Rinnai Error Code 70: PCB Failure
Warning: Your Rinnai water heater is experiencing a PCB failure, which has caused it to shut down. This is not an immediate safety risk, but it requires professional repair.
How to Fix Rinnai Code 70
- Step 1: Turn off the power to the water heater at the circuit breaker to prevent any further damage.
- Step 2: Do not attempt to open the water heater or perform any repairs yourself. This can void your warranty and may cause further damage or injury.
- Step 3: Contact a licensed Rinnai technician to diagnose and repair the PCB failure.
How to Reset Rinnai Code 70
- 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 70 Mean?
The error code 70 on your Rinnai water heater indicates a failure of the Printed Circuit Board (PCB), which is a critical component of the unit's control system. When the PCB fails, it can cause the water heater to shut down to prevent any further damage. This error is not typically caused by user error and usually requires a professional technician to diagnose and repair.
Common Causes
- Wear and tear over time
- Power surges or fluctuations
- Manufacturer defect
- Moisture or water damage
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| Water heater is not producing hot water | Check the digital display for the error code 70 | Error code 70 should be displayed |
| Power is still connected to the water heater | Check the circuit breaker to ensure it has not tripped | Circuit breaker should be in the ON position |
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 |
|---|---|---|---|
| PCB Assembly | RIN-120012000 | — | Find Part |
| Thermal Cutoff Switch | RIN-120012001 | — | Find Part |
Related Codes on Same Models
Other codes that affect the same Rinnai model families as 70.
| 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 |