What It Means
- Defrost while gas heat selected

Zone controller
System detected defrost signal at W1-Def terminal block while the jumper is selected for the furnace. May be caused by: • Wrong selection for indoor unit jumper. • Outdoor unit terminal block misfired. • Zone control system failure. Check unit installation instructions for correct wiring. If no signal is present at W1, then replace zone control panel.
Defrost while gas heat selected
HARMONY III, X9953
Continue in ACLogics with guided diagnosis for your equipment and symptoms.