User's Manual

Step 6 Connect Wires
1) Match your previous wire configuration to
the new base. One by one, connect each
wire by inserting the metal end into the
corresponding slot and tightening the screw.
For a 5-wire system, use the guide below to help determine
how wires may convert from your current system to your new
THERM-500.
5
WIRE
* O/B is used in heat pump systems.
TIP: Use pliers to straighten wire before inserting into new base. Be sure
to cut any excess wire where the insulation extends to the terminal block.
when the wire is installed properly to the terminal block, there should be
no copper exposed.
Old Thermostat
Connector Function
New Thermostat
Connector
G or F Fan G
Y1 or Y Cooling / Compressor Y1
W1 or W Heating W1/O/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
8