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URGENT - System Lockout

Navien Error Code E012

Flame Loss During Operation

Emergency Service Available Now
E012 indicates your boiler has lost flame during operation and may have locked out. This requires professional diagnosis and repair. Same-day service available.

What Does E012 Mean?

Error code E012 indicates that the flame was detected during ignition but was then lost during the heating operation. The flame sensor detected the loss of flame and shut down the system as a safety precaution.

This is a safety lockout that prevents unsafe operation and potential gas buildup. The system will not restart until the underlying issue is resolved and the error is cleared.

Common Causes of E012

Gas Supply Issues
Interrupted or insufficient gas supply can cause flame loss during operation. This may be due to low gas pressure, gas valve issues, or supply interruptions.
Venting Problems
Blocked or restricted exhaust/intake venting can disrupt combustion airflow, causing the flame to extinguish. Check for blockages, ice buildup, or improper termination.
Flame Sensor Malfunction
A dirty, corroded, or faulty flame sensor may fail to detect the flame properly, causing a false flame loss detection.
Air/Gas Mixture Issues
Improper air-to-gas ratio can result in unstable combustion. This may require professional adjustment of the gas valve or air intake.
Heat Exchanger or Burner Issues
Carbon buildup on the burner or heat exchanger can disrupt the flame pattern and cause loss of flame.

Immediate Steps

Check Gas Supply

Verify that the gas shut-off valve is fully open and other gas appliances in your home are working properly.

Inspect Venting

Check the exhaust vent termination outside for blockages, ice, snow, or debris. Clear any visible obstructions.

Do NOT Attempt Multiple Resets

Do not repeatedly attempt to restart the boiler. Flame loss errors indicate a potentially dangerous condition that requires professional diagnosis.

Call a Professional

E012 requires professional diagnosis and repair. Contact a licensed HVAC technician immediately for safe resolution.

Why Professional Service is Essential

Safety First

Flame loss during operation can indicate gas supply, venting, or combustion issues that pose safety risks if not properly diagnosed and repaired.

Specialized Equipment Required

Properly diagnosing E012 requires gas pressure testing, combustion analysis, and potentially specialized sensor testing equipment.

Warranty Protection

DIY repairs may void your Navien warranty. Professional service ensures proper repairs while maintaining warranty coverage.

What Our Technicians Will Do

1

Test gas supply pressure and verify proper gas valve operation

2

Inspect and test the venting system for proper airflow and termination

3

Clean and test the flame sensor and associated wiring

4

Perform combustion analysis and adjust air/gas mixture if needed

5

Inspect the burner and heat exchanger for carbon buildup or damage

6

Test the system through multiple heating cycles to ensure stable operation

Prevention Tips

• Schedule annual professional maintenance to keep combustion components clean

• Keep exterior vent terminations clear of snow, ice, and debris year-round

• Monitor your gas supply and report any irregularities to your gas provider

• Address any unusual sounds or performance issues promptly

Get Expert Navien E012 Repair

Our Vancouver-based technicians specialize in Navien boiler diagnostics and repair. Same-day emergency service available.