Navien boiler error E012

What causes E012

The flame went out during operation.

What to do

Reset the boiler. If it continues, the flame rod and gas pressure need checking.

Can I fix it myself?

No. This is a fault a technician should handle; keep using the appliance and it can get worse or become unsafe.

If the code comes back

Book a visit and add the code to the booking. A technician arrives knowing which parts to bring, diagnoses the boiler for a flat $89 and gives you an exact quote before doing any work.