Tankless Water Heater Training Program Level III Service … Heater Level... · 2019-07-05 · water heater will shut down with a code 14. After the heat exchanger cools, the switch

1 5/4/2018© 2014 Rinnai America Corporation PROPRIETARY and CONFIDENTIAL

Enhancing Lives By Changing The Way Water Is Heated

Tankless Water Heater Training Program

Level III

Service Fundamentals



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/



Factory

Model

Designation

Full Model NumberMin

Btu’s

Max

Btu’s

Min

Activation

Flow Rate(approx.)

Max Flow

Rate 30°

Rise

Max Flow

Rate 50°

Rise

Max Flow

Rate 70⁰Rise

UEF

rating

RL75i REU-VC2528FFUD-US10.3K 180K 0.4 GPM 7.5 GPM 6.0 GPM 4.3 GPM .81

RL75e REU-VC2528WD-US

RL94i REU-VC2837FFUD-US10.3K 199K 0.4GPM 9.8 GPM 6.6 GPM 4.7 GPM .81

RL94e REU-VC2837WD-US

RLX94i* REU-VC2737FFUD-US 10.3K 192K 0.4GPM 9.8 GPM 6.4 GPM 4.5 GPM .81

Specifications: High Efficiency Series (HE+).

HE+ Series: Non-condensing models.

• HE+ series units incorporate “Circ-Logic” programming. Circ-Logic can be used to control an external circulation pump in homes or businesses that have a

dedicated circulation return line.

• Isolation valve kit included with all HE+ models. Essential for servicing and can be useful for troubleshooting.

*Certified to meet California SCAQMD emission standards. Available in natural gas only.

All other models (except RL94iN) meet these standards.



Specifications: High Efficiency Series (HE).

HE Series: Non-condensing models.

Factory

Model

Designation

Full Model NumberMin

Btu’s

Max

Btu’s

Min

Activation

Flow Rate(approx.)

Max Flow

Rate 30°

Rise

Max Flow

Rate 50°

Rise

Max Flow

Rate 70⁰Rise

UEF

rating

V65i REU-VC2025FFU-US10.3K 150K 0.4 GPM 6.5 GPM 5.0 GPM 3.5 GPM .81

V65e REU-VC2025W-US


V75e REU-VC2528W-US


V94e REU-VC2837W-US

V94Xi* REU-VC2737FFU-US 10.3K 192K 0.4 GPM 9.8 GPM 6.4 GPM 4.5 GPM .81

V53e REU-VAM1620W-US 19K 120K 0.6 GPM 5.3 GPM 3.9 GPM 2.8 GPM .81

• HE series units are lower cost models for residential applications only. The HE series units do not incorporate Circ-logic programming and do not come with a isolation valve kit. The V65 and V53 models offer lower cost and lower flow options for smaller applications.

*Certified to meet California SCAQMD emission standards. Available in natural gas only.

Other HE models (except V53e and V94iN) meet these standards



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 VC 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.



• To remove front cover of VC models, press in at the top and bottom of each cover trim strip to release and slidethe strip outward away from the product.

• Remove the four Phillips head screws securing the cover to the cabinet.

Trim strip latch.

Latch receptacle on front cover.

Front Panel Removal – VC Models:



Located inside the front cover of all current Rinnai tankless water heaters is a model specific wiring diagram and a 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.

Front Panel Information:



1. To remove the temperature controller from the mounting bracket, slide the controller up, pull the bottom of the controller, slide the controller down to release the upper mounting tab and remove the controller.

NOTE: the controller is connected to the main PCB by a 15 wire harness. This harness will need to be disconnected from the PCB if the controller is to be completely removed from the unit. The controller in VC (and KB) series indoor water heaters is specific to indoor models.

2. To remove the mounting bracket, remove the single screw at the top of the bracket and lift it out away from the cabinet.

3. Any additional controllers will be connected to the “terminals for controls” on the main PCB. Do not connect the 120 VAC power supply to these terminals.

2

3

1

Indoor Model Control Panel Removal:



1. Heat exchanger thermistor is located at the top left corner of the heat exchanger. To remove, take out the two screws securing the mounting bracket. Pull the thermistor out of the copper tube and disconnect the wiring harness (1.a. lower left side of the cabinet). Make sure the o-ring is intact for re-installation to prevent leaks.

