In case of Emergency

Rinnai error code 2: No burner operation during freeze protection mode 

• Call a licensed plumber

Rinnai error code 3: Power interruption during Bath Fill (Water will not flow when power returns). 

• Turn off all hot water taps. 
• Press ON/OFF twice. 
  

Rinnai error code 10: Air Supply or Exhaust Blockage 

• Ensure Rinnai approved venting materials is being used.
• Check that nothing is blocking the flue inlet or exhaust. 
• Check all vent components for proper connections. 
• For non-condensing models, ensure condensation collar was installed correctly. 
• Verify dip switches are set properly. 

Other possible causes, which will require a licensed plumber:

• Ensure vent length is within limits.
• Check fan for blockage.
• Check the fins in the heat exchanger.

Rinnai error code 11: No Ignition

• Check that the gas is turned on at the water heater, gas meter, or cylinder. 
• Ensure gas type and pressure is correct.
• Verify dip switches are set properly.

Other possible causes, which will require a licensed plumber:

• Ensure gas line, meter, and/or regulator is sized properly.
• Bleed all air from gas lines. 
• Ensure appliance is properly grounded.
• Disconnect EZConnect or MSA controls to isolate the problem.
• Ensure igniter is operational.
• Check igniter wiring harness for damage.
• Check gas solenoid valves for open or short circuits.
• Remove burner cover and ensure all burners are properly seated.
• Remove burner plate and inspect burner surface for condensation or debris. 
• If flame is visible, check the flame rod circuit. 

Rinnai error code 12: Flame Failure 

• Check that the gas is turned on at the water heater and gas meter. 
• Check for obstructions in the flue outlet. 
• Ensure gas type and pressure is correct.
• Ensure proper Rinnai venting material was installed. 
• For non-condensing models, ensure condensation collar was installed properly. 
• Verify dip switches are set properly.

Other possible causes which will require a licensed plumber:

• Ensure gas line, meter, and/or regulator is sized properly. 
• Bleed all air from gas lines.
• Ensure vent length is within limits.
• Ensure appliance is properly grounded.
• Disconnect keypad. Disconnect EZConnect or MSA controls to isolate the problem.
• Check power supply for loose connections.
• Check power supply for proper voltage and voltage drops.
• Ensure flame rod wire is connected.
• Ensure flame rod is in proper position (wire should connect at 6 o’clock position). 
• Remove flame rod and check for carbon build-up; clean with sand paper or emery cloth. 
• Disconnect and reconnect all wiring harnesses on unit and PC board.
• Check all components for electrical short.
• Check gas solenoid valves for open or short circuits.
• Remove burner plate and inspect burner surface for condensation or debris.
• Check the ground wire for the PC board. 

Rinnai error code 14: Thermal Fuse

• Check gas type of unit and ensure it matches gas type being used. 
• Check for restrictions in air flow around unit and vent terminal.
• Ensure dip switches are set to the proper position. 

Other possible causes, which will require a licensed plumber

• Check for low water flow in a circulating system causing short-cycling. 
• Check for foreign materials in combustion chamber and/or exhaust piping.
• Check heat exchanger for cracks and/or separations.
• Check heat exchanger surface for hot spots which indicate blockage due to scale build-up.
• Refer to instructions in manual for flushing heat exchanger. Hard water must be treated to prevent scale build up or damage to the heat exchanger. 
• Measure resistance of safety circuit.
• Ensure high fire and low fire manifold pressure is correct. 
• Check for improper conversion of product. 

Rinnai error code 16: Over Temperature Warning 

• Check for restrictions in the intake and exhaust pipe system.

Other possible causes, which will require a licensed plumber

• Check for low water flow in a circulating system causing short-cycling. 
• Check for foreign materials in combustion chamber and/or exhaust piping. 
• Check for blockage in the heat exchanger. 

Rinnai error code 19: Electrical Grounding
Will require a licensed plumber

• Check all components for electrical short. 

Rinnai error code 31: Burner Sensor Error  (ONLY FOR VB INDOOR MODELS )
Will require a licensed plumber

• Measure resistance of sensor.
• Replace sensor. 

