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Navien Error Code E012: Flame loss (Combi Boiler)

Updated · by Aurora Star Tech Inc.

Navien error code E012 on a combi boiler means: Flame loss. It is also called Navien diagnostic code E012.

High severityCombi BoilerNavien NCB-H · Navien NFC-H

Homeowner? What Navien code E012 means for you

Call a technician Your combi boiler is reporting: Flame loss. The combi boiler has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Safe things you can check yourself

  • Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
  • Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
  • Look at the pressure gauge on the boiler. If it reads much lower than usual or near zero, or water is leaking, call a technician.
  • Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
  • Check that the boiler gas valve is open (handle in line with the pipe).
  • Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.
  • If only hot water is missing, check that the hot water tap is open far enough to start the heater.

Call (647) 657-2977Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Navien error code E012 mean?

The flame went out during operation after ignition. NFC-H manual lists the reset type as: Manual reset.

Applies to: Navien fire-tube combi boilers, NFC-H series (NFC-250/200H, NFC-250/175H) and NCB-H combi boilers (NCB-250/150H, NCB-240/130H, NCB-240/110H, NCB-190/080H, NCB-190/060H)

Common causes of Navien code E012

  • Clogged air intake filter
  • Poor ground on the power supply
  • Low or fluctuating inlet gas pressure

A technician checks these and 2 other possible causes on site before replacing any part.

Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Navien models that use code E012

NCB-190/060HNCB-190/080HNCB-240/110HNCB-240/130HNCB-250/150HNFC-250/175HNFC-250/200H

Other Navien Combi Boiler codes

CodeMeaning
E001Heat exchanger overheat
E003Ignition failure
E004False flame detected
E016Heat exchanger overheat (overheating of heat exchanger)
E030Exhaust overheat (abnormal exhaust temperature)
E031Burner overheat
E046Heat exchanger thermistor / overheat sensor fault
E047Exhaust thermistor fault
E060Dual venturi fault
E109Fan motor fault
E110Exhaust blockage / abnormal air pressure (APS)
E205Heating supply temperature sensor fault

All Navien Combi Boiler error codes →

Navien code E012: homeowner questions

What does Navien code E012 mean?

Flame loss. The flame went out during operation after ignition. NFC-H manual lists the reset type as: Manual reset.

Is it safe to keep using my combi boiler with code E012?

It depends on the cause. The combi boiler has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Can I reset Navien code E012 myself?

You can try one reset (power off for 30 seconds, then on). If Navien code E012 comes back, the cause is still there and a licensed technician should check it.

Who can fix Navien code E012 near me?

Aurora Star Tech Inc. repairs Navien combi boilers in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: Tankless Water Heater No Hot Water: What to Check · Boiler Not Heating: What to Check

Troubleshooting guides

Source: Navien NCB-H Installation & Operation Manual, 11.7 Understanding Error Codes, p.129-130; Navien NFC-H Installation Manual, 11.7 Understanding Error Codes, p.127-128. Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

Emergency HVAC Service

647-657-2977