Installation Guide
Connect wires (less common wire designations)
If labels do not match thermostat letters,
check the chart at right (see notes, below).
If the old thermostat had both V
and VR wires, contact a heating/
cooling contractor for help.
If the old thermostat had both O
and B wires, attach the B wire to
the C terminal. If another wire is
attached to the C terminal, call
1-800-468-1502 for help.
If the old thermostat had W1, W2
and Y wires, contact a heating/
cooling contractor for help.
If no wire matches the E terminal on the new thermostat,
use a small piece of wire to connect terminals E and Aux.
69-1891ES-1-RTH3100C-IG.CS5.indd 12
4
3
3
E
Aux
Y
G
or
or
or
or
X
W
Y1
F
X2
W1
M
W2
E
Aux Y
G
12
2
1
2
O
L
R
B
or
or
or
F
V
H
VR
O
L
R
B
5/17/2011 11:21:08 AM
2
C
or
B
X
C