

The flame will turn off until the

temperature decreases (no

code is posted)

The safety circuit is broken and a code 14, 57 or 58 will post on

the controller and the unit will shut down

The flame will turn off until the

temperature decreases (no

code is posted)

The safety circuit is broken and a

code 14 will post on the controller and the unit will

shut down.




The freeze protection system on the RU/RUC and C199 model water heaters consists of electrically powered ceramic heater elements installed on several pipes and fittings inside the water heater cabinet.

Heater activation is triggered by the outside air temperature thermistor (thermistor #1) and/or the intake air temperature thermistor (thermistor #2).

Thermistor #1 (indoor and outdoor models) measures the air temperature outside of the water heater cabinet.

Thermistor #2 (indoor models only) measures the air temperature coming into the cabinet through the vent system.

Heaters are turned on when thermistor #1 or #2 detects air temperatures below 39⁰˚F.

The main circuit board will cycle the heaters On and Off on a specific cycle based on the air temperature.

NOTE: Adequate incoming power is required for the freeze protection system to operate correctly!

Freeze Protection Operation

Thermistor #2

Thermistor #1

Ceramic Heater examples



NOTE: It is important the water heater is

disconnected from the electrical power supply prior

to removing the fan assembly otherwise damage to

the fan control circuit could occur.

1. Disconnect the fan electrical connector.

2. Remove the screw or plastic rivet securing the fan air

inlet tube. Remove the tube.

3. Remove the two screws securing the fan assembly

to the burner assembly. Slide the fan forward and out

of the cabinet.

3

1

2

Combustion Fan



The burner assembly is located at the top of the Heat Exchanger assembly. Attached to

this assembly are the…..

1. Gas Manifold.

a. Solenoid valves.

b. Gas pressure test port.

c. Gas supply tube.

2. Sight Glass Plate.

a. Flame rod.

b. Thermocouple.

c. Igniter electrode.

d. Sight glass.

Gas Manifold Assembly / Sight Glass Assembly

1

1a 1a 1a1b

1c

2

2a 2b 2c 2d



3

2

1

Sight Glass Assembly Removal

1. Disconnect the flame rod wire (yellow) by pulling up.

2. Remove the burner thermocouple by removing the single attachment screw and pulling the

assembly out of the burner assembly. If the thermocouple needs to be completely removed

from the unit, follow the red and white wire harness until you come to a connector. Disconnect

the connector.

3. Disconnect the igniter electrode by pulling straight up on the heavy black wire. Remove the

silicon insulator boot by pulling out to the front.

4. Remove the sight glass

plate by removing the 5

screws securing it to the

burner assembly and

pulling the plate out away

from the unit.

NOTE: The gasket

underneath must be

replaced prior to

reassembly.



SV2 SV1 SV3

Gas supply

pipe

Manifold Assembly Removal

1. Disconnect the wiring and remove the thermocouple as outlined on the previous slide (the sight

glass plate can stay in place).

2. Disconnect the wiring harnesses from the solenoid valves: SV1 (black & blue), SV2 (black &

yellow), SV3 (black & red).

3. Disconnect the gas supply pipe by removing the single screw holding the retaining clip.

Remove the clip and pull the gas line to the right until is clears the manifold. Ensure the o-ring

is intact. (for reassembly, ensure the o-ring is on the supply pipe and not inside the manifold

opening. This will reduce the possibility of the o-ring being cut upon reassembly.

4. Remove the 10 screws

securing the manifold to

the burner assembly.

5. Pull the manifold forward

away from the unit.

6. Inspect the gasket

underneath for any

damage.



SV2 SV1 SV3

Manifold Assembly

The three solenoid valves noted on the previous slide, (SV1, SV2 & SV3)

control gas flow through the manifold and supply gas to three different sections

of the burner.

Section 2 Section 3Section 1

The water heater will

utilize one, two or all

three solenoids/sections

of the burner as well as

modulate the gas input in

order to supply the

proper Btu to meet the

water flow and output

temperature demands.



1. Remove the retainer clip securing the thermistor. Pull thermistor out of

the fitting. Ensure the o-ring is intact and in good condition before

reinstallation.

2. Follow thermistor wiring back to the electrical connector. Disconnect and

remove it from unit.

retainer clip

1.Thermistor

Heat Exchanger Thermistor Removal

2.

Electrical

connector

1.

RUR model shown.



Outgoing Water Thermistor Removal

1

1. Remove the single screw securing the

thermistor. Pull thermistor out of the fitting.

Ensure the o-ring is intact and in good

condition before reinstallation.

2. Follow thermistor wiring back to the

electrical connector. Disconnect and


1

RUC model shown here.

RUR model shown here.



Inlet Water Thermistor Removal

1. Remove the retaining clip securing the

thermistor. Pull thermistor out of the fitting.

Ensure the o-ring is intact and in good

condition before reinstallation.

2. Follow thermistor wiring back to the

electrical connector. Disconnect and


1

NOTE: The inlet water thermistor is used for Circ-Logic operation ONLY. If this thermistor is disconnected or damaged the controller will display a fault code 51 and the water heater will continue to produce hot water, however, the Circ-Logic function will be disabled.



Note: Disconnect the following wiring

harnesses prior to removing the burner and

heat exchanger assembly.

1. Heat exchanger thermistor.

2. Ceramic heaters (green connectors, white wires).

3. Secondary heat exchanger overheat switch (red

wires).

4. Gas manifold solenoids (SV1, SV2 & SV3).

5. Burner thermocouple connector.

6. Freeze protection thermistor.

7. Combustion fan motor.

8. Ignition module.

9. Thermal fuse (two connectors).

10. Inlet water thermistor.

Release any wire harnesses that may be

attached to pipes or fittings that will come out

with the exchanger assembly.

1

2

3

4

6

7

8

9

5

10

Heat Exchanger Assembly Removal



1. Remove single screw from bracket securing pipe to the hot water outlet.2. Remove (2) screws from the brackets securing the two pipes to the bypass valve assembly.

Rotate and remove brackets then release the copper pipes by pulling the pipes straight out from the fittings.

3. Compress pinch clamp securing the condensate drain hose to the bottom of the secondary heat exchanger and pull the hose down and off.

