Single-stage HP · Y + O/B
24V Y / C / O or B
GSZ14 class. Contactor + dual cap + defrost board + reversing valve. O/B direction is board-specific — do not assume Carrier O-on-cool.
Written circuit description only — FieldBench does not redraw maker schematics. Example: R to W closes on a heat call; verify 24V at W1 before you change the IFC.
Open manufacturer PDF24V heat pump
Single-stage HP outdoor with a defrost board.
Heat-pump thermostat
Y, O/B, C, W/E aux. Confirm O vs B on THIS board.
- R24V hot24V
- CCommon24V
- YCompressor24V
- O/BReversing valve24V
- GIndoor fan24V
- W/EAux / emergency24V
Defrost board + contactor
Y to the board / coil. O/B to the RV solenoid per the diagram on the door.
- YCompressor request24V
- CCommon24V
- O/BRV — read the silk24V
Outdoor line
208/230 through the disconnect to the contactor line side.
- L1LineLine
- L2LineLine
- GNDEquipment groundLine
Dual run capacitor
C / FAN / HERM on the can. An inverter outdoor does not have this part.
- CCommon — both windingsCap
- FANOutdoor fanCap
- HERMCompressorCap
Landing
- 24VStat Yindooroutdoor Y
~24 VAC compressor
- 24VStat O/Boutdoor RV
Energize direction is THIS board, not a Carrier habit.
Prove it
- Y–C at the outdoor under a compressor call.
- O/B voltage vs the door: energized in cool or heat on THIS silk.
Do not
- Do not use the GSX16 AC diagram. There is an RV and a defrost board here.
- Do not assume O-on-cool.
O/B polarity is the #1 callback. Read the outdoor diagram.