Rinnai error code 32: Outgoing Water Temperature Sensor
Will require a licensed plumber

• Check sensor wiring for damage. 
• Measure resistance of sensor. 
• Clean sensor of scale build-up. 
• Replace sensor. 

Rinnai error code 33: Heat Exchanger Outgoing Temperature Sensor
Will require a licensed plumber

• Check sensor wiring to be sure it has not been short-circuited. 
• Measure resistance of sensor.
• Clean sensor of scale build-up.
• Replace sensor. 

Rinnai error code 34: Combustion Air Temperature Sensor (ONLY FOR INDOOR NON-CONDENSING MODELS EXCEPT R98LSi)

• Check for restrictions in the intake and exhaust system. 

Other possible causes, which will require a licensed plumber

• Check sensor wiring for damage.
• Measure resistance of sensor.
• Clean sensor of scale build-up. 
• Check the fan blade to be sure it is tight on motor shaft and is in good condition. 
• Replace sensor. 

Rinnai error code 41: Outside temperature thermistor (outdoor models only)
Will require a licensed plumber

• Check sensor wiring for damage. 
• Measure resistance of sensor. 
• Clean sensor of scale build-up. 
• Replace Sensor. 

Rinnai error code 51: Inlet water temperature thermistor (RL94 only)
Will require a licensed plumber

• Check sensor wiring for damage. 
• Measure resistance of sensor. 
• Clean sensor of scale build-up. 
• Replace Sensor. 

Rinnai error code 52: Modulating Solenoid Valve Signal Abnormal
Will require a licensed plumber

• Check modulating gas solenoid valve wiring harness for loose or damaged terminals. 
• Measure resistance of valve coil.

Rinnai error code 57: Burner
Will require a licensed plumber

• Inspect and clean burners. 

Rinnai error code 61: Combustion Fan Failure
Will require a licensed plumber

• Ensure fan will turn freely.
• Check wiring harness to motor for damaged and/or loose connections. 
• Measure resistance of motor winding.
• Check for proper voltage from PC board. 

Rinnai error code 65: Water Flow Control
Will require a licensed plumber

• 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. 
• Contact a state qualified or licensed contractor to service the appliance. 

Rinnai error code 70: PC Board

• Check PC board DIP switches for correct position.

Other possible causes, which will require a licensed plumber

• Check the connection harness at the connection on the PC board. 
• Replace PC board. 

Rinnai error code 71: Solenoid Valve Circuit
Will require a licensed plumber

• For non-condensing, check wiring harness to all solenoids for damage and/or loose connections. 
• Measure resistance of each solenoid valve coil. 

Rinnai error code 72: Flame Sensing Device
Will require a licensed plumber

• Verify flame rod is touching flame when unit fires.
• Check all wiring to flame rod.
• Remove flame rod and check for carbon build-up; clean with sand paper or emery cloth.
• Check inside burner chamber for any foreign material blocking flame at flame rod. 
• Measure micro amp output of sensor circuit with flame present.
• Replace flame rod. 

Rinnai error code 73: Burner Sensor Circuit (ONLY FOR VB INDOOR MODELS)
Will require a licensed plumber

• Check sensor wiring and PC board to be sure they have not been damaged. 
• Replace sensor. 

Rinnai error code 79: Water Leak Detected (Water has been detected at the bottom of the unit)

• Turn off water supply. 
• Check plumbing. 
• Call a licensed plumber.

Rinnai error code LC, LC#, LC0, LC1, LC2…: Scale Build-up in Heat Exchanger
Will require a licensed plumber

• Flush heat exchanger. Refer to instructions in manual. For older units this is not recommended  as it will remove internal deposits that may have corroded the pipe lining and possibly cause a leak.
• Replace heat exchanger.
• For locations known to have hard water it is highly recommended to utilize a water softener to prevent scale build up or damage to the heat exchanger.
• NOTE: The LC code is the only 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. 

Rinnai error code FF#: Maintenance performed 

• Indicates a licensed professional performed maintenance or corrected an issue. 

No code: Nothing happens when water flow is activated. 

