3 Installer Guide
Provide Power
C
24VAC Power Terminal (C)
2
Connect Your Wires
3
+
+
•
For 24 Volt AC power, you must connect the common side of the transformer to the C terminal on the thermostat
sub-base. In dual transformer installations, the transformer common must come from the cooling transformer.
• For battery power, insert the 2 supplied “AA” type alkaline batteries into the battery compartment located in the rear
housing of the thermostat. Make sure to position the Positive (+) and Negative (-) sides of the batteries correctly with
the +/- symbols in the battery compartment.
• If connecting this thermostat to a Wi-Fi network, a 24 VAC common (C wire) is required.
Batteries Installed as Shown
Terminal
Function
Description
Rc
Input
24 Volt AC Cooling Transformer
(Dual Transformer Systems Only)
Rh
Input
Power Connection (24 Volt AC
Heating Transformer)
C
Input
24 Volt AC Transformer Common
W2 / AUX
Output
(W2) 2nd Stage Conventional Heat
(AUX) Auxiliary Heat (Heat Pump)
W1 / E
Output
(W1) 1st Stage Conventional Heat
(E) Emergency Heat
L
Input
System Malfunction Indicator
A
Output
Economizer, Fresh Air or Output Control
O / B
Output
(O) Cool Active Reversing Valve
(B) Heat Active Reversing Valve
G
Output
Fan Control
Y2
Output
2nd Stage Compressor
Y1
Output
1st Stage Compressor
K
-
Optional Share-a-Wire
TM
module connection
S2
S1
Input
Optional Wired Remote Sensor
(indoor or outdoor)