2. Overheat bi-metal switch is located on upper right side of heat exchanger. This switch is wired in series with the thermal fuse and is part of the thermal fuse assembly. This switch will open at 207⁰F. If it opens the water heater will shut down with a code 14. After the heat exchanger cools, the switch will reset and the unit will operate.

3. The thermal fuse wraps around the copper portion of the heat exchanger. This fuse will open at 264⁰F. If it opens the water heater will shut down with a code 14. The thermal fuse is a “one-time-use” component and must be replaced if the fuse opens. Replacement will require removal of the heat exchanger. The thermal fuse and overheat bimetal switch are replaced as one component. To disconnect the thermal fuse / overheat bimetal switch, follow the two wires down the left side of the cabinet and disconnect.

1. 2.

3.

3.

1.a.

Overheat Protection and Safeties:

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



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…

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 will post on the

controller

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

Overheat Protection and Safeties:



Two ceramic heaters are on the left pipes of the heat exchanger

(indoor only)

One long ceramic heater on the right side of the

heat exchanger

One ceramic heater is on the cold water inlet beside

thermistor

Two round ceramic heaters on the water flow servo and

hot water outlet

One ceramic heater on hot water outlet pipe (exterior

unit only)

• 6 ceramic heaters

Interior units

• 5 ceramic heaters

Exterior units

Air inlet thermistor

Outside Air thermistor

Units will fire momentarily if Heat Exchanger

Thermistor senses below 37.4°F

Heat exchanger thermistor.

Freeze Protection, VC Models:



Internal unit ceramic heater locations & wattage

Heat Exchanger Heater Locations:



External unit ceramic heater locations & wattage

Heat Exchanger Heater Locations:



1. Disconnect the sparker wire from the electrode (thick black wire).

2. Remove the single screw attaching the sparker module bracket to the manifold.

3. If bracket and module are to be removed completely, disconnect the wiring harness (two grey wires).

4. Disconnect the solenoid valve harness at each solenoid or at the main connector in the wiring harness (preferred).

5. Remove the 2 screws attaching the manifold to the gas valve assembly.

6. Remove the 6 screws attaching the manifold to the heat exchanger.

6

54

1

2

3

Manifold Assembly Removal:



1. After all screws are removed and electrical connectors disconnected, lift and remove the manifold from the unit.

2. Ensure the gaskets are intact if the manifold is to be reinstalled. 3. The front plate can be removed from the manifold assembly for inspection of the gas passages

and orifices, if necessary (not common).

23

Gas orifices

Gasket

Gas passages

Manifold, rear view

Manifold, front view

Manifold Assembly Removal:



1. Remove 7 screws from the site glass plate (manifold must be removed first).2. Remove 2 clips securing the thermal fuse to the heat exchanger and site glass plate then remove

the plate (flame rod and sparker wires must be disconnected).3. Ensure the gasket/packing is intact for reinstallation (not shown).4. Remove the 2 screws securing the burner box to the heat exchanger (located on the back wall of

the heat exchanger). 5. Slide burner assembly out from the heat exchanger being careful not to damage the heat shield.

4

2 Heat Shield

1

Sight glass plate and burner removal:

Caution: The heat shield and burner assembly have sharp edges.



Four screws need to be removed from the electrode holder if the flame rods and sparker electrode are to be removed from the plate.

Sparker ElectrodeFlame Rods

After the sight glass plate is removed you can clean and inspect the flame rods and the sparker electrode without removing them from the plate. However If these parts are removed from the plate ensure the gasket (packing) remains intact. If not, a new manufacturer supplied gasket must be installed.Note: The wire colors are stamped into the manifold underneath the connectors.

Gasket

Sparker Electrode and Flame Rods:



The burner assembly consists of 17 individual stainless steel burners in one assembly. These can be removed for inspection and cleaning if

necessary (by removal of the surrounding support frame). A wire brush and/or high pressure compressed air pressure can be used to clean the burners.

