Rinnai Tankless Error Codes

    Rinnai Tankless Error Codes

    Tankless Systems are complicated, thus, they can have some errors and electronic issues resulting in Rinnai Tankless Error Codes. We have put together a thorough list of Rinnai error codes to help you diagnose and potentially fix any issues you and your tankless may have.

    If Your Rinnai is acting up and needs help, we have fully qualified specialist available.
    Call (647) 925-1930 if we’re not available please leave a message.

    Error Code – 02

    FAULT = No burner operation during freeze protection mode

    Error Code Solutions

    1. Service Necessary Call (647) 925-1930 or 1-800-621-9419 for Rinnai Customer care

    Replacement Parts

    • Not Applicable

    Error Code – 03

    FAULT = Power interruption during use now water will not flow

    Error Code Solutions

    1. Turn off all hot water taps.
    2. Press ON/OFF twice to reset or unplug for 30 seconds to 1 minute and plug unit back in.
    3. Clean the inlet water strainer.

    Replacement Parts

    Error Code – 05

    FAULT = Bypass Servo

    Error Code Solutions

    1. Press ON/OFF twice to reset or unplug for 30 seconds to 1 minute and plug unit back in.
    2. Test for hot water at nearby tap.
    3. If code 05 reappears replace bypass valve.

    Replacement Parts

    Error Code – 10

    FAULT = Air Supply or Exhaust Blockage

    Error Code Solutions

    1. Ensure Rinnai approved venting materials are being used.
    2. Check that nothing is blocking the flue inlet or exhaust.
    3. Check all vent components for proper connections.
    4. Check burner and inspect copper fins for buildup which will cause restrictions and error 10.
    5. Ensure vent length is within limits.
    6. Ensure condensation collar was installed correctly.
    7. Verify dip switches are set properly.
    8. Check fan for blockage or bad fan motor bearing.

    Replacement Parts

    Error Code – 11

    FAULT = No Ignition

    Error Code Solutions

    1. Check that the gas is turned on at the water heater, gas meter, or cylinder.
    2. Ensure gas type and pressure is correct.
    3. Ensure gas line, meter, and/or regulator is sized properly.
    4. Verify all air was purged from gas lines after installation.
    5. Verify gas type dip switch on PC board is switch to proper gas type position.
    6. Ensure appliance is properly grounded.
    7. Disconnect EZConnect or MSA controls to isolate the problem.
    8. Ensure igniter is operational.
    9. Check igniter wiring harness for damage.
    10. Check gas solenoid valves for open or short circuits.
    11. Remove burner cover and ensure all burners are properly seated.
    12. Remove burner plate and inspect burner surface for condensation or debris.

    Replacement Parts

    • Not Available

    Error Code – 12

    FAULT = Flame Failure

    Error Code Solutions

    1. Check that the gas is turned on at the water heater and gas meter.
    2. Check for obstructions in the flue outlet.
    3. Ensure gas line, meter, and/or regulator is sized properly.
    4. Ensure gas type and pressure is correct.
    5. Bleed all air from gas lines.
    6. Ensure proper Rinnai venting material was installed.
    7. Ensure condensation collar was installed properly.
    8. Ensure vent length is within limits.
    9. Verify dip switches are set properly.
    10. Ensure appliance is properly grounded.
    11. Disconnect keypad.
    12. Disconnect EZConnect or MSA controls to isolate the problem. Replace if necessary.
    13. Check power supply for loose connections.
    14. Check power supply for proper voltage and voltage drops.
    15. Ensure flame rod wire is connected.
    16. Check flame rod for carbon build-up.
    17. Disconnect and reconnect all wiring harnesses on unit and PC board.
    18. Check for DC shorts at components.
    19. Check gas solenoid valves for open or short circuits.
    20. Remove burner plate and inspect burner surface for condensation or debris.