4. Remove the (2) screws from the bracket securing the gas pipe to the gas valve (at the bottom) and the single screw from the bracket securing gas pipe to the manifold (at the top) , release the brackets and remove the pipe.

5. Remove the black heat exchanger drain nipple (threaded) then the (2) screws securing the drain fitting to the bottom of the water heater cabinet.

1 2

4

3

5




32

1. Remove 4 screws securing the concentric vent adapter to the top of the cabinet (only three screws are visible in this illustration).

Pull up to remove the adapter. 2. Remove six screws securing the upper part of the heat

exchanger assembly to the cabinet. Two screws secure metal support brackets and 4 screws secure the (black) exhaust duct.

3. Remove 4 screws securing the lower part of the heat exchanger assembly to the cabinet. All 4 screws are in the lower metal support bracket underneath the secondary heat exchanger.

4. Carefully lift the heat exchanger assembly from the cabinet.

1




Remove the exhaust duct from the back of the heat exchanger assembly by removing the 9 screws at the bottom that secure it to the secondary heat exchanger.

1

Lower Support Bracket

Exhaust duct assembly.




1

Burner Assembly Removal

To access the burners for service or if the heat exchanger is being replaced, the burner assembly at the top of the heat exchanger assembly will need to be removed.

1. Remove the 15 screws securing the burner to the top of the heat exchanger.

2. Once the screws are removed, the burner assembly can be lifted off the heat exchanger assembly.

2

NOTE: If the burner is removed, the gasket must be replaced.



1. Ceramic burners (two ceramic

bricks, operates in three sections). 2. Igniter electrode.3. Flame Rod. 4. Burner Thermocouple.

1

2

34

Burner Assembly Components

23 4



To remove the Secondary Heat Exchanger:

1. Remove the 14 screws securing it to the bottom of the primary heat exchanger (not all screw locations are visible in illustration #1).

2. Once the screws are removed, the secondary heat exchanger can be removed from primary heat exchanger. (all screw locations are visible in illustration #2)

Secondary Heat Exchanger Removal

NOTE: If the secondary heat exchanger is removed, the gasket must be replaced.

1

2



1. Remove 2 screws from bracket securing gas line to the

valve. Rotate retainer to release. Pull the line out away

from the valve. Ensure the o-ring is intact.

2. Disconnect the POV solenoid wiring harness (at the

solenoid or the connector in the middle of the harness -

yellow/yellow wires on rear of gas valve).

3. Unplug SV0 main solenoid harness (pink/black wire on

front of gas valve).

4. Remove 2 screws that secure the gas inlet fitting to the

bottom of the water heater cabinet and gas valve. Pull

the fitting off of the unit. Ensure the o-ring is intact.

5. Remove the remaining screw from the bottom of the unit

and remove the gas valve from the cabinet.

31

2

4

Gas Valve Assembly Removal

5



1. Remove screw from hot water outlet pipe retainer. Rotate retainer to release the copper pipe.

Pull pipe out away from fixture. Ensure o-ring stays intact.

2. Remove ceramic anti-frost heater from fixture. The corner of the retainer holds the heater in

place.

3. Remove pan-head screw holding outlet thermistor and remove the thermistor by pulling straight

out. Ensure the thermistor o-ring is intact.

1. Hot water outlet

2. Heater

3. Thermistor

23

Hot Water Outlet Fitting

1

4. To remove the fitting, remove the three screws securing it to the bottom of the cabinet.

4



Water Flow Servo / Bypass Valve Removal

1. Remove (2) screws from the brackets securing the two pipes to the bypass valve assembly. Rotate and remove brackets then release the copper pipes by pulling the pipes straight out from

the fitting.2. Remove (2) screws from the cold water inlet fitting. Pull the fitting down away from the cabinet. 3. Remove the one remaining screw that secures the water flow servo valve assembly to the bottom of the

cabinet. The assembly will now be free of the unit. 4. Disconnect the wiring harnesses for the servo motors (water flow servo & and bypass servo), the water

flow sensor and the anti-freeze heater. 5. The assembly can now be removed from the cabinet.

12

3

NOTE: This procedure is for the RU/RUC and C199 models. The RUR model procedure will be explained on another slide.



2

Water Flow Servo / Bypass Valve Removal

1. The Water Flow Servo and Bypass Servo are separate components but are removed as an assembly.

2. To separate the servos, remove the two screws holding the brass bodies together then separate the components.

NOTE: Do not remove the white plastic motor housing from the valve body.

3. To remove the flow turbine for cleaning or replacement, remove the plastic retainer ring. This ring is friction fit and can be removed with a small pick or screwdriver.

4. The turbine assembly can now be withdrawn from the housing. If necessary, the turbine can be disassembled: First remove the top cap then the internal components.

Note the order of removal and orientation of the components for ease of reassembly.

Bypass Servo

Water Flow Servo

Retainer Ring

Turbine body

Impeller

One-way clutch

Top capRetainer Ring

Turbine

1

CAUTION: The turbine can be damaged if mishandled.

3



Water Flow Servo Valve and Bypass Valve.

WFSV & Bypass Valve Removal - RUR Models.

Internal Check Valve Assembly.

The water flow servo valve (WFSV) and bypass valve on the RUR models are the same components found on the RU/RUC and C199 models but an internal check valve assembly has

been added at the bottom to accommodate the built-in circulation pump.

The steps to remove the water flow servo valve/bypass valve assembly from the RUR models will be covered in the next few slides.

Maintenance on this assembly and water flow turbine are the same as outlined in the previous slides with the exception that the internal check valve assembly will need to be removed from the bottom of the water flow servo valve first.

The water flow turbine is not accessible from the bottom of the water heater as in other models.



Prior to removing the Water Flow Servo and Bypass Valve Assembly on the RUR models, open the manual drains on the bottom of the unit and drain out any residual water.

Water drain (copper hex drain). Check valve drain. Pump drain.

Turn the drain fittings counterclockwise to open.

The water inlet / filter assembly fitting is held in place with two screws as with the other models.

