Install Instructions

Terminal Designations
Wiring Notes
Common wire
The C (common wire) is optional when the thermostat is
powered by batteries.
Wire Specications
Use 18- to 22-gauge thermostat wire. Shielded wire is not required.
Notes:
In many heat pump systems without emergency heat relay, a jumper can be
installed between E and W2 to the turn thermostat into a single stage control
for Emergency Heat Operation.
Installation Tip: Do not overtighten terminal block screws, as this
can damage the terminal block. A damaged terminal block can
keep the thermostat from tting on the subbase correctly or cause
system operation issues. Max Torque = 6in/lbs.
Power supply
Factory-installed jumper. Remove only when installing on
2-transformer systems.
Use either O or B terminals for reversing valve.
Optional 24 VAC commom connection when thermostat is used in
battery power mode.
Wiring Wiring Diagrams
Wiring Diagrams
Wiring Diagrams
5 6
7 8
This thermostat is shipped from the factory to operate a conventional heating
and cooling system. This thermostat may also be congured for a heat pump
system. See the “heat pump” conguration step on page 14 of this manual to
congure the thermostat for heat pump applications.
Terminal
2 Heat 2 Cool
Conventional System
2 Heat 1 Cool
Heat Pump System
3 Heat 2 Cool
Heat Pump System
RC
24 VAC power (Cooling) 24 VAC power (Cooling) 24 VAC power (Cooling)
RH
24 VAC power (Heating) 24 VAC power (Heating) 24 VAC power (Heating)
C
24 VAC common 24 VAC common 24 VAC common
B
Reversing valve / congurable terminal Reversing valve / congurable terminal Reversing valve / congurable terminal
O
Reversing valve / congurable terminal Reversing valve / congurable terminal Reversing valve / congurable terminal
G
Fan relay Fan relay Fan relay
W/E
First stage ofheat Emergency Heat First stage of auxiliary heat
Y
First stage ofcool First stage of heat & cool First stage of heat & cool
Y2
Second stage ofcool N/A Second stage ofheat & cool
W2
Second stage ofheat Auxiliary heat Second stage of auxiliary heat
Typical 2H/2C System: 1 Transformer
HEAT RELAY
HEAT RELAY 2
COMPRESSOR
RELAY
COMPRESSOR
RELAY 2
FAN RELAY
HOT
Typical Cool-Only System With Fan
FAN RELAY
COMPRESSOR
RELAY
HOT
REMOVE JUMPER
HEAT RELAY
HEAT RELAY 2
FAN RELAY
COMPRESSOR
RELAY
COMPRESSOR
RELAY 2
Typical 3H/2C or 2H/1C Heat Pump System
COMPRESSOR
RELAY
COMPRESSOR
RELAY 2
AUXILIARY
HEAT RELAY
EMERGENCY
HEAT RELAY
COOL REVERSING
VALVE
HEAT REVERSING
VALVE
FAN RELAY
HOT
HOT
Typical 2H/2C System: 2 Transformers
Typical Heat Only System With Fan
HEAT RELAY
FAN RELAY
HOT
Note:
In many systems with no emergency heat relay a jumper can be installed between
E and W2