Burner assembly inspection and cleaning :



1. Ensure unit is isolated from power. NEVER: disconnect fan motor connector with power applied to unit.

2. Disconnect solenoid valves SV1- Black / Blue wires, SV2 - Black / Yellow wires, SV3 - Black / Red wires, and SV4- Black / Orange wires and disconnect the fan motor wiring harness.

3. Remove the four screws attaching fan motor and squirrel cage to the housing (outdoor models have three screws).

4. If installing a new fan assembly, adjust the dip switches on the PC Board for fan sorting. ONLY ON INTERNAL MODELS.See below.

2

3

Fan sorting dip switch settings - see label on replacement fan wiring harness for class information.

Applicable to internal units ONLY

Class A or B fan motor dip switch #6 (of SW2, lower group) should be "ON" & #7 should be "ON"

Class C,D, E or F fan motor dip switch #6 should be "ON" & #7 should be "OFF"

See engineering document #10000286 for more details if needed

3

Combustion Fan Removal:



2

5

• The gas valve consists of the SVO (main) and POV (modulating) solenoid valves only. (SV1,SV2, SV3, and SV4 are attached to manifold).

• There is a clear vinyl pressure balancing tube connecting the gas valve to the heat exchanger on indoor models that will need to be disconnected when removing the gas valve.

• The gas inlet and manifold test ports on the VC models have a special Phillips screw with an O-ring (see #6 below). No threaded adapter is needed. The manometer hose can be slipped over the port. (Test Port set screw: P/N C10D-5 & O-ring: P/N M10B-13-4)

Note: The front cover shows wiring to gas valve solenoids.

1. Remove the manifold assembly (if not already removed). 2. Remove the two (longer) screws from the gas connection fitting. Then remove the fitting ensuring the O-ring

comes off with the fitting. 3. Remove the third screw which secures the gas valve to the bottom of the cabinet. 4. Disconnect the two electrical connectors directly from the solenoids OR disconnect the single connector in the gas

valve wiring harness (not shown). If needed for reassembly, wire color and location information is printed on the wiring diagram inside the front cover of the water heater.

5. Upon reinstallation, ensure the O-ring between the gas valve and manifold is intact with the ribbed side facing the manifold and the flat side against the valve body. Also ensure the gas inlet O-ring is intact.

3

6

Gas valve Assembly removal:



1. Ensure unit is isolated from water & power.

2. Remove screw from hot water outlet pipe retainer. Rotate retainer to release copper pipe. Pull outlet pipe out of the fixture. Ensure o-ring stays intact. (some models have 2 screws).

3. Remove ceramic anti-frost heater (the heater is held in place by the outlet pipe retainer).

4. Remove pan-head screw holding outlet thermistor and pull the thermistor out. Ensure thermistor o-ring is intact and on thermistor upon reinstall. Ensure thermistor is clean.

Heat exchanger outlet cavity

Ceramic heater cavityOutlet thermistor cavity (with O-ring)

2

4

3

Hot water outlet fixture and components:



3

1. Remove the screw(s) from the pipe retainer(s) on the hot water outlet (previous slide) and the water flow servo valve / bypass valve assembly. Rotate the retainer(s) to release and pull the copper pipe(s) out of the fitting. Ensure the O-ring(s) are intact. Note: Variable bypass models will have 2 copper pipes connected to the bypass valve (2.a.). Fixed bypass models will have a “T” fitting attached to the water flow servo valve with 1 pipe connected to the front of the “T” and a bypass pipe connected to the left side of the “T” secured with a spring loaded clip (2.b.).

2. Remove the 2 screws securing the cold water inlet fitting to the bottom of the cabinet. Ensure the O-ring at the top of the fitting is intact.

3. Remove the third (last) screw securing the water flow servo to the bottom of the cabinet. 4. Disconnect the electrical connections for the anti-frost heater, water flow sensor and servo valve

motor then remove the servo assembly from the cabinet.

4

2.b.2.a.

Cold water inlet / Water Flow Servo removal:



Ensure unit is isolated from the power & water supply. Bleed water lines of any built up water pressure.

1. To separate the water flow control valve from the bypass valve, remove the 2 screws shown below. Upon reinstallation ensure the O-ring is intact and the bypass valve is in the correct orientation.

