Navien Error Code E351: Abnormal Auto Feeder Valve
How to Fix Navien Code E351
- Step 1: Check the system pressure gauge on your Navien boiler. It should typically be between 12-15 PSI when the system is cold.
- Step 2: If the pressure is significantly below 12 PSI, try manually adding water to the system using the manual fill valve (refer to your Navien manual for its location). Slowly open the valve until the pressure reaches the desired range, then close it tightly.
- Step 3: Inspect your radiators and accessible piping for any signs of leaks (water stains, drips). If you find any leaks, try to contain them and call a qualified technician immediately.
- Step 4: If the pressure drops again quickly after adding water, or if you are uncomfortable performing these steps, contact a qualified HVAC technician to diagnose and repair the problem.
How to Reset Navien Code E351
- 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 E351 mean?
The E351 error code on your Navien boiler indicates an issue with the automatic water feeder valve. This valve is responsible for maintaining the correct water pressure inside your boiler system. When the system pressure drops (due to leaks or usage), the auto feeder valve opens to add more water and keep the system running smoothly. If the system detects an abnormal operation of this valve, it will display the E351 error and potentially shut down to prevent damage.
This error is important because low water pressure can cause the boiler to overheat, operate inefficiently, or even damage components. It's like trying to run your car with low oil – eventually, something will break. Addressing this issue promptly will help ensure your heating system operates safely and reliably.
Affected Models
- NCB-H
- NFB-H
- NFC-H
- NHB-H
- NHW-A
- NPE-A2
- NCB
- NCB
- NCB
- NPE
- NPE
- NPE
- NHB
- NHB
- NCB
- NCB
- NPE
- NPE
- NCB
- NCB
- NPE
- NCB
- NPE
- NHB
- NCB
- NPE
- NPE
- NCB
- NCB
- NPE
- NPE
- NPE
- NPE
- NHB
- NHB
- NCB
- NCB
- NPE
- NPE
- NBP
- NPE
- NPE
- NPE
- NFC
- NFC
- NCB
- NPE
- NPE
- NPE
- NCB
- NPE
- NCB
- NPE
- NPE
- NCB
- NPE
- NHB
- NPE-S
- NPN
- NPN
- NCB
- NPE
- NCB
- NPE
- NHB
- NPB
- NFC
- NFC
- NHB
- NPF
- NPF
- NPE
- NHB
Source Documentation
| Manual | Page | Reason | Action |
|---|---|---|---|
| Navien NCB-H Installation & Operation Manual | 129 | Abnormal Auto Feeder Valve | Contact technical support at 1-800-519-8794. |
| Navien NFC-H Installation & Operation Manual | 127 | Abnormal Auto feeder valve (make-up water) | Manual RESET |
| Navien NPF Installation & Operation Manual | 127 | Abnormal water fill | This error occurs when the auto water fill valve does not operate properly (when auto water fill is set). ● Check if the water valve to the furnace is open. ● If this error occurs continuously, contact Technical Support at 1-800-519-8794. |
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Auto Feeder Valve | 30014639A | — |
| Pressure Sensor | DECC200118 | — |
| Main Control Board | — | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| E001 | Ignition Failure | Warning |
| E003 | Abnormal Ignition | Warning |
| E004 | False Flame Detection | Warning |
| E012 | Flame Loss | Warning |
| E016 | Overheating | Warning |
| E030 | Exhaust Overheat Sensor | Warning |
| E031 | Inlet Thermistor Open/Short | Warning |
| E046 | Outlet Thermistor Open/Short | Warning |
| E047 | DHW Thermistor Open/Short | Warning |
| E060 | Fan Motor Abnormality | Warning |