Rinnai Water Heaters Error Codes

Code 02

Water heater shuts down shortly after ignition attempt; display shows Code 02

Flame Failure / Flame Loss

Code 03

Water heater stops during operation and displays Code 03; unit may restart after some time

Power Interruption During Operation

Code 05

Water heater shuts down and displays Code 05; unit may feel very hot to the touch around the heat exchanger area

Air Intake or Exhaust Blockage / Overheat

Code 07

Unit attempts to start but shuts down with Code 07; no sustained flame

Ignition Failure

Code 10

Water heater displays Code 10 and will not operate; often after installation or vent changes

Air Supply or Exhaust Blockage / Improper Venting

Code 11

Unit will not ignite; display shows Code 11 shortly after a demand for hot water

No Ignition / Ignition Failure

Code 12

Burner lights briefly then shuts off; display shows Code 12 (flame failure during operation)

Flame Failure During Operation

Code 14

Unit shuts down with Code 14; outer case may feel warm and fan may run after shutdown

Thermal Fuse / Overheat Cutoff Activation

Code 16

Unit shuts down during long hot water use and displays Code 16 (over-temperature warning)

Outlet Water Over-Temperature

Code 19

Intermittent shutdowns with Code 19; unit may restart after cycling power

Electrical Grounding / Power Supply Error

Code 25

Unit shuts down and displays Code 25; may be accompanied by a fuel smell or abnormal combustion noise

Condensate or Drain Blockage / Abnormal Combustion

Code 29

Unit displays Code 29 and may shut down during operation, especially in cold weather

Condensate Drain Blockage / Neutralizer Issue (Condensing Models)

Code 31

Unit will not operate and displays Code 31

Inlet Thermistor Fault

Code 32

Unit displays Code 32 and will not run

Outlet Thermistor Fault

Code 33

Unit displays Code 33 and shuts down

Heat Exchanger Thermistor Fault

Code 34

Unit displays Code 34; may occur during windy conditions or vent issues

Combustion Air / Flue Thermistor Fault

Code 35

Unit displays Code 35 and will not operate

Improper Thermistor Connection / Thermistor Circuit Error

Code 41

Unit displays Code 41 and will not start

Flow Sensor Fault

Code 51

Unit displays Code 51 and will not operate

Gas Control Valve Fault

Code 52

Unit displays Code 52; ignition may be erratic

Modulating Gas Valve Signal Fault

Code 61

Unit displays Code 61 and fan may not run or runs erratically

Combustion Fan Motor Fault

Code 65

Unit displays Code 65 and may not respond correctly to water flow changes

Water Control Valve Fault

Code 71

Unit displays Code 71 and will not operate

Solenoid Valve Circuit Fault

Code 72

Unit displays Code 72; ignition may start but flame sensing is unreliable

Flame Sensing Circuit Fault

Code 73

Unit displays Code 73 and will not operate

Communication Error Between Components / Parameter Setting Error

Code 79

Unit displays Code 79 and shuts down

Fan Motor or Fan Speed Feedback Fault

Code 90

Unit displays Code 90; may be associated with poor combustion or sooting

Abnormal Combustion / Combustion Performance Error

Code 92

Unit displays Code 92 and may not modulate correctly

Combustion Fan Speed / Feedback Error

Code 99

Unit displays Code 99 and shuts down; may be intermittent

Flame Loss / Flame Detection Error

Symptom

Condensate water dripping from vent joints or around the unit

Condensate Leakage from Venting

Symptom

Exhaust smell or suspected carbon monoxide near the unit or in the home

Flue Gas Spillage / Venting Failure

Symptom

No hot water at any fixture; unit does not attempt to start (no fan or ignition sound)

No Power / Control Circuit Inactive

Symptom

No hot water at some fixtures but other fixtures get hot water normally

Plumbing Crossover or Local Mixing Issue

Symptom

Remote controller does not power on or display is blank, but unit has power

Remote Controller Power / Communication Failure

Symptom

Remote controller shows power but cannot change temperature or turn unit on/off

Remote Controller Input / Lockout

Symptom

Strong gas smell near the water heater, with or without operation

Gas Leak / Combustible Gas Odor

Symptom

Unit cycles on and off rapidly when a small amount of hot water is used (e.g., handwashing)

Short Cycling at Low Flow

Symptom

Unit freezes or is damaged after cold weather; no water flow or visible cracks

Freeze Damage / Frozen Heat Exchanger

Symptom

Unit is very noisy; loud fan or vibration sounds when running

Excessive Vibration / Fan Noise

Symptom

Unit shuts off when multiple fixtures are used; hot water stops unexpectedly under high demand

Overload / Capacity Exceeded

Symptom

Water heater is leaking from the pressure relief valve discharge pipe

Relief Valve Discharge / Overpressure

Symptom

Water heater is leaking water from the bottom of the unit

Internal Water Leak

Symptom

Water heater makes loud banging or popping noises during operation

Scale Buildup / Combustion Noise

Symptom

Water is warm but not hot enough, even with temperature set high on the controller

Insufficient Heating / Under-Temperature

Symptom

Water temperature fluctuates between hot and cold during a shower

Temperature Fluctuation / Hunting