Green FLASH / Red FLASH
L1 / neutral polarity fault
This code typically points to
- Reversed hot/neutral at supply
- Grounding issue
- Supply wiring error
Next checks to confirm
- Check incoming hot/neutral polarity with meter
- Verify grounding and neutral integrity
- Inspect furnace bonding
Escalation
Recurring polarity indication after verified supply points to wiring or board input issue.
Reset behavior
Clears when polarity is corrected.
Service Soon
Schedule repair