Yellow LED continuous FLASH
Low flame sensor signal
This code typically points to
- Dirty flame rod
- Weak flame carryover
- Poor grounding
- Flame-sensor wire issue
Next checks to confirm
- Clean flame sensor and verify continuity
- Verify burner carryover and flame pattern
- Verify board/chassis grounding
Escalation
Repeated low flame signal after cleaning and grounding checks points to combustion quality issue.
Reset behavior
Status indicator during operation; does not itself cause lockout.
Service Soon
Schedule repair