Page 4
Overview
Heat Pump HVAC System Wiring
Terminal Marking
Meaning
Typical Wire Color
Record the old thermostat wire
connections and
terminal marking here
C
24VAC Common
Blue
R
24VAC Return
Red
G
Fan
Green
W or W1
Aux Heat
White
Y or Y1
Compressor stage 1
Yellow
O (or B*)
Change Over Valve
Orange (brown*)
Y2
Compressor stage 2
Black
If you have a terminal marked “B” with a brown wire attached to it, that means you have a changeover (C/O) with heating
type heat pump system. Be sure to set the change over type in the
Installer Settings
menu to
C/O Type: w/ Heat
.
Otherwise, leave it set to
w/ Cool
.
Standard HVAC System Wiring
Terminal Marking
Meaning
Typical Wire Color
Record the old thermostat wire
connections and
terminal marking here
C
24VAC Common
Blue
R
24VAC Return
Red
G
Fan
Green
W or W1
Heat stage 1
White
Y or Y1
Cool stage 1
Yellow
W2
Heat stage 2
Orange
Y2
Cool stage 2
Black