2. To remove the turbine assembly from the servo, remove the plastic retainer ring. The ring is friction fit and can be removed with a small screwdriver or pick. The turbine assembly can then be withdrawn from the brass housing. CAUTION: Turbine is fragile and can be damaged if mishandled.

3. If necessary the turbine assembly can be disassembled. First remove the top cap then the internal components can be removed. Note the order and orientation of the components for reassembly. Reinstall the turbine with the tab on the plastic housing aligned with the notch in brass well of the WFSV assembly.

1 2

WFSV – bottom view. Bypass Valve Assembly

Turbine Assembly

Retainer Ring

Turbine body

Impeller

One-way clutch

Top cap

Water Flow Servo and Bypass Valve:



ELECTRONIC BYPASS FIXED BYPASS NO BYPASS

2532 / R85 / C85

These models use

a variable stepping

motor controlled

bypass.

2520W / R42 / R53

C42 / C53

R94LS / RL94 / RLX94 R70 / V53/ V65/ V75

R98 / C98 / R98LS R50LS / R63LS / R75LS / RL75

RC98 / RU98 / RUC98 / RUR98

RC80 / RU80 / RUC80

RU90 / RUC90 / C199 REU-2424W

2402FFUThis model used a

solenoid valve

Model number will determine what type of bypass is used. This is a sample representation only. Individual

components my vary slightly from what is pictured.

Bypass Valve notes (current models in RED):



2

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

1. MS: Used when connecting multiple water heaters (three or more) to a MSB/MSA multiple system control unit (note, used only when connecting “V” series units to a MSB with a C-3 cable or when using a MSA control system).

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 a circulation pump. This wiring is found only on VC, RL, RU, RUC and

RUR model water heaters that have Circ-Logic programming incorporated).

3

1 4

5

Accessory Wiring:



1. Disconnect electrical power from the water heater. 2. Remove the screw that attaches the top of the PCB to the back of the cabinet (some models may have

a second screw located at the bottom of the PCB. 3. Slightly lift the PCB and rotate it forward and out of the cabinet. 4. When the PCB is accessible disconnect all electrical connectors. Note (or mark) any connections on

the board that are not used. This will aid reinstallation.5. Each connector has a lock that must be released prior to removal. Each connector is keyed to a

specific connection on the board. If the PCB is to be replaced, DIP switch position and gas pressure settings must be verified.

2

4

5

PCB disconnection and removal:



1. Remove manifold and burner assembly (if not removed previously).

2. Disconnect safety circuit, heat exchanger thermistor, anti-frost circuit, sparker module and inlet thermistor.

3. Separate the copper pipes from the inlet and outlet fixtures by removing the machine screws and stainless steel clips holding them in place. Models with a variable bypass will have two copper pipes connected to the bypass valve assembly.

4. Models with a fixed bypass will have a single pipe attached to the water flow servo valve and a separate spring clip connecting the bypass pipe to the bypass “T” fitting on the water flow servo valve.

5. Remove clear tube from the bottom of the gas valve. (indoor models only)

6. Continue to outdoor or indoor unit’s specific instructions

4

3

3

Outlet fixture

Inlet pipes on variable bypass models

Fixed bypass connection

Heat Exchanger Removal (steps common to indoor

and outdoor VC models):



See previous slide/page for initial steps

1. Remove two screws at top of heat exchanger.

2. Remove the six screws securing the flue outlet to the heat exchanger. (necessary only if heat exchanger is to be replaced).

3. Remove two screws on heat exchanger brackets attaching heat exchanger to rear of cabinet.

4. Heat exchanger should pull free from cabinet.

5. Transfer to new heat exchanger:

• thermal fuse

• overheat bimetal

• heat exchanger thermistor

• Incoming water thermistor

• anti-frost heaters

• Flue outlet

1

3

2

Heat Exchanger Removal (outdoor VC models):



See previous page: “Heat Exchanger Removal: Common to indoor or outdoor units” for initial steps.

1. Remove screws on top brackets on both sides of the heat exchanger exhaust cap.

2. Remove the screws from support brackets at the bottom of the heat exchanger.

3. Heat exchanger and air inlet duct assembly should pull free from unit.

1

2

Note: The air inlet duct for interior units is attached to the rear

of heat exchanger assembly.

