STEP 8
Wire Thermostat Terminals
NOTE: All wiring must comply with local codes
and ordinances. If unsure about household
wiring procedures, call your local heating/air
conditioning contractor.
Refer to masking tape labels you placed on wires
when you removed your old thermostat.
■
■
Match the letter of your old thermostat wire
with the terminal of the corresponding letter on
the back of your new thermostat. Refer to
illustrations on pages 22 and 23. Hold the
thermostat as shown to minimize need for wire
extenders. If wires are still too short, use wire
20
M1715A
WIRE NUT SIZE
FOR TWO
18-GAUGE WIRES
WIRE
FROM
WALL
6-in. [152 mm] OF
18-GAUGE
THERMOSTAT
WIRE. MATCH
INSULATION
COLORS OR
MARK WIRE ENDS.
METHOD TO INCREASE WIRE LENGTH
connectors (purchased locally) to extend wires.
See illustration (above) for guidelines on using
wire extenders.
■
■
In 5-wire installations only, be sure to
remove the factory-installed jumper
connecting terminals R and Rc.
■
■
Loosen the terminal screws and slip each
wire beneath its matching terminal. See
illustration (lower right) for wire insertion
technique. Tighten terminals securely.
■
■
Plug the hole in the wall with insulation to
help prevent drafts from adversely affecting
thermostat operation.
INSTALLATION
21
M1712A
JUMPER (FACTORY-
INSTALLED) REMOVE
IF 5-WIRE SYSTEM
INSERT
STRAIGHT
UNDER
SCREW HEAD
5/16 in.
[8 mm]
STRIP
END OF WIRE
VISIBLE HERE
R
Rc
W
Y
G
PROPER WIRING TECHNIQUE
M3666
PROPER WIRING TECHNIQUE