    Replacement Parts

    Error Code – 14

    FAULT = Thermal Fuse

    Error Code Solutions

    1. Check gas type of unit and ensure it matches gas type being used.
    2. Check for restrictions in air flow around unit and vent terminal.
    3. Check for low water flow in a circulating system causing short-cycling.
    4. Ensure dip switches are set to the proper position.
    5. Check for foreign materials in combustion chamber and/or exhaust piping.
    6. Check heat exchanger for cracks and/or separations.
    7. Check heat exchanger surface for hot spots which indicate blockage due to scale build-up.
    8. Refer to instructions in manual for flushing heat exchanger.
    9. Measure resistance of safety circuit.
    10. Ensure high fire and low fire manifold pressure is correct.
    11. Check for improper conversion of product.

    Replacement Parts

    Error Code – 16

    FAULT = Over Temperature Warning

    Error Code Solutions

    1. Check for restrictions in air flow around unit and vent terminal.
    2. Check for low water flow in a circulating system causing short-cycling.
    3. Check for foreign materials in combustion chamber and/or exhaust piping.
    4. Check for clogged heat exchanger. Flush system if necessary.

    Replacement Parts

    Error Code – 19

    FAULT = Electrical Grounding

    Error Code Solutions

    1. Check all components for electrical short.

    Replacement Parts

    Error Code – 25

    FAULT = Condensate Trap is full

    Error Code Solutions

    1. Inspect condensate drain line for blockage.
    2. Inspect condensate trap and tank inside cabinet for blockage.
    3. Ensure condensate line has an air gap between the unit and drain line leaving the water heater.
    4. Check sensor wiring harness for loose, broken or damaged connections from sensor back to PC board.
    5. If condensate tank is draining and the unit is still throwing a code 25 replace condensate tank with sensor.

    Replacement Parts

    Error Code – 31

    FAULT = Burner Thermocouple

    Error Code Solutions

    1. Check low/high fire manifold pressures for proper settings.
    2. Verify all dip switches are set to the proper position on the PC board.
    3. Measure milli‐volt (mV) reading of burner thermocouple. The thermocouple milli‐volt range should be between 20 to 27 mV under normal combustion.
    4. Replace thermocouple.

    Replacement Parts

    Error Code – 32

    FAULT = Outgoing Water Temperature Sensor Fault

    Error Code Solutions

    1. Check sensor wiring for damage.
    2. Measure resistance of sensor.
    3. Clean sensor of scale build-up.
    4. Replace sensor.

    Replacement Parts

    Error Code – 33

    FAULT = Heat Exchanger Outgoing Temperature Sensor Fault

    Error Code Solutions

    1. Check sensor wiring for damage.
    2. Measure resistance of sensor.
    3. Clean sensor of scale build-up.
    4. Replace sensor.

    Replacement Parts

    Error Code – 34

    FAULT = Combustion Air Temperature Sensor Fault

    Error Code Solutions

    1. Check for restrictions in air flow around unit and vent terminal.
    2. Check sensor wiring for damage.
    3. Measure resistance of sensor.
    4. Clean sensor of scale build-up.
    5. Ensure fan blade is tight on motor shaft and is in good condition.
    6. Replace sensor.

    Replacement Parts

    Error Code – 41

    FAULT = Freeze Protection Sensor for External Units

    Error Code Solutions

    1. Check sensor wiring harness for loose, broken or damaged connections from sensor back to PC board.
    2. Ensure sensor is open to outside air and not covered with insulation.
    3. With water supply still isolated and sensor removed from unit, check the resistance readings of this component using a volt/ohm meter capable of reading 20K ohms. Typical resistance values are 11.4 – 14K ohms at 59 degrees ⁰F, 6.4 – 7.7K ohms at 86⁰F, 3.6 – 4.5K ohms at 113⁰F, 2.2 – 2.7K at 140 ⁰F or 0.6 – 0.8K at 221 ⁰F.
    4. If sensor readings are correct re‐install this component ensuring the small O‐ring is still intact in sensor well before installation. Place a small amount of grease or lubricant on the O‐ring to prevent damaging it during installation. Turn water supply back on and check for leaks around this component. Next re‐fire the unit to see if you still get a code 41. If so, replace the sensor.

