Heat Pump/Thermostat Wiring and Operation
Heat Pump brand is NORMALLY HEAT/ A.K.A
Heat Pump with O/B energized in Cooling:
Call:
Dipswitch:
Heat
3 (ON), 4 (ON)
Wiring:
Wire Y from the stat to Y1 on the board. Wire Y1T from
the board to Y on the heat pump.
1.
Action:
Stat sends heat call signal from Y1 to Y1T on the board
and outputs the signal from Y1T on the board to Y on the
heat pump. This engages the heat cycle since the
reversing valve is in its relaxed/non-energized position.
**NOTE**
Reverse valve solenoid is: Energized in Cool Mode
De-Energized in Heat Mode
1
Heat Pump brand is NORMALLY HEAT/ A.K.A
Heat Pump with O/B energized in Cooling:
Call:
Dipswitch:
Cool
3 (ON), 4 (ON)
Wiring:
Wire W/OB from stat to W1/OB on the board. Wire
from W1T/OB from the board to O/B on the heat pump.
2.
Action:
Stat sends cool call signal from W/OB to W1/OB on the
board and outputs the signal to W1T/OB on the board to
O/B on the heat pump. This engages the cool cycle since
the reversing valve is in its energized position.
**NOTE**
Reverse valve solenoid is: Energized in Cool Mode
De-Energized in Heat Mode
2
Heat Pump brand is NORMALLY COOLING/ A.K.A
Heat Pump with O/B energized in Heating:
Call:
Dipswitch:
Heat
3 (ON), 4 (OFF)
Wiring:
Wire W/OB from the stat to W1/OB on the board. Wire
from W1T/OB on the board to O/B on the heat pump.
3.
Action:
**NOTE**
Stat sends heat call signal from W/OB to W1/OB on the
board and outputs the signal to W1T/OB on the board to
O/B on the heat pump. This engages the heat cycle since
the reversing valve in its energized position.
Reverse valve solenoid is: Energized in Heat Mode
De-Energized in Cool Mode
3
Heat Pump brand is NORMALLY COOLING/ A.K.A
Heat Pump with O/B energized in Heating:
Call:
Dipswitch:
Cooling
3 (ON), 4 (OFF)
Wiring:
Wire Y from the stat to Y1 on the board.
Wire Y1T from the board to the Y on the heat pump.
4.
Action:
Stat sends cool signal from Y to Y1 on the board and
outputs the signal to Y1T on the board to Y on the heat
pump. This engages the cool cycle since the reversing
valve is in its relaxed/non-energized position.
**NOTE**
Reverse valve solenoid is: Energized in Heat Mode
De-Energized in Cool Mode
4
Common Heat Pump Brands
Brand
Rev. Valve Energizes In
 Buderus
 Carrier
Diagram
Cooling
Cooling
1 or 2
1 or 2
Cooling
Cooling
1 or 2
1 or 2
Heating
Cooling
3 or 4
1 or 2
Heating
Cooling
Cooling
Heating
Cooling
Cooling
Cooling
3 or 4
1 or2
1 or 2
3 or 4
1 or 2
1 or 2
1 or 2
(Bryant,Payne, ICPArcoaire,Comfortmaker,Heil,Keeprite)
 Goodman(Amana,Janitrol)
 Lennox
(Armstrong,Ducane,Aires,Concord)
 Mitsubishi
 Nordyne
(Gibson,Broan,Maytag,Kelvinator,Frigidair,Tappan,Philco)







Rheem(Ruud)
Samsung
Sanyo
Sears(Kenmore)
Trane(Amer.Std,G.E)
Whirlpool
York(Coleman,Luxair,Dayton)
5