Manual Drains

Cold Water Inlet




Prior to removing the Water Flow and Bypass Servo valve assembly, remove the circulation return pipe and the pump outlet pipe by removing the retaining clipsthen removing the pipes.

After the circulation return pipe has been removed, remove the two screws that attach the internal cold water inlet fitting to the check valve assembly. One screw is seen here.

The second screw is underneath the fitting (not shown).

Remove the inlet fitting from the water heater.

Next remove the pipes from the bypass valve outlet. These pipes are removed as noted in a previous slide.

Inlet Fitting

Top Screw

Circulation Return Pipe


Pump Outlet Pipe

Retaining clips



1. Disconnect all wiring harnesses from the Water Flow Servo Valve and the Bypass Valve.2. Remove the check valve drain from the check valve (turn counter clockwise) and remove the

two screws securing the check valve to the bottom of the water heater cabinet. 3. Now the assembly can be removed from the water heater cabinet.

2.


Internal Check Valve

Water Flow Servo

Bypass Servo



1. To access the water flow turbine, remove the internal check valve by removing the two screws securing it to the bottom of the water flow servo valve.

2. Flow turbine removal and disassembly is the same as other RU models.

Internal Check Valve

Water Flow Servo Valve and Flow Turbine.


1.



Cold Water Inlet / Circulation Return Pipe Fitting.

Internal cold water inlet / circulation Return Fitting.

NOTE: This opening is not used on indoor RUR models. A ceramic heater element is installed here on outdoor models.

View Looking from the Front of Water Heater



Circulation Pump Removal - RUR Models.

To remove the pump, three pipes, one electrical connector, one manual drain and six screws will need to be removed or disconnected. 1. The pipes that need to be removed

or disconnected are….a. Circulation Return Pipe. b. Crossover mode internal

bypass pipe. c. Pump outlet pipe.

NOTE: Some of these components may have already been removed in previous steps.

Circulation Return

Crossover mode Bypass

Pump Outlet

2. Remove the circulation return pipe from the cold water inlet fitting and the pump inlet by removing the retaining clips. Then slide the pipe to the left to disconnect from the fittings.




1. Disconnect the pump outlet pipe by removing the pipe retaining clips at the pump and at the check valve assembly.

2. After the clips are removed, pull the pipe out of the pump outlet and rotate the pipe forward to clear the pump. (The pipe does not

need to be completely removed from the water heater but if desired slide the pipe to the left to disconnect it from the check valve assembly).

Pump Outlet Pipe retaining

clips

3. To remove the Crossover Mode Bypass Pipe, remove the retaining clip at the pump. Disconnect the pipe by rotating the pipe to the right. Crossover Mode

Bypass PipeCrossover Mode Pipe

rotated.




Retaining screws and clip.

1. An alternate method to remove the Crossover Mode Bypass Pipe is to remove the two screws securing the pump inlet fitting to the front of the pump and rotating the pipe and fitting to the right.

2. For adequate clearance, remove the pump inlet fitting from the pipe by removing the retaining clip OR remove the inlet fitting AND the pipe from the hot water outlet fitting by removing the two screws and retaining clip.

The Pump Inlet fitting contains an internal check valve.

Pump inlet and check valve.




1. Disconnect the pump power wire harness (black and white wires).

2. Remove the six screws securing the pump to the bottom of the cabinet.

3. Remove the pump drain (turn counterclockwise).4. Lift the pump assembly until the drain fitting

clears the bottom of the cabinet. 5. Pull the pump forward to remove from the

cabinet.

1. Pump Power wire

3. Pump Drain 2. Pump Mounting

Screws

4

Pump shown with inlet fitting in place.




Pump Inlet.

Pump Outlet.

Pump Inlet Fitting.

NOTE: The pump is shown with the inlet fitting in place. If the pump is to be replaced, the inlet fitting will need to be removed and installed on the new pump.



PC Board Removal

1

1. Remove the two screws at the top and bottom of the PC Board housing. 2. The PCB can now be rotated forward and out of the cabinet for access for troubleshooting purposes or for

removal of the board. There will be a plastic cover over the board, not shown here, that will need to be removed for access.

3. To remove the PCB, disconnect all electrical harnesses. All connectors will have a latch that will need to be released prior to disconnection. Make note of any receptacles that may not be used (3a).

4. When installing a new board ensure the dip switches are set correctly for you model and gas type.

2

3a

3

4



2

Note: There are several wiring harnesses for use with optional accessories.

1. MS: Used when connecting multiple water heaters (three or more) to a MSB/MSA multiple system control unit

2. EZ Connect: Used when connecting two water heaters together with an EZ Connect cable.

3. Anti-Freeze: Used when installing a freeze protection drain-down solenoid valve kit.

4. S-BMS / Air-H: Used when pairing the water heater with a hydronic furnace (air handler) or connecting the unit to a Simple Building Management System interface through the use of a Domestic Priority Switch (DPS).

5. Cut wire to connect pump: For connecting an external circulation pump. RUR models have a built-in pump and will not have this harness).

3

1 4

5

Accessory Wiring:



Key Points of reassembly

• Reassemble in opposite order of disassembly

• Ensure all screws are placed in the correct location and DO NOT over tightened

• Ensure all connections are correct (solenoid valves, etc.)

• Do not place covers on units

Note: Do not apply power until theproduct is inspected by the instructor!

Product Reassembly:



ELECTRICAL

REQUIREMENTS

AND

TROUBLESHOOTING



When verifying electrical values of individual components, the tests must be conducted correctly and safely. It is important to know how to use your test equipment and the specifications of the component to be tested.

Key points when troubleshooting electrical values:

• Ensure volt meter probes are solidly contacting metal in order to obtain the correct readings.

• Insert test probes into the back of electrical connections where possible to prevent possible damage to connection pin contacts.

• Know your meter and how to set it for each type of measurement.

• Ω= Ohms or resistance

• VAC or V~ = AC voltage

• Always set meter to next highest value from range (as listed in manual).

• When measuring resistance, ensure the component is disconnected from the circuit AND power is removed.

• When measuring a solenoid’s resistance, place the meter probes on the solenoid’s lugs (connection points) with the wires disconnected.

