Navien Error Code E012: Flame Loss

Severity
Warning
Type
digital display
Where to look
front panel
Estimated repair cost: $100 — $250 (parts + labor)
Warning: Your Navien boiler has experienced a flame loss, which could lead to system damage if not addressed promptly. It's safe to troubleshoot, but call a professional if needed.

How to Fix Navien Code E012

  1. Check if the reset button (if present) has tripped. Press it once to reset the boiler.
  2. Ensure the boiler's power switch is ON and the boiler is in heating mode.
  3. Inspect the gas supply valve to ensure it's open and gas is flowing.

How to Reset Navien Code E012

  1. Turn off the unit using the power button on the front panel.
  2. Turn off the gas supply valve.
  3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
  4. Restore power at the breaker, then open the gas valve.
  5. Turn the unit back on. If the error returns, the underlying issue needs repair.

What does E012 mean?

The E012 error on your Navien boiler indicates a flame loss issue. This could be due to a problem with the ignition system, a blockage in the combustion chamber, or an issue with the gas valve. The boiler will display this error and shut down to prevent further damage. While it's safe to check a few things, do not attempt to open the boiler or tamper with gas lines.

Affected Models

Source Documentation

ManualPageReasonAction
NFB-H Installation & Operation Manual 116 Flame Loss Check gas, venting and condensate trap.
Navien NCB-H Installation & Operation Manual 129 Flame Loss ● Clean the intake air filter. ● Ensure that the electrical cord is properly grounded.
Navien NFB-H Installation & Operation Manual 116 Flame Loss Check gas, venting and condensate trap.
Navien NFC-H Installation & Operation Manual 127 Flame loss Manual RESET
Navien NHB-H Installation & Operation Manual 119 Flame Loss Check gas, venting and condensate trap.
Navien NPF Installation & Operation Manual 125 Flame loss during combustion This error occurs when the flame detector does not operate properly. ● Check if the supply and exhaust pipes connected to the furnace are installed properly. ● If the furnace is continuously inoperable, contact Technical Support at 1-800-519-8794.

Recall Notices

Navien Tankless Water Heaters and Combination Boilers Recalled Due to Carbon Monoxide Hazard 19-027

LP gas conversion kits can cause units to produce excessive carbon monoxide.

View official notice

Replacement Parts

PartOEM NumberEst. Cost
Igniter 400-00014-00
Gas Valve 400-00018-00
Flame Sensor 400-00015-00

Related Codes on Same Models

CodeDescriptionSeverity
E001 Ignition Failure Warning
E003 Abnormal Ignition Warning
E004 False Flame Detection 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
E109 Fan Motor Speed Low Warning