Rinnai Error Code 12: Flame Failure
Warning: Your Rinnai water heater has experienced a flame failure, which could lead to water not heating properly. No immediate danger, but call a pro soon.
How to Fix Rinnai Code 12
- Check if the power is on and the circuit breaker hasn't tripped.
- Ensure the gas supply valve is fully open.
- If you're comfortable, reset the water heater by turning off the power, waiting 10 minutes, then turning it back on.
How to Reset Rinnai Code 12
- 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.
Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.
What Does Rinnai Error Code 12 Mean?
The Rinnai 12 error code indicates that your water heater's flame has gone out, preventing it from heating water. This could be due to a few reasons, but don't worry, it's usually an easy fix. The most common cause is a problem with the ignition system, but it could also be a gas supply issue or a faulty temperature sensor.
Common Causes
- Faulty ignition system (spark module or igniter)
- Low gas supply pressure
- Defective temperature sensor
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| Water heater is not heating water | Measure gas supply pressure at the gas valve using a manometer | Between 7" to 11" W.C. (depending on your model) |
| Gas pressure is within range | Inspect the spark module and igniter for any visible damage or soot | No visible damage or excessive soot |
Applicable Rinnai Models
- CU(gas)
- HE(dual_fuel)
- HE++ Series(gas)
- I-SERIES(gas)
- NCB(gas)
- NPE(gas)
- RE(gas)
- REP(gas)
- RL(gas)
- RU(gas)
- RUCS(gas)
- RX(gas)
- RXP(gas)
- Rinnai NCB Series(gas)
- Rinnai NPE Series(gas)
- Rinnai R Series(gas)
- Rinnai RL Series(natural_gas)
- Rinnai RU Series(natural_gas)
- Rinnai RUR Series(gas)
- Rinnai VSP(gas)
- V(gas)
Replacement Parts
| Part | OEM Number | Est. Cost | Where to Buy |
|---|---|---|---|
| Spark Module | RIN-100152000 | — | Find Part |
| Igniter | RIN-100152001 | — | Find Part |
Related Codes on Same Models
Other codes that affect the same Rinnai model families as 12.
| Code | Description | Severity |
|---|---|---|
| 02 | Stagnant Water Detection | Warning |
| 10 | Air Supply/Exhaust Blockage | Warning |
| 11 | No Ignition | 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 |
| 32 | Outlet Thermistor Failure | Warning |