Flame loss: the burner lit and then lost its flame.
Navien E012 is flame loss: the burner lit, then the flame went out. The chart says to clean the intake air filter and to make sure the cord is grounded. E003 is the burner that never lit. E110 is abnormal air pressure and also names that filter, plus a blocked exhaust pipe.
Likely causes
- Intake air filter clogged
- Electrical cord not properly grounded
Safe checks for E012
- Turn the water heater off, disconnect power, and clean the air intake filter the way section 4.5 describes: it is at the top left behind the front cover, held by a screw, and it is washed with a toothbrush under clean running water, dried, and put back
- Confirm the cord is plugged into a grounded outlet
- Reconnect power, turn the heater on, and press Back if the code is still showing
Capacitors can hold a charge after the power is off. Safety terms.
When to call a pro
If E012 returns after the intake filter is clean and the cord is grounded, call a licensed technician or Navien Technical Support at 1-800-519-8794. This chart does not send the owner into the burner or the gas valve.
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