6
Review the wiring chart information.
Refer to:
a.
Chart 1 - Gas furnace or air handler with electric heat
Chart 2 - Heat pump
Select the correct row based upon the thermostat being replaced, and then circle the wire labels you have.
b.
Connect your wires as shown in the New Thermostat Terminals row after completing steps 7 through 11. (Wiring
c.
diagrams have been provided for reference on pages 7 through 9.)
Thermostat Being Replaced
Wire Labels
All Brands
C
X
B
R
RC
RH
W
W1
W2
G
F
Y
Y1
Y2
Connects to
New Thermostat Terminals
24C
24RC
24RH
W1
W2/O/B
G
Y1
Y2
Chart 1: Gas furnace or air handler
with electric heat
(Single Stage or Multistage)
Thermostat Being Replaced
Wire Labels
Trane/American Standard (Weathertron)
or York
COM
C
B
R
RC
RH
E
X2
W
W1
W2
Y
AUX
O
G
Y
Y1
Y2
Other Brands
COM
C
X
R
RC
RH
E
X2
W
W1
W2
Y
AUX
O
B
G
F
Y
Y1
Y2
Lennox
C
X
R
RC
**VR
**V
RH
E
X2
W
W1
W2
Y
AUX
O
**R
G
F
Y
Y1
Y2
Connects to
New Thermostat Terminals
24C
24RC
24RH
*W1
W2/O/B
G
Y1
Y2
* Connect two wires to the W1 terminal
**If your existing thermostat has a “V” or “VR” wire label, connect that wire to “24RC” on the new thermostat,
then connect the wire labeled “R” to “W2/O/B” on the new thermostat
Chart 2: Heat Pump
(Single Stage or Multistage)
Some wire terminals may not be used
Some wire terminals may not be used
7
Remove existing wall plate.
Note: During this process, make sure that the wires do
not pull back into wall opening.
Detach all wires from wall plate.
a.
Remove all screws attaching the wall plate to the
b.
wall and remove wall plate.
See “MERCURY NOTICE” on page 1.
c.
Wall plate
4