Heat Exchanger Removal (indoor VC models):

Left Side Right Side

3



1. Remove six screws on top left and right side attaching Hex to air inlet duct.

2. Remove two screws on lower brackets of heat exchanger attaching it to the air inlet duct.

3. The air inlet duct should pull free from the heat exchanger.

4. Remove four screws from fan bracket housing in order to remove it from the bottom of the heat exchanger.

5. Remove four screws from the flue connection assembly to remove it from the top of the heat exchanger .

6. Transfer to new heat exchanger:

1. thermal fuse circuit

2. overheat bimetal

3. heat exchanger thermistor

4. Incoming water thermistor

5. Anti-frost heaters

6. Flue connection assembly

1 2

3

4

5

Heat Exchanger Removal (indoor VC models inlet air

duct removal):



When all installation guidelines are followed, the heat exchanger should last for many years. Primary reasons heat exchangers fail:

Freeze damageRinnai indoor water heaters have internal freeze protection when

outside temps are as cold as -22°F (-30°C)—outdoor units when temps are as cold as -4°F (-20°C) provided adequate power and gas supplies are present. Utilize the optional

drain down configuration if needed.

Condensation from incorrect venting

High efficiency appliances create condensation. Incorrect venting not

only can cause operational issues and shortened vent life, but the acidic condensation will corrode

water heater components including the heat exchanger.

Internal scaling from poor water qualityInadequate water quality creates internal

insulation issues which can affect performance and eventually deteriorate

the copper tubing. High operating temperatures can accelerate this

condition. Ensure the water quality meets the National Secondary Drinking

Water Standards (EPA Guideline).

THESE ARE INSTALLATION AND/OR APPLICATION ISSUES THAT MUST BE CORRECTED TO PREVENT RECURRENCE OF THE FAILURE — NOT WARRANTY CLAIMS

Causes of Heat Exchanger Failure:



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 Diagnostic Points:



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 breaker.b. Check power at PCB connector F, pins 1 & 3

(on PCB, not shown).c. Check fuse mounted on PCB.

2. Measure continuity of Safety Circuit: a. Check for continuity from white wires at

connectors B7 and B8 (use upper half of the connectors.

3. Measure resistance of manifold solenoids: a. Measure resistance of SV3, connector B4

(black / red wires). b. Measure resistance of POV, connector D1

(pink / pink wires).

4. Measure resistance of the heat exchanger thermistor connector E4.

a. While measuring, squeeze the thermistor bulb and note the change in value. The resistance value will be inverse to the temperature. As temperature increases the resistance will decrease.

2.a.

3.a.

3.b.

4.a.

Electrical Diagnostic Points:



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.

Wiring Diagram/Schematic:



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.

Temperature controller guidelines are identical for non-condensing and condensing models

MC-195T

Temperature Controllers:



When multiple controllers are

installed, the priority button

allows each to individually set

temperature output of the water

heater. The priority indicator

reports which controller has

control.

Indicates the selected

water temperature.

Diagnostic Codes flash if

operator intervention is

required.

ON/OFF BUTTONMODEL NUMBER

IN USE INDICATOR

Indicates if the water

heater is in operation.

TEMPERATURE INDICATION

THERMOSTAT

Increases or decreases the

desired water temperature.

PRIORITY BUTTON & INDICATOR

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

Turns the water heater ON and

OFF. Power will still be applied

to the unit when OFF and

diagnostic functions are still

operable.

The model number will

indicate if the controller is

a standard or commercial

controller.



• MC-91-2 and MCC-91-2 controllers replaced the MC-91-1 and MCC-91-1 controllers.

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

• The -2 controllers retain all functions found on the -1 controllers plus have additional functions.

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

The alternate temperature settings are intended to provide additional temperature increments between 140⁰F and 185⁰F for commercial applications.

• Expanded Diagnostic functions are standard on the MC-91-2 and MCC-91-2 controllers.

• Controller has a locking function.

MC-91-2 / MCC-91-2 Controller Functions:



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 SW1 (upper set of switches).

