24
iThermostat
™
Installation Manual
Terminal Functions
The following chart shows the function for each terminal on your iThermostat.
Terminal
Typical Wire Color
Function/Description
C
Brown, Black or Blue
24 Volt Neutral (Common)
L
Varies
Malfunction Indicator
G
Green or Gray
Energizes Indoor Fan
Y2
Blue
Second Stage Cooling
W2
Black
Energizes Second Stage Heat
E/W1
White
Energizes First Stage Heat
Y1
Yellow
First Stage Cooling
R
Red
24 Volt Hot
B
Brown
Heat Pump Reversing Valve – Energized in Heating
O
Orange
Heat Pump Reversing Valve – Energized in Cooling
Installation Tip: Wire colors are typical and may not match your existing thermostat. Be sure to use wire
labels and do not go by wire color alone.