Navien Error Code E016: Overheating
Warning: Your Navien boiler is overheating, which could lead to system damage. Turn it off and call a professional.
How to Fix Navien Code E016
- Turn off your boiler at the main power switch
- Check if the water flow rate is normal
- If water flow is normal, call a professional HVAC technician
How to Reset Navien Code E016
- 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 Navien Error Code E016 Mean?
The E016 error on your Navien boiler indicates that the water temperature has exceeded the safe limit. This could be due to a variety of issues, such as a faulty temperature sensor, a problem with the boiler's control board, or an issue with the water flow rate. It's important to address this issue promptly to prevent further damage to your boiler.
Common Causes
- Faulty temperature sensor
- Issue with the boiler's control board
- Problem with the water flow rate
- Air in the system
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| Boiler is not producing hot water | Temperature of the water leaving the boiler | Below 180°F (82°C) |
| Air in the system is suspected | Pressure in the system | Between 10-15 PSI |
Applicable Navien Models
Source Documentation
Referenced in 6 official Navien technical manuals.
| Manual | Page | Reason | Action |
|---|---|---|---|
| NFB-H Installation & Operation Manual | 116 | Heat Exchanger Overheat | Check flow, clean system filters. |
| Navien NCB-H Installation & Operation Manual | 129 | Heat Exchanger Overheat | ● Turn off the system for at least 30 minutes, and then restart it. ● Flush the heat exchanger. |
| Navien NFB-H Installation & Operation Manual | 116 | Heat Exchanger Overheat | Check flow, clean system filters. |
| Navien NFC-H Installation & Operation Manual | 127 | Overheating of heat exchanger | Manual RESET |
| Navien NHB-H Installation & Operation Manual | 119 | Heat Exchanger Overheat | Check flow, clean system filters. |
| Navien NPF Installation & Operation Manual | 125 | Overheating of the heat exchanger | This error occurs when the overheat controller on the heat exchanger is initiated during combustion due to the heat changer overheating. ● If the furnace is continuously inoperable, contact Technical Support at 1-800-519-8794. |
Replacement Parts
| Part | OEM Number | Est. Cost | Where to Buy |
|---|---|---|---|
| Temperature Sensor | — | — | — |
| Control Board | — | — | — |
Related Codes on Same Models
Other codes that affect the same Navien model families as E016.
| Code | Description | Severity |
|---|---|---|
| E001 | Ignition Failure | Warning |
| E003 | Abnormal Ignition | Warning |
| E004 | False Flame Detection | Warning |
| E012 | Flame Loss | 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 |
| E109 | Fan Motor Speed Low | Warning |