A correct resistance reading from a solenoid or transformer coil is not a guarantee that the component is good since the windings can open up when subjected to an electrical load. On the other hand an incorrect value is a very good indication that the component is defective.

For metering values, reference Rinnai’s Tankless Water Heater Service Manual —the “Electrical Diagnostic Points” section (model dependent) or each unit’s technical data sheet located inside the front cover.

ENSURE YOU ARE REFERING TO THE CORRECT PAGE FOR YOUR MODEL!

• A = amps or current.

• VDC or V- = DC voltage.

• A “µ” indicates micro or the scale is X. 000001 (6µA = 6 micro amps = .000006 amps).

• A “K” indicates Kilo or the scale is X 1000 (6KΩ = 6000 ohms).

Electrical Diagnostics:



Meter setting for measuring 120 VAC.

Meter setting for measuring 12 VDC.

Probe configuration for measuring Volts or Ohms.

Meter setting for measuring less than 20,000 Ohms (20KΩ).

Multimeter Settings:



Flame rod current is measured in µA (micro amps). To take this measurement first set the meter to the correct range (be sure to select the AC or DC amp range, the DC amp range is selected in the picture above) then reconfigure the test lead connections for measuring current, as shown above.

Multimeter Settings:



1. Measure incoming voltage:a. Check power at receptacle or circuit breaker. b. Check power to PCB, connector F, pins #1 and #3, black

and white wires. (not shown).c. Check fuse mounted on PCB.

2. Measure continuity of safety circuit:a. Test the thermal fuse circuit between white wire on

connector B7 and white wire on connector B8.b. Check burner overheat switches (OH#2) from the white

wire to the red wire on connector B7. c. Check the secondary heat exchanger overheat switches

(OH#3) between the red wires on connector B6.

3. Measure resistance of gas solenoid valves:a. SV1 (con. B3, black/blue), SV2 (con. B2, black/yellow),

SV3 (con. 4, black/red).b. Modulating solenoid valve (POV) (yellow/yellow).

4. Measure resistance of heat exchanger thermistor (con. E5) OR inlet water temperature thermistor (con. E9). NOTE: Compare reading to temperature range listed on

tech sheet or service manual. Hold thermistor bulb in your hand and note the change

in reading.

2

2

3

3

4




1. Measure incoming voltage at receptacle, should be 120 volts AC.

2. Check at connector “F” on PC board across blackwire pin #3 and white wire pin #1.

3. Verify fuse is not blown.

4. Measure continuity of safety circuit starting at connector “B” pin #1 white wire & connector “G” pin#8 red wire.

5. Measure resistance of gas solenoids valve SV1 on connector “B” black wire pin #4 and blue wire pin #6. Resistance

reading should be between 35 ~ 41 ohms.

6. Measure resistance of the modulating solenoid valve(POV) on connector “D” across yellow wires on pins #1and 2. Should have between 67 ~ 81 ohms.

7. Measure resistance of outgoing water thermistor on connector “E” across white wires on pins #2 and 3.

59 ˚F = 11,4 ~ 14K ohms86 ˚F = 6.4 ~ 7.8K ohms

113 ˚F = 3.6 ~ 4.5K ohms140˚F = 2.2 ~ 2.7K ohms221 ˚F = 0.6 ~ 0.8K ohms.

G

B

F

D

E




Wiring Diagram/Schematic:

For wiring diagrams, reference Rinnai’s

Tankless Water Heater Service Manual or each

unit’s front cover or tech sheet.

IF USING A SERVICE MANUAL ENSURE YOU

ARE READING THE CORRECT PAGE!

• Note: The sections boxed in by dashed lines indicate components found on certain models but not others.



Temperature Controllers



MC-91-2 / MCC-91-2**for commercial use

All current Rinnai models will accept up to four temperature controllers

wired in parallel. NOTE: Only one MC-195T per unit.

MC-195T

Temperature Controllers:



When multiple controllers are

installed, the priority button is

used to select which controller is

setting the output temperature.

The priority indicator reports

which controller has control.

Indicates the selected

water temperature. Fault

codes and diagnostic

functions will be displayed

here.

ON/OFF BUTTON

MODEL NUMBER

IN USE INDICATOR

Indicates if the water

heater is in operation.

TEMPERATURE INDICATION

THERMOSTAT

Increases or decreases the

desired water temperature.

Used in conjunction with

other buttons for auxiliary

functions.

PRIORITY BUTTON & INDICATOR

Temperature Controllers: MC-91-2 / MCC-91-2

Turns the water heater ON and

OFF. Power will still be applied

to the unit when OFF and

diagnostic functions are still

operable. Also used in

conjunction with other buttons

for auxiliary functions.

The model number will

indicate if the controller is

a standard or commercial

version.



• Current production condensing water heaters utilize the MC-91-2 and MCC-91-2 controllers (The MC-91-2 and MCC-91-2

replaced the MC-91-1 and MCC-91-1 controllers).

• Any water heater originally equipped with a MC-91-1/MCC-91-1 controller is compatible with the MC-91-2/MCC-91-2 controller.

• The MC-91-2 controllers have additional functions (compared to the MC-91-1 controller).

• An alternate table of temperature settings are available for commercial applications.

• These alternate temperature settings are intended to provide additional temperature increments between 140⁰F and 185⁰F for commercial applications. These can only be accessed with the “-2” controllers.

• Temperature options without a controller. • The default temperature setting for units installed without a controller is 120⁰F. However the

temperature setting can be adjusted to 140⁰F by setting dip switch #5 in DIPSW1 (upper set of

switches) to the ON position (if a controller is connected, switch #5 has no effect on temperature).

Temperature Controllers: MC-91-2 / MCC-91-2



Standard Temperature Setting Range

Fahrenheit F° 98 100 102 104 106 108 110 115 120 125*

130*

135*

140*

150**

160**

185**

Celsius C° 37 38 39 40 41 42 43 46 49 52 54 57 60 66 71 85

* Default maximum temperature is 120⁰F. Temperature settings of 125⁰F to 140⁰F are available by setting switch #6 to the ON position on DIPSW1 (upper set of switches).