** Temperatures above 140⁰F will require the use of a MCC-91 controller. When a MCC-91 controller is connected, the higher temperatures will be available on all controllers in the same system. Maximum temperature on some models will be limited to 160⁰F.

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

*These alternate temperature settings are available with MCC-91-2 controllers only. Alternate temperature settings are primarily for commercial applications. To select the alternate temperature settings, set dip switches #2 and #3 to the ON position on SW2 ( lower set of switches).

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

Alternate Settings

Temperature controllers: Temperature ranges.

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



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

• These built-in controllers have the same model number and are identical in function to the wall mounted MC-91-2 controllers but are connected to the main circuit board by a 15 wire harness and connector. Any additional controllers, or controllers for outdoor models, are connected to the circuit board by only 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 on the main circuit board controls actual pump operation.

• Dual Timer Programs.

• Override Function to allow interruption of the timers without changing timer settings.

• Function Lock.

• Power Saving feature.

• Clock.

• Combustion and Circulation indicators.

MC-195T Timer/Controller:



Maximum default temperature setting of 120⁰F (49⁰C).

• This limit meets the requirements of various local 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 SW1 bank of 8 (upper set) DIP switches.

NOTE: The V53e and RUS/RUCS models

do not come with a temperature

controller. Temperatures above 120⁰F are

obtained by dip switch settings.

Temperature controllers: Maximum temperature limit.



Temperature controller connection

• Refer to owner’s / installation manual of each model for specific installation instructions.

• Outdoor models come with an separate temperature controller to be mounted remotely and connected to the terminals located on the PC Board. Additional controllers (for indoor and outdoor models) are also connected here.

• Controllers operate on 12 VDC which is supplied from the PCB and should never be connected to supply voltage (120 VAC).

• Controllers should be located in the interior of the 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 be wired in parallel.

• See the installation manual for compatibility of other optional controllers.



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 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”.




The following diagram relates fault codes to individual components and their PCB connections. It can be used as an aid in troubleshooting. NOTE: Diagrams can vary by model. 12 or 72

14

61

11, 12,

11, 12, 52

32

33 or 16

31

11

10, 11, 70 or 12

Unit not firing

LS/VB SERIES-EXAMPLE

34

11 or 12

Fault Codes:



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.

• 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 slug of unheated 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.

625/4/2018 Rinnai Proprietary & Confidential

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 (VC) SW1 SW2

• The procedure can be found on Technical Data Sheet located inside front cover of unit• The VC and KB models adjustments are both electronic, no mechanical adjustment of 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 (VC and KB series):



Manometer connection point (VB)

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 plug 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).

8. Set the unit to “Forced Low” combustion by setting dip switch #7 in SW1 to ON, (fig. 3). 9. Check the manometer for the correct pressure reading. 10. If needed, remove the rubber access plug and adjust the low fire regulator screw on the

modulating valve as required (fig. 4)11. Set the unit to “Forced High” combustion by setting both 7 and 8 dip switches of SW1 to ON

(fig. 5). Ensure you have maximum water flow. 12. Check the manometer for the correct pressure reading.13. If needed, adjust the high fire pressure potentiometer on the PC board as required

(potentiometer located above the dip switches (fig. 1). 14. Return the unit to normal operation by setting dip switches 7 and 8 back to OFF. 15. Close hot water tap.16. Turn off the gas and 120 volt power supply. 17. Remove the manometer and re-install the test port plug. 18. Turn on the electrical and gas supply. 19. Operate the unit and check for gas leaks. 20. Reinstall the front panel.

• The procedure can be found on Technical Data Sheet located inside front cover of unit• The low fire adjustment to the gas valve is mechanical. The high fire adjustment is electrical.

SW2SW1

High Fire Potentiometer

Setting Manifold Gas Pressures (VB, RC and older):



Setting Manifold Gas Pressures:

Upon installation, 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 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 setting chart.



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.

685/4/2018 Rinnai Proprietary & Confidential 685/4/2018 Rinnai Proprietary & Confidential

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 Tankless Water Heater

Training Program Level III

Service Fundamentals

101103

Documents

Tankless Water Heater Training Program Level III Service … Heater Level... · 2019-07-05 · water heater will shut down with a code 14. After the heat exchanger cools, the switch