Follow Special Instructions - Honeywell RTH7400D Owner's Manual

Step 4. Follow Special Instructions
1. If you have two C and/or C1 wires connected to
your old thermostat, do not connect them to your
new thermostat.
2. Disconnect the C and/or C1 wires. Make sure they
do not touch each other or any other wires.
3. Wrap the bare end of each C and/or C1 wire with
electrical tape.
OLD THERMOSTAT
Y
G
C
C
W
R
DO NOT CONNECT TO NEW
THERMOSTAT
7
LETTER
DESIGNATION
SCREW
TERMINAL
WIRE
WIRE HOLE
M22201
69-1726—1