Honeywell 20 troubleshooting answers
1 question with answers cited from the manufacturer manuals.
- 0Honeywell RM7800 Fault 20: Low Fire Switch Off, what to check?
Fault 20 on a Honeywell RM7800 series relay module indicates that the low fire switch did not close in time after the prepurge cycle, preventing the burner from lighting at a safe, low input. This fault occurs while the …