About your new thermostat
Wiring—Heat Pump
Alternate wiring (for heat pumps only)
If labels do not match letters on the thermostat, check
the chart below and connect to terminal as shown here
(see notes, below).
C
L
X
B
L
Leave metal jumper in place, connecting R & Rc
terminals.
If your old thermostat had both V and VR wires,
stop now and contact a qualified contractor for
help.
If your old thermostat had separate O and B
wires, wrap the B wire in electrical tape and do
not connect.
If your old thermostat had Y1, W1 and W2 wires,
stop now and contact a qualified contractor for
help.
If E and Aux terminals do not each have a wire
connected, use a small piece of wire to connect
5
them to each other.
Wiring complete, return to Step 8.
4
5
5
E
AUX
F
X
W
X2
W1
W2
E
Aux
RTH6350/RTH6450 Series
G
O
F
H
B
G
O/B
25
Y
R
Rc
Y1
V
R
M
VR
Y
R
Rc
2
MCR31275A
69-2416ES—05