Rinnai Error Code 34: Combustion Air Thermistor
Warning: Your Rinnai water heater is experiencing a combustion air thermistor issue, which has caused it to shut down. This is not an immediate safety risk, but it does require professional attention.
How to Fix Rinnai Code 34
- Step 1: Check if the water heater is receiving power. If not, ensure the circuit breaker is turned on.
- Step 2: Inspect the area around the water heater for any signs of damage or obstruction to the combustion air intake.
- Step 3: If the issue persists, contact a licensed HVAC technician to diagnose and repair the problem. Never attempt to open the water heater or tamper with its internal components.
How to Reset Rinnai Code 34
- Turn off the unit using the power button on the front panel.
- Turn off the gas supply valve.
- Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
- Restore power at the breaker, then open the gas valve.
- Turn the unit back on. If the error returns, the underlying issue needs repair.
What does 34 mean?
The Rinnai 34 error code indicates a problem with the combustion air thermistor, a safety component that monitors the temperature of the incoming air. When this sensor malfunctions, your water heater may shut down to prevent potential safety hazards. This issue is common in Rinnai water heaters and can be caused by a faulty sensor, improper installation, or damage from environmental factors.
Affected Models
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Combustion Air Thermistor | RIN-101464000 | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| 02 | Stagnant Water Detection | Warning |
| 10 | Air Supply/Exhaust Blockage | Warning |
| 11 | No Ignition | Warning |
| 12 | Flame Failure | Warning |
| 14 | Thermal Fuse | Warning |
| 16 | Over-Temperature | Warning |
| 19 | Electrical Grounding | Warning |
| 25 | Condensate Overflow | Warning |
| 29 | Condensate Neutralizer | Warning |
| 31 | Inlet Thermistor Failure | Warning |