** Temperatures above 140⁰F will require the use of a MCC-91-2 controller on most models.

** NOTE: The C199 commercial model does not require the MCC-91-2 controller for temperatures above 140⁰F.If multiple controllers are connected to one water heater, all controllers will display the same set temperature.

Alternate Temperature Setting Range

Fahrenheit F° 110 115 120 125 130 135 140 145*

150*

155*

160*

165*

170*

175*

180*

185*

Celsius C° 43 46 49 52 54 57 60 63 66 68 71 74 77 79 82 85

*Alternate temperature settings: Alternate settings are primarily for commercial applications. To access these alternate settings, dip switches #2 and #3 should be in the ON position on DIPSW2 ( lower set of switches).

NOTE: When alternate temperature settings are used, the minimum temperature setting will be 110⁰F.

Temperature controllers: Temperature ranges.

NOTE: The maximum set temperature for the RUS/RUCS and RUR98 water heaters is 140⁰F. (Installing a MCC-91-2 controller will NOT allow settings above 140⁰F).



C199i & C199e: (temperature options)

• The C199 models will come with the MC-91-2 temperature controller (built-in on the C199i indoor model).

Indoor models will have a default maximum temperature setting of 140⁰F (DIPSW1, switch #5 will be OFF and #6 will be ON).

Outdoor models will have a default maximum temperature setting of 120⁰F WITHOUT the controller connected (DIPSW1, switch #5 will be OFF and #6 will be ON).

The temperature can be increased to 140⁰F WITHOUT the controller by setting #5 to ON and #6 to OFF.



C199i & C199e: (temperature options)

• To increase the temperature setting above 140⁰F on the indoor model:

Both SW5 and SW6 in DIPSW1 must be set to the ON position.

• To increase the temperature setting above 140⁰F on the outdoor model:

The included MC-91-2 controller MUST be connected and both SW5 and SW6 in DIPSW1 must be in the ON position.



• The factory installed MC-91-2 controllers on indoor models are specific to an indoor model and cannot be relocated or used on an outdoor model.

• These controllers are identical in function to the wall mounted MC-91-2 controllers but are connected to the main circuit board by a 15 conductor wire harness.

• Additional controllers, or the controller for an outdoor model, are connected to the circuit board by two wires. The extra wire needed for remote mounted controllers is to be field supplied.

Indoor model temperature controller.

MC-91-2 Controller (Indoor Models):



• The MC-195T Timer / Temperature controller is for use only with the Rinnai Luxury and Ultra series tankless water heaters equipped with Circ-Logic™ programming (standard equipment with the RUR model water heaters).

• The MC-195T timer controls when the Circ-Logic™ function is ON or OFF.

• The Circ-Logic™ programming controls actual pump operation.

• Dual Timer Programs.

• Override Function.

• Function Lock.

• Power Saving feature.

• Clock.

• Combustion and Circulation indicators.

MC-195T Timer/Controller:

NOTE: In order for Circ-Logic to function on the RUR model, the MC-195T controller will need to be connected.



Maximum default temperature setting for residential models is 120⁰F (49⁰C).

• This limit meets the requirements of various local building codes.

• Enhances the safety of users.

• Temperature settings between 125⁰F and 140⁰F (52⁰ - 60⁰C) are available by setting DIP switch #6 to the ON position in the DIPSW1 bank of 8 DIP switches.

NOTE: The RUS/RUCS models do not come

with a temperature controller - temperatures

above 120⁰F are obtained by dip switch

settings.

Commercial C199 models can achieve higher

temperatures utilizing the standard MC-91-2

controller and dip switch settings.

Temperature controllers: Maximum temperature limit.



Temperature controller connection

• Refer to operation / installation manual of each model for specific installation instructions.

• Separate or additional controllers are to be connected to the “terminals for controls” located on the PC Board.

• Controllers operate on 12 VDC which is supplied from the main PCB. Do not connect a controller to a 120 VAC power supply.

• Controllers should be located in the interior of a structure and protected from heat, direct sunlight and water.

• Two-core, non-polarized wire (min. 22 AWG) can be used to connect the controller to the water heater. The maximum wire length with 1 wired controller is 328 ft. (100 m). This distance will be reduced with additional controllers (see installation manual).

Temperature controllers: Installation.

• Additional controllers must all be wired in parallel.



Auxiliary functions for the MC-91-2 series controllers.

• To change from Fahrenheit to Celsius: With the controller turned off, press and hold the ON/OFF button for approximately 5 seconds. The display will switch to the opposite temperature scale. Repeating the procedure will switch the display back to the original setting.

• Locking the controller: Press the Priority button and the UP arrow (in that order) at the same time for approximately 5 seconds. A beep will sound confirming the lock. The display will alternately show “LOC” and the temperature setting. Error codes will display if needed. All controllers in the system will also lock. To unlock, repeat the procedure.

• Muting the controller: Press the UP and Down arrows together for approximately 5 seconds. The controller will beep once the mute function has been activated. Repeat the procedure to reactivate the beep.

Temperature Controller (Adjustments and Diagnostics):



The MC-91-2 temperature controllers provide the following diagnostic capabilities:

• To display the error code history: Press and hold the ON/OFF button. After 2 seconds, simultaneously press the UP arrow then let go of both buttons. The error code history will be displayed with the most recent recorded error code being displayed first. To exit the error code history, repeat the procedure.

• To enter the maintenance information mode: Press and hold the Down arrow. After 2 seconds, simultaneously press the ON/OFF button then let go of both buttons. An “01” will be displayed briefly followed by the water flow rate (in GPM). To select the next information mode, press the up arrow. An “02” will be displayed followed by the water heater output temperature (in Fahrenheit). Continue to press the up or down arrow to scroll through the remaining information modes *. To exit the information mode, repeat the procedure.

* The remaining info modes are explained on the next page.

Temperature Controller (Adjustments and Diagnostics):



To enter the maintenance monitor display mode: Press and hold the DOWN arrow. After two seconds press the ON/OFF button at the same time. Then let go of both buttons. First “01” will be displayed

followed by a display of the flow rate in GPM. Pressing the UP arrow will change the display to “02” followed by the output water temperature and so on.

Code Reading Units Description / Notes Note: Not all

diagnostic functions

will be available on all

models. If a water

heater does not have

a particular function

that number will be

skipped when

scrolling through the

menu.

