Install Instructions

1 HEAT / 1 COOL - No Auxiliary Heat
R 24 VAC Power
O/B Changeover Valve [Note 2]
Y1 Compressor Call (1st Stage Heating/Cooling)
G Fan Call
C 24 VAC Transformer Common [Note 1]
2 HEAT / 2 COOL - No Auxiliary Heat
R 24 VAC Power
O/B Changeover Valve [Note 2]
L Optional System Fault Monitor
Y1 Compressor Call Stage 1 (1st Stage Heating/Cooling)
Y2 Compressor Call Stage 2 (2nd Stage Heating/Cooling)
G Fan Call
C 24 VAC Transformer Common [Note 1]
HEAT PUMP THERMOSTATS (for use on heat pump systems only)
2 HEAT / 1 COOL - With Auxiliary Heat
R 24 VAC Power
O/B Changeover Valve [Note 2]
L Optional System Fault Monitor
AUX Auxiliary Heat Relay (2nd Stage Heating)
Y1 Compressor Call (1st Stage Heating/Cooling)
E Emergency Heat Call
G Fan Call
C 24 VAC Transformer Common [Note 1]
3 HEAT / 2 COOL - With Auxiliary Heat
R 24 VAC Power
O/B Changeover Valve [Note 2]
L Optional System Fault Monitor
AUX Auxiliary Heat Relay (3rd Stage Heating)
Y1 Compressor Call (1st Stage Heating/Cooling)
Y2 Compressor Call (2nd Stage Heating/Cooling)
E Emergency Heat Call
G Fan Call
C 24 VAC Transformer Common [Note 1]
NOTES
[1] Wiring to the C terminal is required only for thermostat power.
[2] O (Cool active) or B (Heat active) must match the zone panel
configuration (section 4).
Thermostat Wiring
3.2
7