Venstar T7900 - Manual (Page 79)

71
Installation Instructions
Wire Connections
If the terminal designations on your old thermostat do not match those
on the new thermostat,
refer to the chart below or the wiring
diagrams that follow.
Wire from the Install on the
old thermostat Function new thermostat
terminal marked connector marked
G or F Fan G
Y1, Y Cooling Y1
W1, W Heating W1/0/B
Rh, R, M, Vr, A Power R
C Common C
O/B Rev. Valve W1/O/B*
W2 2nd Stage Heat W2
Y2 2nd Stage Cooling Y2
W3 3rd Stage Heat W3
OUT - Outdoor Sensor SENSOR
OUT + Outdoor Sensor SENSOR
* O/B is used if your system is a Heat Pump.