*Water flow servo position.

• If the controller reads 1,

the servo is open.


the servo is closed.


the servo is partially

open.

01 Water Flow in GPM. 0.1 GPM GPM Through WH (decimal not shown).

02 WH Outlet Temperature. Deg. F Output Water Temperature.

03 Hours of Operation. X100 Total Combustion Hours.

04 Combustion cycles. X100 Total Combustion Cycles.

05 Fan Frequency. Hertz Fan Motor Hertz (if operating).

06 System Controllers. # of controllers Add together for total # controllers connected to unit.

07 Water Flow Servo Position.* * *See notes.

08 Inlet Water Temperature. Deg. F Calculated Inlet Water Temperature.

09 Fan Current. 10 mA Fan Current Draw (if operating).

10 Total Bath Fill Volume. Gallons Volume of Water During Bath Fill Mode.

11 HEX Temperature. Deg. F Heat exchanger output water temp

12 Bypass Servo Position. Degrees Degrees of opening (if equipped)

13 Burner Thermistor Temperature Deg. F (if equipped)

14 Intake Air Temperature. Deg. F (indoor non-condensing models only)

15 Thermal Fuse Deg. F

16 Thermocouple Value mV (condensing models only)

17 Freeze Protection Temperature 1. Deg. FTemperature reading of freeze protection sensors.

18 Freeze Protection Temperature 2. Deg. F

19 Pump Hours X100 Total pump operation hours (RUR98 models only)

20 Pump Cycles X100 Total pump operation times (RUR98 models only)

Temperature Controller (Maintenance Monitor Functions):



MAINTENANCE / FAULT

CODES



A fault code will flash on the temperature controller when a fault is detected. The unit may stop operating (code dependent). Not all codes are applicable to all models. See the owners manual

or tech sheet for codes specific to your particular model water heater.

ERROR FAULT REMEDY

02 No burner operation during freeze protection mode - Service Call

03 Power interruption during Bath Fill - Turn off all hot water tap. Disable bath fill, turn unit OFF then back ON.

05 Bypass Servo failure - Replace bypass servo.

10 Air supply or Exhaust Blockage

- Ensure Rinnai approved venting materials are being used.

- Check that nothing is blocking the flue inlet or exhaust.

- Check all vent components for proper connections.

- Ensure vent length is well within limits.

- Check Burner Sensor / TC sensor or air temperature thermistor (indoor non-

condensing models.

- Verify DIP switches are set properly .

- Check fan or burners for blockage .

11No Ignition

- Check that the gas is turned on at the water heater, gas meter, or cylinder.

- If the system is Propane, ensure the tank has adequate quantity.

- Ensure the appliance and circuit board is grounded properly.

- Ensure gas type and gas pressure is correct.

- Ensure gas line, gas meter and /or regulator is sized properly.

- Bleed all air from the gas lines.

- Verify dip switches are set correctly.

- Ensure the igniter electrode is operational.

- Check gas solenoid valves for open or short circuits.

- Remove burner cover to ensure burners are properly seated.

- Remove burner plate and inspect burner surface for condensation / debris.

(Continued on next page)

Maintenance: Fault Codes.



12 Flame Failure

-Check that the gas is turned on at the water heater, meter or cylinder.

- Check for obstructions in the flue outlet.

- If the system is propane, ensure the tank has adequate quantity.

- Ensure the gas line, meter and / or regulator is sized properly.

- Ensure gas type and pressure is correct.

- Bleed all air from the gas line.

- Ensure proper venting material was installed.

- Ensure condensation collar was installed correctly.

- Ensure vent length is within limits.

- Verify dip switches are set properly.

- Check power supply for loose connections, proper voltage and voltage drops.

- Check flame rod for carbon buildup.

- Check for DC shorts at components (VB / KA models and prior).

- Check gas solenoid valves for open or short circuits.

- Remove burner plate, inspect burner surface for condensation / debris.

14 Thermal Fuse

- Check for restrictions in air flow around unit and vent terminal.

- Check gas type of unit and ensure it matches gas type being used.

- Check for low water flow in a circulating system causing short-cycling .

- Ensure dip switches are set properly.

- Check for foreign materials in combustion chamber and exhaust piping.

- Check heat exchanger for cracks or separations.

- Check heat exchanger surface for hot spots which indicates heat stress to the HEX.

- Measure resistance of safety circuit.

- Ensure high fire and low fire manifold pressure is correct.

- Check for improper gas type conversion of product.

16 Over Temperature Warning

- Check for restrictions in air flow around the vent terminal.

- Check for low water flow in a circulating system causing short cycling.

- Check for foreign materials in the combustion chamber and exhaust piping.

- Check for blockage in the heat exchanger.

19 Electrical grounding - Check components for an electrical short (VC / KB models and newer ).

25Condensation Trap Error

(Condensing models only)

– Ensure the condensate trap is draining properly.

– Ensure drain lines connected to the trap are not blocked, ensure external condensate pump

is operating (if equipped), ensure a secondary trap is not installed outside the unit.





31 Burner Sensor – Check sensor wiring for damage or disconnection.

– Measure resistance of sensor.

– Clean sensor of scale build-up.

– Replace Sensor.

–Code 38 applies to the RUS/RUCS models only

– Code 41 will allow the water heater to continue operating. Freeze protection heaters will go

into a default heating mode.

– Code 51 will allow the water heater to continue operating but Circ-Logic will be disabled.

32 Outgoing Water Thermistor Faulty

33 Heat Exchanger Outgoing Thermistor Faulty

34 Combustion Air Thermistor Faulty

38 Exhaust Gas Temperature Sensor Faulty

41 Outside Temperature Sensor Faulty

51 Inlet Water Temperature Sensor Faulty

52 Modulating Solenoid Valve Signal Abnormal– Check modulating gas solenoid wire harness for loose or damaged terminals .

– Measure resistance of valve coil.

54High Exhaust Gas Temperature (RUS/RUCS

Models Only)- Check for scale buildup and/or excessive heat to primary / secondary heat exchangers.

