About your new thermostat, Wiring – Honeywell RTH 3100C User Manual
Page 18

Advanced Installation Guide
69-2340ES—01
16
About your new thermostat
SETUP
WIRING
ASSIST
ANCE
TROUBLESHOOTING
Wiring
If labels do not match letters on the thermostat, check
the chart below and connect to terminal as shown here
(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.
Aux
Y
G
O
L
R
B
C
E
Aux Y
G
O
L
R
B
C
E
4
3
3
2
1
2
2
OR
X
X2
OR
W
W1
W2
OR
Y1
M
OR
F
OR
F
OR
V
VR
OR
H
OR
B
X
MCR29577