Honeywell MAGICSTAT 3355 - Manual (Page 6)

6 69-1012
Step 2: Remove Old Thermostat
■ ■ Test to make certain that your heating and
cooling systems are working properly. If
either does not work, contact your local
heating/air conditioning dealer. To avoid
compressor damage, do not operate the
cooling system when outdoor temperature is
below 50
°
F (10
°
C).
■ ■ TURN OFF POWER to system at the
furnace, or at the fuse/circuit breaker panel.
■ ■ Carefully unpack your new thermostat and
mounting plate; save package of screws,
instructions and receipt.
■ ■ Remove the cover from the old thermostat.
If it does not snap off when pulled firmly
from the bottom, check for a screw used to
lock on the cover.
■ ■ Loosen screws holding thermostat to
subbase, wallplate or wall, and lift away.
■ ■ Disconnect wires from the old thermostat or
subbase. As you disconnect each wire, use
masking tape to label it with the old terminal
designation. If there are only two wires, they
do not need to be labeled. If there is an extra
wire that is not connected to your old
thermostat, you will
also not be connecting it
to your new thermostat. Wrap wires as shown
to keep them from falling back into the wall.
WIRES THROUGH
WALL OPENING
M5136