E6
Flame sense microamp signal is low
This code typically points to
- Coated/oxidized flame sensor
- Flame sensor incorrectly positioned in burner flame
- Lazy burner flame due to improper gas pressure or combustion air
Next checks to confirm
- Clean flame sensor
- Inspect sensor alignment
- Inspect air inlet piping
- Compare gas pressure to rating plate and adjust as needed
Escalation
Furnace may continue to run with reduced flame-sense margin; can progress to ignition failure/lockout
Reset behavior
Clears when flame-sense signal returns to acceptable range.
Service Soon
Schedule repair