57 Burner overheat–Check burner area of heat exchanger for excessive heat or heat damage.

–Check continuity through both Overheat switches #2 and associated wiring.

58 Secondary Heat Exchanger overheat –Check for scale buildup or heat damage to the secondary heat exchanger.

–Check for continuity through the Overheat Switch #3 and associated wiring.

61

Combustion Fan

– Ensure fan will turn freely.

– Check wiring harness to motor for damaged and/or loose connections.

– Measure resistance of motor windings.

63

Circulation Pump

– Ensure isolation valves are open and inlet filter screen is not obstructed.

– Ensure unit is set up properly for the application (dedicated or crossover mode).

– Ensure dedicated return line is not blocked or has a closed valve.

– Ensure Air is purged from piping and return line.

65

Water Flow Servo

- The water flow control valve has failed to close during the bath fill mode.

- Damage to the water flow control valve or wiring / no feedback signal from valve to

main circuit board.





70 PC Board

- Check the PC Board DIP switches for correct position.

- Check the wiring harness connections at the PC Board

- Replace the PC Board.

71 Solenoid Valve circuit - Replace the PC Board.

72 Flame sensing device circuit - Replace the PC Board.

73 Burner Sensor Circuit - Replace the PC Board.

79 Water leak detected- Turn off water supply

- Determine and correct source of the water leak.

LC (00)**Scale Build-up in Heat Exchanger ( “00” is

substituted for “LC” in diagnostic code history)

- LC1 ~ LC9 indicates there is possible scale buildup in the heat exchange. Refer to

instructions in manual.

- Replace heat exchanger in extreme cases of scale buildup or internal clogging.

- To operate the water heater temporarily, push the ON/OFF button on the temperature

controller 5 times. **Repeated LC codes will eventually lock out the water heater.

FF Maintenance Performed

- Indicates a service provider performed maintenance or repair and flagged this action.

- Enter this code in the history by pressing and holding the UP, then Down and then ON/OFF

buttons. The buttons must be pushed in that order.

NO CodeUnit does not operate or post an error code

when water flow is initiated.

- Check/clean inlet water supply filter

- Ensure the minimum activation water flow rate is met.

- Ensure hot and cold water lines are not reversed / cross connected.

- Ensure there is not a crossover / cross connection somewhere in the building plumbing or a

plumbing fixture.

- Check to ensure the water flow turbine is not clogged / damaged.

- Measure voltage to and from the water flow sensor

- Measure the water flow sensor resistances.

** After an LC code is temporary cleared the unit will operate for 70 hours before shutting down again with the next LC code (LC-0 through LC-9). After service is performed (flushing) the LC code sequence will need to be reset to. This is accomplished by pressing the “A” and “B” test switches at the same time for approximately 5 seconds. The unit will return to normal operation and the LC# count will return to “0”.




41


51

61

11, 12, 52

14

57

58

Not firing/no code

11, 12

65

05

25

33

32

63

11, 12

11, 12 19 – electrical

short to ground

70 – Dip

switches / PCB



WATER REQUIREMENTS,

MAINTENANCE

AND

TROUBLESHOOTING



•Pressure regulated and scald prevention fixtures can also cause intermittent flow issues.

•Clogged water filters, sink aerators, filtration systems, etc. can also cause flow issues.

• All of the above are common factors of tankless water heaters—understanding the basic technology and various ways to alleviate such issues is important for consumer satisfaction

• Troubleshooting tip: If after isolating the appliance from the plumbing system and gpm flow and output temperature are verified through the controller’s diagnostic tests, the unit is likely performing to manufacturer’s specifications.

•Crossover is when cold water is introduced into the hot water line after downstream of the water heater.

•When this happens, it can “overtake” the flow from the tankless water heater, thus causing the temperature at the output to scale back.

• If strong enough, the crossover can cause the unit to turn off altogether for a brief moment.

•Crossover can occur in single handled mixing valves, washing machine connections, anywhere there is hot and cold introduced at a single point.

•Cold water sandwich is when a tankless water heater is turned on, off, and on again in a short period of time.

• Due to the 3-5 second activation time, this causes a cold slug of water to travel down the hot water pipe.

Troubleshooting Water Flow Issues:



1. Disconnect electrical power to the water heater, Disconnect from MSA, MSB , or E-Z connect cables from unit (if applicable).

2. Close the shutoff valves on both the hot and cold water lines (V3 and V4)

3. Connect pump outlet hose (H1) to the cold water line at service valve V2

4. Connect drain hose (H3) to service valve V1

5. Pour approximately 4 gallons of virgin food grade white vinegar or citric acid into pail

6. Place the drain hose (H3) and the hose (H2) to the pump inlet into the cleaning solution

7. Reconnect power to unit and allow Water flow servo and Water flow by-pass time to reset to start position, approximately 10-15 seconds. Disconnect power again before flushing.

8. Open both service valves (V1 and V2) on the hot and cold water lines

9. Operate the pump and allow the cleaning solution to circulate through the water heater for at least 45 minutes

10. Turn off the pump

11. Rinse the cleaning solution from the water heater by:

a. Remove the free end of the drain hose (H3) from the pail and place in a suitable drain

b. Close service valve, V2, and open shutoff valve, V4. Do not open shutoff valve, V3.

c. Allow water to flow through the water heater for 5 minutes

d. Close service valve, V1 and shutoff valve V4.

12. Disconnect all hoses

13. Remove the in-line filter at the cold water inlet and clean out any residue

a. Place the filter back into the unit.

14. Open shutoff valves V3 and V4.

15. Restore electrical power to the water heater.

For proper operation, unit longevity, and warranty adherence, water supply to the water heater must meet National Secondary Drinking Water Regulations. In areas with hard

water, a water softener or other conditioning may be needed. A periodic flushing procedure may also be required. Below is the proper flushing procedure:

Maintenance: Heat exchanger flush procedure.



GAS REQUIREMENTS,

MAINTENANCE

AND

TROUBLESHOOTING



•Issues caused by insufficient gas supply:• Poor appliance operation.

• Water heater shutdown and Fault codes.

• Rumbling noises due to insufficient air/gas mixture (this will also happen with incorrect venting).

