Honeywell T874G User Manual

69-0268—11

12

T874G,R MULTISTAGE HEAT PUMP THERMOSTATS AND Q674F,J,L SUBBASES

Home and Building Control
Honeywell Limited-Honeywell Limitée
35 Dynamic Drive
Scarborough, Ontario M1V 4Z9

69-0268—11   J.S.   Rev. 12-95

If the setpoint lever setting and the thermometer reading
do not agree, follow the procedure below.

쐃

Remove thermostat cover by pulling the bottom
edge of the cover outward and away from the base
until it clears the retaining posts.

쐇

Set the cover on a table near an accurate
thermometer.

쐋

After allowing five or ten minutes for stabilization,
compare the readings. If they are the same, replace
cover and put system into operation. If they are
different, recalibrate the thermostat thermometer;
see step 4.

쐏

Insert a small screwdriver in the thermometer shaft
(Fig. 16) and turn it until the thermometers read the
same. When the thermometer is calibrated, replace
cover and place into operation.

NOTE:

Radiant heat from your hands will offset the
thermometer reading. After making each
adjustment, wait five or ten minutes for the
thermometer to stabilize before comparing.

THERMISTOR RESISTANCE (ohms)

C815A THERMISTOR RESISTANCE
R = 400 ohms ± 10% AT 77°F (25°C)

4600
4400
4200
4000
3800
3600
3400
3200
3000
2800
2600
2400
2200
2000
1800
1600
1400
1200
1000

800
600
400
200

0

-20         0         20        40        60        80        100      120       140

TEMPERATURE OF THERMISTOR (°F)

M1590A

M5070

Home and Building Control
Honeywell Inc.
1985 Douglas Drive North
Golden Valley, MN 55422

www.honeywell.com/yourhome