    Replacement Parts

    Error Code – 51

    FAULT = Inlet Water Temperature Sensor

    Error Code Solutions

    1. Check sensor wiring harness for loose, broken or damaged connections from sensor back to PC board.
    2. Turn off water supply to water heater and drain system down. With no water left in hot water supply lines remove the sensor and check it for scale build up. Clean off any substance found on this component.
    3. With water supply still isolated and sensor removed from unit, check the resistance readings of this component using a volt/ohm meter capable of reading 20K ohms. Typical resistance values are 11.4 – 14K ohms at 59 degrees ⁰F, 6.4 – 7.7K ohms at 86⁰F, 3.6 – 4.5K ohms at 113⁰F, 2.2 – 2.7K at 140 ⁰F or 0.6 – 0.8K at 221 ⁰F.
    4. If sensor readings are correct re‐install this component ensuring the small O‐ring is still intact in sensor well before installation. Place a small amount of grease or lubricant on the O‐ring to prevent damaging it during installation. Turn water supply back on and check for leaks around this component. Next re‐fire the unit to see if you still get a code 51. If so, replace the sensor.

    Replacement Parts

    Error Code – 52

    FAULT = Modulating Solenoid Valve Signal Abnormal

    Error Code Solutions

    1. Check modulating gas solenoid valve wiring harness for loose or damaged terminals.
    2. Measure resistance of valve coil.
    3. Check voltage to the POV valve while unit is trying to fire. If you have the proper voltage but keep getting an error code proceed to the next item.
    4. If code 52 still appears after performing the above inspection replace the PC board.

    Replacement Parts

    Error Code – 57

    FAULT = Burner Overheat Bi‐metal Switch

    Error Code Solutions

    1. Check burner overheat bi‐metal switch wiring harness for loose, broken or damaged connections from sensor back to PC board.
    2. Verity unit is connected to the proper type gas.
    3. Verify low/high fire manifold pressures are set properly.
    4. Clean sensor.
    5. If unit was ever converted from one gas type to another, verify the conversion process was preform per the manufacturer’s instructions and all pressures and dip switch were set to match the gas type unit was converted too.
    6. Replace sensor

    Replacement Parts

    Error Code – 58

    FAULT = Secondary Heat Exchanger Sensor

    Error Code Solutions

    1. Check sensor wiring harness for loose, broken or damaged connections from sensor back to PC board.
    2. This code indicates a scale build‐up inside the secondary heat exchanger and it needs to be flushed to prevent damage.
    3. Descale unit with a tankless flush

    Replacement Parts

    Error Code – 61

    FAULT = Combustion Fan Failure

    Error Code Solutions

    NOTE: Before servicing fan motor turn off power supply to the unit.

    1. Check sensor wiring harness for loose, broken or damaged connections from sensor back to PC board.
    2. Remove fan motor with power supply to product turned off. Inspect blower wheel to ensure it turns freely.
    3. Check fan housing for debris that could prevent the fan wheel from turning.
    4. Measure fan motor winding resistance, see technical data sheet behind front cover or in service manual for proper resistance readings. If windings are open replace motor.
    5. If motor windings are within specifications and fan motor turns freely, replace PC board.

    Replacement Parts

    Error Code – 65

    FAULT = Water Flow Control Fault

    Error Code Solutions

    1. The water flow control valve has failed to close during the bath fill function. Immediately turn off the water and discontinue the bath fill function.
    2. Check wiring harness to the water flow servo for loose, broken or damaged connections from servo back to PC board.
    3. Turn off the power to the water heater and then reapply to see if code resets.
    4. Contact a qualified or licensed contractor to service the appliance.
    5. Replace water flow control servo.

    Replacement Parts

    • Water flow control servo

    Error Code – 70

    FAULT = PC Board Fault

    Error Code Solutions

    1. Check all wiring harness at the connection to the PC board to ensure they are not loose, broken or damaged.
    2. Check all dip switches to ensure they are set to the proper position.
    3. Replace the PC Board.

