When the batteries are low, the display will flash REPL
BAT. REPL BAT indication will disappear when thermo-
stat is mounted back on the powered subbase with fresh
batteries. This may take up to 15 minutes to occur.
If batteries are completely dead, the display will go
blank when the thermostat is removed from subbase.
MOUNTING THE THERMOSTAT
With system switch set to OFF, hang the thermostat on
the tabs at the top of the subbase. See Fig. 10A. Swing
down and press on lower edge until thermostat snaps into
place. See Fig. 10B. Open cover and tighten the captive
mounting screws. See Fig. 10C.
SETTING DAY AND TIME
NOTE: Thermostat must be mounted on powered subbase
to program.
Restore 24V power to the thermostat. When power is
applied to the thermostat, the display will read 1:00 PM and
32° for a minute or less, followed by 1:00 PM and room
temperature. It will go off for a few seconds, then begin to
flash on and off. Set present day and time.
Press .
Press to set the current day. Each press of
the DAY key advances the display one day.
Press TIME or to set the current time.
If the display will not come on:
—check mounting of thermostat to subbase. If loose
or misaligned, remove thermostat and reinstall on
the subbase, making sure it is firmly attached.
—check to see that system power is on.
—check to see that voltage between R and C is 20 to
30 Vac.
Fig. 10—Mounting the thermostat on subbase.
M3059
PM
RETURN
MON HEAT ON
SYSTEM
AUTO
PM
RETURN
MON HEAT ON
SYSTEM
RUN
PROGRAM
TIME
TEMPERATURE
PRESENT
SETTING
SKIP
NEXT
PERIOD
CHANGE
TO LAST
PERIOD
SET
PRESENT
DAY/TIME
HOLD
TEMP
DAY
SET
HEAT/COOLSLEEP
LEAVEAHEADWARMER
RETURNBACKCOOLER
WAKE

A. B.

C.

HEATAUTOCOOLOFF
ONAUTO
FAN
EM. HT.AUX. HEAT
BACK
AHEAD
SET
PRESENT
DAY/TIME
DAY
5 69-0689—2
Checkout
CAUTION
During cold weather, some heat pumps will re-
quire that crankcase heater be energized several
hours before operating heat pump. Refer to
manufacturer’s recommendations.
HEATING
Move the system switch to HEAT and the fan switch to
AUTO. Press WARMER key until the setting is about
10° F [6° C] above room temperature. Heating should start
and the fan should run (there may be a delay of 5-10
minutes before heat turns on). Press COOLER key until the
setting is about 10° F [6° C] below room temperature. The
heating equipment and fan should shut off. The fan will run
a short time after equipment shuts off with T8631A unless
fan operation switch set for electric.
COOLING
CAUTION
Do not operate cooling if outdoor temperature is
below 50° F [10° C]. Refer to manufacturer’s
recommendations.
NOTE: When cooling setting is changed, thermostat can
wait up to five minutes before turning on the cooling
equipment. This delay is to protect the compressor.
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