Rinnai Error Code 14: Thermal Fuse
Warning: Your Rinnai water heater has detected a thermal fuse issue. It's safe to use other appliances, but call a professional for repair soon.
How to Fix Rinnai Code 14
- Check the reset button on your water heater. If it's tripped, press it once to reset. If it trips again, call a professional.
- If your water heater has a dial for temperature, make sure it's not set too high (around 120°F is recommended).
- If you're comfortable doing so, visually inspect the heating elements for any signs of damage or buildup. If you see any issues, call a professional.
How to Reset Rinnai Code 14
- 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 14 Mean?
Error code 14 on your Rinnai water heater indicates a problem with the thermal fuse, a safety device that cuts power to the heating elements when temperatures get too high. This is a common issue and usually user-fixable, but it's important to address it promptly to prevent further damage or system lockout.
Common Causes
- The thermal fuse has blown due to excessive heat, often caused by a faulty heating element or high water temperature.
- The temperature sensor is sending incorrect data to the control board, triggering the thermal fuse.
- The control board itself may be faulty, sending incorrect signals to the thermal fuse.
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| The reset button is tripped | Press the reset button once | The water heater should restart |
| The water heater doesn't restart after resetting | Measure the resistance of the thermal fuse using a multimeter | Infinite resistance (open circuit) indicates a blown fuse |
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 |
|---|---|---|---|
| Thermal Fuse | RIN-101021200 | — | Find Part |
| Heating Element | RIN-101021100 | — | Find Part |
Related Codes on Same Models
Other codes that affect the same Rinnai model families as 14.
| Code | Description | Severity |
|---|---|---|
| 02 | Stagnant Water Detection | Warning |
| 10 | Air Supply/Exhaust Blockage | Warning |
| 11 | No Ignition | Warning |
| 12 | Flame Failure | Warning |
| 16 | Over-Temperature | Warning |
| 19 | Electrical Grounding | Warning |
| 25 | Condensate Overflow | Warning |
| 29 | Condensate Neutralizer | Warning |
| 31 | Inlet Thermistor Failure | Warning |
| 34 | Combustion Air Thermistor | Warning |