W2....................Auxiliary heat relay
Y .......................Compressor relay
G ......................Fan relay
O ...................... Heat pump reversing valve energized in cooling
R ......................24VAC Power
C ......................Common wire from system transformer
B ...................... Heat pump reversing valve energized in heating
W/E ..................Emergency heat relay
Note:
In many heat pump systems without an emergency heat relay, a jumper can be
installed between E and W2 to turn the thermostat into a single stage control for
Emergency Heat Operation.
TERMINAL DESIGNATIONS
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