    Replacement Parts

    Error Code – 71

    FAULT = SV0, SV1, SV2, and SV3 Solenoid Valve Circuit Fault

    Error Code Solutions

    1. Check wiring harness to all solenoids for damage and/or loose connections.
    2. Measure resistance of each solenoid valve coil.
    3. Check for moisture in plastic tubing on internal units from bottom of combustion box back to gas valve. If moisture is found in this tube replace gas valve. In addition; remove burner manifold and burner assembly to determine what is causing the moisture. Look for a leaking heat exchanger or condensation coming from the vent system.
    4. If you are still getting a code 71 replace the gas control valve.
    5. Replace PC board

    Replacement Parts

    Error Code – 72

    FAULT = Flame Sensing Device Fault

    Error Code Solutions

    1. Ensure flame rod is touching flame when unit fires.
    2. Check all wiring to flame rod for damage.
    3. Remove flame rod and check for carbon build-up; clean with sand paper.
    4. Check inside burner chamber for any foreign material blocking flame at flame rod.
    5. Measure micro amp output of sensor circuit with flame present.
    6. Replace flame rod.

    Replacement Parts

    Error Code – 73

    FAULT = Burner Thermocouple Fault

    Error Code Solutions

    1. Check wiring harness at burner thermocouple back to PC board for loose, broken or damaged wiring or connections.
    2. Verify all dip settings are set to the proper alitiube per the tech sheet found under the front panel of your unit.
    3. Confirm low/high fire manifold gas pressures are set to factory specification per alitiude unit is installed at. Manifold gas pressure settings and directions can be found on the tech sheet under front panel of the unit.
    4. Replace burner thermocouple. If code reappears after replacing this component replace PC board.

    Replacement Parts

    Error Code – 79

    FAULT = Water Leakage Detected

    Error Code Solutions

    1. Check wiring harness at leak detector for loose, broken or damaged wiring or connections.
    2. Check the heat exchanger and all piping inside the unit for leaks.
    3. If no leaks are found inspect inside of cabinet for signs of water pooling on bottom pan of water heater. Wipe or blow out any water found in cabinet. Dry off leak sensor and restart unit.
    4. If no water is found in cabinet unplug sensor and start water heater. If unit operates with sensor unplugged replace sensor and screw.

    Replacement Parts

    • Water Leak Sensor

    Error Code – NO CODE

    FAULT = Nothing happens when water flow is activated

    Error Code Solutions

    1. Clean water inlet filter to water heater.
    2. On new installations ensure the hot/cold water lines are not reversed.
    3. Ensure you have the minimum flow rate required to fire the unit.
    4. Ensure water flow control turbine spins freely.
    5. Measure the resistance of the water flow control sensor, see technical data sheet behind front cover of unit for proper readings.
    6. Check for bleed overs – isolate unit from building by turning off hot water line to building. Next isolate the circulation system if present. Open your pressure relief valve; if water is flowing, there is a bleed over in your plumbing system.

    Replacement Parts

    • Not Applicable

    Error Code – LC, LC0-LC9

    FAULT = Scale Build-up in Heat Exchanger

    Error Code Solutions

    Note – when checking maintenance code history, “00” is substituted for “LC”

    1. Before servicing unit be sure to disconnect power supply.
    2. Flush heat exchanger.
    3. NOTE: The LC code is the only error code that will allow the unit to keep running. The display will alternate between the LC code and the temperature setting. The controller will continue to beep. The LC code will reset if power is turned off and then on.
    4. On newer Rinnai tankless systems there is a shutdown feature built into the product to prevent damage caused by the unit scaling up. To temporarily operate the water heater until it can be flushed push the on/off button on the temperature controller 5 times. This will give you 70 hours of service before anther LC code.

    Replacement Parts

    Error Code – FF

    FAULT = Indicates a serviceman has serviced product

    Error Code Solutions

    This code indicates a service provider performed maintenance or repair. The serviceman will enter the
    following code FF after making repairs to the product. That flags the system indicating all codes after the
    FF took place after he made his repairs. You can enter the FF code by; pressing the up, down and
    ON/OFF buttons simultaneously.

    Replacement Parts

    • Not Applicable

    Error Code – NO WIFI

    FAULT = WiFi not working

    Error Code Solutions

    1. Clean thCheck Wifi module and connections.
    2. Replace Wifi or install WiFi system

    Replacement Parts

    You have found Rinnai tankless error codes but if you are looking for other models or brands we have them all below.

    We have a full list of all tankless error codes and the corresponding parts needed to fix or repair your tankless or combi boiler systems. Check them out here.