Follow Special Instructions - Honeywell RTH8500D 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
G
C
C
Y
R
DO NOT CONNECT TO NEW
THERMOSTAT
LETTER
W
DESIGNATION
SCREW
TERMINAL
WIRE
WIRE HOLE
7
M22201
69-1725-1