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7 69-0642—1
NOTE: To avoid compressor damage, do not operate the
system when outdoor temperature is below 50° F [10° C].
Refer to manufacturer recommendations.
Move both temperature setting levers together at least 5° F
[3° C] above the room temperature. The cooling equipment
should shut off.
Place the fan switch to ON. The fan should run continu-
ously with the system switch in any position.
Place the system switch to OFF. Move both temperature
setting levers to various positions. The heating and cooling
systems should not operate.
Operate the entire system for at least one complete cycle
with the system switch at COOL and one complete cycle
with the switch at HEAT.
If thermostat fails any test, refer to the Troubleshooting
Guide in the Owner’s Manual.
Reset both temperature setting levers to the desired tem-
peratures.
Leave Owner’s Manual and Assistance Information in a
convenient place for the building occupant or provide with
other appliance manuals.
Calibration
THERMOMETER
The thermometer in your thermostat was accurately cali-
brated at the factory. The thermometer should need adjust-
ment only if it has been dropped or shifted due to mishandling.
If the setpoint lever and the thermometer reading do not
agree:
1. Remove the thermostat cover by pulling up from the
bottom of cover until it clears the mounting slots.
2. Set the thermostat cover on a table near an accurate
thermometer.
3. Allow five minutes for cover thermometer to sense
area temperature; compare the readings. Be careful not to
touch thermometer or breathe on it.
4. If the readings are the same, replace cover and put the
system into operation.
5. If the readings are different, insert a small screwdriver
in the thermometer and turn it until the thermometers have
the same reading (Fig. 13).
6. Replace thermostat cover and put the system into
operation.
NOTE: Radiant heat from your hands will offset the ther-
mometer reading. After making each adjustment, wait five
or ten minutes for the thermometer to stabilize before
comparing.
THERMOSTAT
This thermostat was calibrated at the factory and should
not need recalibration in the field. If recalibration seems
necessary, first be sure wallplate or subbase is accurately
leveled. Then check thermometer calibration.
To check thermostat calibration, allow several hours of
operation after installation. Then read thermometer and
remove cover. Push temperature levers together to a setting
below room temperature. Slowly move them up the scale
together until the mercury slides across the tube. If the
thermometer reading and the high temperature lever posi-
tion are approximately the same at the instant the mercury
moves to the other end, no recalibration is needed.
Fig. 13—Thermometer calibration.
M5128
INCREASE
If calibration is necessary, proceed as follows:
1. Remove the cover.
2. Place open-end calibration wrench, part no. 104994A
(ordered separately), on the hex nut under the bimetallic coil
controlled by the red lever (Fig. 14). Hold lever so it does not
move, and gently turn the wrench clockwise until the
mercury rests securely in the right end of the tube.
3. Put the thermostat cover on and wait ten minutes.
4. Read the thermometer. Then remove the cover. Mov-
ing both levers, place the HIGH lever at the thermometer
reading. Hold lever so it does not move, and gently turn the
wrench counterclockwise until the mercury just slides
to the left end of the tube but no farther. Try to do this quickly
so the heat from your hands does not affect the thermostat.
5. Repeat this procedure for the blue lever.
Fig. 14—Use of 104994A calibration wrench.
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M8583
ANTICIPATOR
SETTING
LEVER
ANTICIPATOR
SCALEPLATE
CALIBRATION
WRENCH