• Summer installations sometimes operate correctly until winter appliances are operated—thus causing delayed performance issues. Testing gas pressure while all gas appliances are operating at full capacity can prevent such issues.

• If any symptom exists suggesting a gas supply issue may be present, a gas manometer will be needed to verify incoming pressure. Rinnai tankless water heaters only need a single port manometer. Dual port or pressure differential manometers are not needed. Various manometers are shown:

U-tube or Slack tube manometers

Digital manometers

Troubleshooting Gas Issues:



Manometer connection

point. SW1 SW2

• The procedure can be found on Technical Data Sheet located inside front cover of unit• The KB model gas pressure adjustments are electronic, there is no mechanical adjustment of the gas valve.

Gas Pressure Setting - Ensure the gas system is sized properly and a gas pressure check has been completed before proceeding. The water heater’s regulator is electronically controlled and factory pre-set. Under normal circumstances it does not require adjustments during installation. Make adjustments only if the unit is not operating correctly and all other possible causes for incorrect operation have been eliminated.

1. Turn off the electrical and gas supply. 2. Remove the front panel (4 screws).3. Check the gas type using the data plate on the side of the unit. Confirm the gas type dip

switch is in the correct position (fig. 1). Confirm the correct switch from the tech data sheet or the service manual.

4. Remove the test port screw from the manifold and attach the manometer to this test point (fig. 2). Ensure the manometer is “zeroed”.

5. Turn on the gas supply and power supply and ensure the water heater is turned on. 6. Flow water through the unit at the maximum obtainable flow rate (at least 3.0 GPM.

Insufficient water flow could cause the unit to shut off or sustain damage due to overheating).

7. Move switch #8 of SW1 to the ON position (figure 3). 8. Press test switch “A” (figure 4) until the LED light illuminates (approx. 1 sec.).9. Calibrate “Forced Low” combustion using switch “A” (pressure up) or switch “B” (pressure

down) to achieve the specified low pressure setting. 10. Once the specified pressure is reached move switch #8 to the OFF position then back to the

ON position (figure 6). 11. Press test switch “B” (figure 4) until the LED light starts flashing (approx. 1 sec.).12. Calibrate “Forced High” combustion using switch “A” (pressure up) or switch “B” (pressure

down) to achieve the specified high pressure setting. 13. Once the specified pressure is reached move switch #8 to the OFF position. (figure 5). 14. Close the hot water tap. 15. Turn off the gas and 120 volt power supply. 16. Remove the manometer and re-install the test port screw. 17. Turn on the electrical and gas supply. 18. Operate the unit and check for gas leaks. 19. Reinstall the front panel.

Setting Manifold Gas Pressures:



Setting Manifold Gas Pressures:

Upon installation of the water heater, dip switches on the PCB must be set for the correct altitude and vent length. If gas pressure checks or adjustments are made at a later date (due to parts changes, conversions etc.) ensure the dip switches are set correctly for your water heater model, gas type, altitude and vent length then refer to the corresponding gas pressure chart for the proper gas pressure settings.



TROUBLESHOOTING SUMMARYWHEN TROUBLESHOOTING IT IS IMPORTANT TO REMEMBER….

•REMEMBER ALL RESOURCES AVAILABLE TO YOU!!•Rinnai documentation (Tech Service Manual, Installation Manuals, Tech Data Sheets).•Rinnai Support

•Technical Support and Engineering Phone Support.•Local Support (Sales representatives, distributors, etc.)

•Rinnai Websites.•Rinnai online training.

•REMEMBER THE QUALITY OF THE PRODUCT!!•Rinnai’s Quality Control is second to none.

•Every Rinnai Product is tested before leaving the factory.

•REMEMBER THE BASICS!!•Make certain all input parameters are within specifications….water, gas, electricity, and venting.• Isolate the water heater from the plumbing system and check for proper operation. If the water

heater operates per specifications the issue could be a plumbing issue.



Verify DC power Will the unit fire with no controller? Will the

controller light with nothing else plugged into PCB?, Will the controller light with no extra

thermostat wire?

If SERVICE OR INSTALLATION assistance is needed in diagnosing the operation of the product, contact Rinnai technical support at 1-888-RINNAIS

AIR ELECTRICITY WATER

Verify incoming pressureIs there a large drop from between lock up and

load pressure ? This could indicate a volume/line sizing/regulator/meter issues?,

Were all appliances operating during test?, Has the gas line been over-pressurized?, Are

altitude adjustments needed?

Verify correct venting Verify correct parts, seals, custom cuts,

termination clearances, internal airways, high altitude/cold climate adjustments

Verify manifold pressureIf the gas valve was removed, are all solenoids plugged in

correctly?

Verify clean fan Is the fan sealing correctly?, etc.)

Is the problem environmental? (time of day?, weather?, etc.)

Verify input power (Is there adequate power to PCB?, Is incoming polarity correct? Is there a

sufficient ground?

Verify grounding (Is the ground good through entire circuit?,

Have any internal wires been shorted to ground?

Verify all wiring/harnesses(check all harnesses for damage—i.e. water, corrosion, shorts/opens?, etc.)

Verify flow (with unit isolated)

(Is the flow in right direction?, Verify no back flow?, is the filter/turbine clean?, etc.)

Confirm the information? Have you witnessed the symptom?, is your meter or manometer connected/setup correctly? Are the meter probes making good contact?

Verify applicationCould issue be application related (pump sizing, check valve location/orientation,

etc.)

Verify pressure/pipe size

Verify incoming water temperature

(make sure delta T is adequate, Is flushing needed?, Are thermistor bulbs clean?, etc.)

Basic Troubleshootingthis is a general guide and not intended as an official troubleshooting procedure - contact Rinnai technical support if needed.

Verify clean burner areaIs there any condensation debris…why?, signs of leakage….why, Is the flame rod/sparker clean

and properly oriented?

GAS

General Troubleshooting Summary:



This concludes the

Rinnai Condensing TanklessWater Heater

Training Program Level III

Service Fundamentals

701103

Documents

Rinnai Condensing Tankless Water Heater Training Program Level … Heater Level 3... · 2019-07-05 · Tankless Water Heater Level III, Service Fundamentals course is ... Rinnai needs