Green OFF / Red OFF
Control fault or no power
This code typically points to
- No 120V power to furnace
- No 24V control power / transformer issue
- Blower door switch open
- Blown 24V fuse
- Failed control board
Next checks to confirm
- Verify line voltage at furnace power input
- Verify door switch engagement and 24V availability
- Check transformer secondary voltage
- Inspect 24V fuse
Escalation
If proper power and fuse test good and both LEDs remain off, board failure is likely.
Reset behavior
No reset until power/fault is restored.
Service Soon
Schedule repair