b6
Over/under-voltage trip or over-temperature trip on blower motor
This code typically points to
- Line voltage outside motor operating range (too high or too low)
- Motor internal over-temperature condition
- Bearing or load condition causing overheating
Next checks to confirm
- Measure line voltage at furnace and compare to motor nameplate operating range
- Check blower motor amp draw and compare to nameplate
- Inspect blower wheel for obstruction or bearing issues
- Verify motor cooling path is not obstructed
Escalation
Blower motor trips; furnace fails to operate until voltage/temperature condition is corrected
Reset behavior
Clears after voltage/temperature condition returns to normal.
Urgent
Fix now