• On controller, verify if unit is sensing flow. If not then check the items below. If unit is sensing flow then check the heat exchanger and outlet thermistors.
• Clean inlet water supply filter.
• On new installations ensure hot and cold water lines are not reversed. 
• Check for cold to hot cross over. Isolate circulating system if present. Turn off cold water to the unit, open pressure relief valve; if water continues to flow, there is bleed over in your plumbing. 
• Verify you have at least the minimum flow rate required to fire unit.

Other possible causes, which will require a licensed plumber

• Verify turbine spins freely.
• Measure the resistance of the water flow control sensor.
• If the display is blank and clicking is coming from the unit, disconnect the water flow servo motor (RD, BL, BR, GY, YL). If the display come on then replace the water flow servo motor. 

Rheem error code 00: 1 Hour continuous combustion

• Close all hot water taps to reset unit.
• Turn off, or remove circulation pumps (unit is not designed for continuous operation with circulation systems).

Rheem error code 05: Imperfect Combustion Alarm

Will require a licensed plumber

• Clean air inlet filter.
• Clean combustion air fan.
• Clean heat exchanger fins.
• Check for adequate combustion air ventilation openings and clean if necessary.
• Check vent system for partial blockage and correct as necessary.

Rheem error code 10: Air Supply or Exhaust Blockage

• Check all vent components for proper connections.
• Check that nothing is blocking the flue inlet or exhaust.
• Ensure proper venting materials were used.
• Ensure condensation collar was installed correctly.

Other possible causes, which will require a licensed plumber:

• Ensure heat exchanger fins, fan, and air intake are not blocked.

Rheem error code 11: No Ignition

• Ensure you have gas to the appliance.
• Ensure gas type and pressure is correct.

Other possible causes, which will require a licensed plumber:

• Bleed all air from gas lines.
• Ensure gas line, meter, and regulator are sized properly.
• Ensure appliance is properly grounded.
• Check gas solenoid valves for open or short circuits.
• Ensure igniter is operational.
• Check igniter wiring harness for damage.

Rheem error code 12: Flame Failure

• Ensure you have gas to the appliance.
• Ensure gas type and pressure is correct.

Other possible causes, which will require a licensed plumber

• Bleed all air from gas lines.
• Ensure flame rod wire is connected.
• Check flame rod for carbon build-up.
• Ensure gas line, meter, and regulator are sized properly.
• Ensure appliance is properly grounded.
• Check gas solenoid valves for open or short circuits.
• Check power supply for loose connections.
• Check power supply for proper voltage and voltage drops.
• Disconnect remote control.
• Disconnect and re-connect all wiring harnesses on unit and PC board.
• Ensure proper venting material was installed.
• Ensure condensation collar was installed properly.
• Ensure maximum vertical vent length does not exceed allowable limits.
• Ensure maximum horizontal vent length does not exceed allowable limits.

Rheem error code 14: Overheat Wrap Fault

Will require a licensed plumber

• Ensure high fire and low fire manifold pressure are correct.
• Check gas type of unit and ensure it matches gas type being used.
• Check heat exchanger for cracks and/or separations.
• Ohm out safety circuit.
• Check for improper conversion of product.
• Check for restrictions in air flow around unit and vent terminal.
• Check for a foreign materials in combustion chamber and/or exhaust piping.

Rheem error code 15: Boiling Safety Device

Will require a licensed plumber

• Check for closed water heater inlet valve or restrictions in cold water inlet pipe (must be fully open).
• Check for clogged heat exchanger (scale buildup).
• On commercial water heater, lower setpoint temperature below 180F at high altitude.

Rheem error code 16: Over Temperature Warning Check for clogged heat exchanger.

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

Other possible causes, which will require a licensed plumber:

• Check for a foreign materials in combustion chamber and/or exhaust piping.

Rheem error code 21: Malfunction of Air Intake Filter Switch

• Make sure air filter door is properly seated.
• Make sure front panel is properly installed.
  

Rheem error code 24: Malfunction of Operational Switch

• Press max button on PCB to reset.
• Press min button on PCB to reset.

