York LX series Owner's Manual page 17

Installation Instructions
The LX Thermostat Backplate
R
C
G AUX
OUTDOOR
W1/O/B
SENSOR
W2
Y1
REMOTE
Y2
SENSOR
W3
DRY
HUM
CONTACT
FAULT
DEHUM
R 24 VAC return
G Fan relay
W1/O/B
1st stage heat circuit
W2 2nd stage heat circuit
Y1 1st stage compressor relay
Y2 2nd stage compressor relay
W3 3rd stage heat circuit
HUM Humidifier control circuit
DEHUM Dehumidifier control circuit
IMPORTANT:
This thermostat requires both
R (24 VAC Return) and C (24 VAC Common) be
connected to the backplate terminals.
To remove the thermostat
backplate: Using the Finger
Pull Areas, pull the front
housing away from the
backplate.
Front Housing
Finger Pull Areas
C 24 VAC common
AUX Aux output
OUTDOOR Outdoor sensor
connections
SENSOR
REMOTE Remote sensor
connections
SENSOR
DRY Dry contact
connections
CONTACT
FAULT Fault input
Page 9
Backplate