2
Installer Guide
2
The
Thermostat Backplate
To remove the thermostat backplate:
Gently separate the display from the
base by pulling from the center.
R
C
AUX
DEHUM
HUM
W3
W2
W1/O/B
G
Y1
Y2
REMOTE/ OUTDOOR
DR
Y
CONT
ACT
To remove the thermostat
backplate from the wall: pry
with screwdriver in either
slot to remove back plate
R
24 VAC return
G
Fan relay
W1/O/B
1st stage heat circuit
or reversing valve
W2
2nd stage heat circuit*
W3
3rd stage heat circuit**
Y1
1st stage compressor
(Cool or Heat)
Y2
2nd stage compressor
(Cool or Heat)
C
24 VAC common
AUX
Ventilation Control
HUM
Humidifier control circuit
DEHUM
Dehumidifier control circuit
DRY
FDD alerts, twist timer, etc.
CONTACT
REMOTE
Remote sensor connections
SENSOR
OUTDOOR Outdoor sensor connections
SENSOR
IMPORTANT: This thermostat requires both R (24 VAC Return) and
C (24 VAC Common) be connected to the backplate terminals.
*3rd stage heat for heat pumps with two compressor stages
**4th stage heat for heat pumps with two compressor stages
PSP4273_Installer man.indd 2
PSP4273_Installer man.indd 2
6/9/21 11:23 AM
6/9/21 11:23 AM