Other possible causes, which will require a licensed plumber:

• Replace PCB
  

Rheem error code 29: Heat Exchanger Outlet Temp. Too Low

Will require a licensed plumber

• Clean heat exchanger air inlet
  

Rheem error code 31: Water Inlet Temperature Sensor Fault

Will require a licensed plumber

• Check sensor wiring for damage.
• Ohm out sensor
• Check and clean scale from sensor.
• Replace sensor.
  

Rheem error code 33: Outgoing Water

Will require a licensed plumber

• Temperature Sensor Fault
• Check sensor wiring for damage.
• Ohm out sensor
• Check and clean scale from sensor.
• Replace sensor.
  

Rheem error code 34: Combustion Air Temperature Sensor Fault

Will require a licensed plumber

• Check sensor wiring for damage.
• Ohm out sensor
• Check and clean scale from sensor.
• Ensure fan blade is tight on motor shaft and it is in good condition.
• Check for restrictions in air flow around unit and vent terminal.
• Replace sensor.
  

Rheem error code 35: Improper Thermistor Connections

Will require a licensed plumber

• Check that all thermistors are connected to propor connections on PCB.
  

Rheem error code 51: Gas Inlet Solenoid Valve Fault

Will require a licensed plumber

• Check gas inlet solenoid valve wiring harness for loose or damage terminals.
• Ohm out solenoid valve.
  

Rheem error code 52: Modulating Solenoid Valve Fault

Will require a licensed plumber

• Check modulating gas solenoid valve wiring harness for loose or damage terminals.
• Ohm out solenoid valve.
  

Rheem error code 61: Combustion Fan Failure

Will require a licensed plumber

• Ensure fan motor will turn freely. (Motor will operate with a small amount of restriction.)
• Check wiring harness to motor for damaged and/or loose connections.
• Ohm out motor winding.
  

Rheem error code 71: Gas Inlet Solenoid Valve Control Fault

Will require a licensed plumber

• Check gas inlet solenoid valve wiring harness for loose or damage terminals.
• Ohm out solenoid valve.
• Replace PCB
  

Rheem error code 72: Flame Sensing Device Fault

Will require a licensed plumber

• Ensure flame rod is touching flame when unit fires.
• Check inside burner chamber for any foreign material blocking flame at flame rod.
• Check all wiring to flame rod for damage.
• Check flame rod for proper voltage.
• Remove flame rod and check for carbon build-up, clean with sand paper.
• Replace flame rod.

Rheem error code 76: Communication Fault with Remote Control

• Check remote control wiring for loose or damaged connections.

Other possible causes, which will require a licensed plumber:

• Bypass remote control cable by connecting remote control directly to remote control terminals on PCB. Replace cable if found to be faulty.
• Replace remote control.
• Replace PCB.
  

Rheem error code 79: Fan Motor Current Fault

Will require a licensed plumber

• Ensure fan motor will turn freely. (Motor will operate with a small amount of restriction.)
• Check fan motor for proper voltage.
• Replace fan motor.
• Replace PCB.
  

Rheem error code 80,81: Gas Cut-off Failure

Will require a licensed plumber

• Ohm out all solenoid valves.
• Check voltage of all flame rods.
• Replace gas control valve.
  

Rheem error code 82: Gas type data failure

Will require a licensed plumber

• Program PCB for proper gas type.
  

Rheem error code 99: Blocked Flue Fault

Will require a licensed plumber

• Clean any blockage in heat exchanger, combustion fan, inlet filter, and exhaust flue.

Rheem error code No code: Nothing happens when water is flowing through unit.

• Make sure unit is connected to proper power supply and circuit breakers are on.
• Make sure power supply inlet fuses are not blown.

Other possible causes, which will require a licensed plumber:

• Clean inlet water supply filter.
• Ensure you have at least the minimum flow rate required to fire unit.
• Check for pipe dope inside water flow control turbine.
• On new installations ensure hot and cold water lines are not crossed.
• Check for bleed over. (Close cold water supply valve to water heater. Open hot water taps at fixtures. If water flows steady from hot water taps, there is a bleed over in the system.)