4+1
Watchguard — exceeded maximum number of retries
This code typically points to
- Repeated ignition failure
- Gas flow issue
- Flame sensing issue
Next checks to confirm
- Per ML180UH public sequence, five consecutive failed flame-proving tries during one heat demand lead to watchguard and 60-minute reset period
- Verify igniter, gas delivery, and flame current
Escalation
Watchguard; heating inhibited until reset period completes
Reset behavior
Auto clears after 60 minutes or after a successful subsequent heat call, depending on fault branch.
Urgent
Fix now