Goodman
No Y
ProtectOutdoor silent
No 24 VAC at the contactor or the coil is open.
Walk No Y in Diagnose
3 plates — walk the one on the cabinet
First check
1 Is Y actually at the contactor?
On Goodman GLXS4B a silent outdoor is often no Y. Measure 24 VAC coil-to-C at the contactor on a cool call. Y and C at the outdoor. Indoor IFC / stat actually closing Y.
Expect: ~24 VAC at the coil when the indoor is calling.
If fail: Indoor Y / IFC / stat — not a capacitor.
The rest of the walkthrough is Diagnose.
On the plates
- Y and C at the outdoor. Indoor IFC / stat actually closing Y.
- Contactor coil ohms. Do not confuse a furnace lockout with a dead outdoor.
- Y and C at the outdoor. Indoor actually calling.
- Defrost board output to the contactor.
Plates that use No Y
Same number, other makers
No Y on Goodman is not the same code on these plates.