Honeywell CT3400 Thermostat User Manual


 
5 69-0733—3
which programmable thermostats will work with
your system, call Honeywell Customer Assis-
tance at 1-800-468-1502.
Three thermostat wires?
If you have three wires for heating only and can
operate the fan using the fan ON switch, this
thermostat will work with your system. However,
some hot water (zoned) heating systems have
three thermostat wires. The thermostat will not
work without installing an isolating relay on these
systems. For details, call Honeywell Customer
Assistance at 1-800-468-1502.
not allow them to touch, or you can damage your
transformer. Disconnect the wires and wrap
them separately using electrical tape;
do not
wrap them together
. Place the wires where they
will not interfere with the operation of the new
thermostat. Record the colors and terminal des-
ignation labels of the remaining wires.
Six or more wires?
If there are six or more wires (excluding clock
wires attached to terminals), you most likely
have a variation of a heat pump or multistage
system. The thermostat is
not
compatible with
such systems so return the product to the place
of purchase. If you would like information about
6 69-0733—3
STEP 3 Before You Program
M2589
INSTALL 3 AA ALKALINE BATTERIES AS SHOWN, 
POSITIVE (+) TERMINALS TOWARD RIGHT.
BACK OF THERMOSTAT
Install the Batteries
IMPORTANT:
Three AA alkaline batteries are
included with the thermostat. Batteries must
be installed for programming and operation of
the thermostat and heating/cooling system.
Install the batteries in back of the thermostat
as shown, making sure positive (+) terminals all
face toward the right.
As the batteries are running low, a REPL BAT
indicator will flash for 1 to 2 months before bat-
teries run out completely. Replace the batteries
as soon as possible after the indicator starts
flashing.
If you insert new batteries within 20 to 30 sec-
onds of removing the old ones, you will not have
to reprogram the thermostat. However, if the
display is blank, the batteries are dead or
incorrectly installed. In this case, you will
have to reprogram. See pages 13 through 15
to reprogram. If you do not reprogram, the
factory-prepro-
grammed
settings will be
in effect, as
shown in
chart on
pages 11
and 12.