HEAT PUMP THERMOSTAT
SETTINGS
CHECKOUT
Temperature Setting
Heating
The enlarged, raised numbers on the right edge of the
thermostat can be used for easy temperature setting by
touch or sight while moving the temperature setpoint
lever to the desired temperature setting. The large 5, 6, 7
and 8 refer to 50°F (10°C), 60°F (16°C), 70°F (21°C) and
Move the System switch on the thermostat to HEAT and
the Fan switch to AUTO. Move the temperature setpoint
lever to about 10°F (6°C) above the room temperature.
Heating should start and the fan should run. Move the
setpoint lever about 10°F (6°C) below the room
8
0°F (27°C), respectively. A click is heard with indents
temperature. Heating and fan should shut off.
every two degrees as the temperature setpoint lever is
moved. See Fig. 1.
IMPORTANT
To prevent compressor short cycling, a mini-
mum-off timer can be included to prevent the
compressor from starting for up to five minutes
from when the thermostat last turned off the
compressor, or from when the system first
received power.
System Switch Setting
The enlarged, raised letters on the left bottom edge of the
wallplate can be used for easy recognition of System
switch settings:
For the T841A Thermostat: The large EH, H, O and C
refer to EM. HT., HEAT, OFF and COOL.
For the T841B Thermostat: The large H, O and C refer
to EM. HT., HEAT, OFF and COOL.
Cooling
The System switch settings control the system operation
as follows:
CAUTION
Compressor Damage Hazard.
Operating cooling equipment in cold weather
can damage compressor.
EM.HT (only on T841A): Emergency heat relay is
energized. Cooling system is off. Compressor is
de-energized. Fan runs on call for heat if the Fan
switch is in the AUTO position. EM. HT. LED is on.
HEAT: Heating system is automatically controlled by
the thermostat. Cooling system is off.
Do not operate air conditioner if outdoor
temperature is below 50°F (10°C).
Move the System switch on the thermostat to COOL and
the Fan switch to AUTO. Move the temperature setpoint
lever about 10°F (6°C) below the room temperature.
Cooling and fan should start (see Note in Checkout
section). Move the setpoint lever about 10°F (6°C) above
the room temperature. Cooling and fan should shut off.
OFF: Both the heating and cooling systems are off. If
the fan is set to the AUTO position, the cooling fan
is also off.
COOL: Cooling system is automatically controlled by
the thermostat. Heating system is off.
Fan Switch Setting
Fan
On theT841A,B, large A, O raised letters on the right
bottom edge of the wallplate refer to AUTO and ON fan
settings. The Fan switch settings control the fan as
follows:
Move System switch to OFF, and Fan switch to ON. The
fan should run continuously. Move Fan switch to AUTO.
In this position, the fan operates in response to the
thermostat in both heating and cooling.
AUTO: Fan operates in response to thermostat in both
heating and cooling.
ON: Fan operates continuously.
Automation and Control Solutions
Honeywell International Inc.
Honeywell Limited-Honeywell Limitée
35 Dynamic Drive
Scarborough, Ontario
M1V 4Z9
1
985 Douglas Drive North
Golden Valley, MN 55422
Printed in U.S.A. on recycled
paper containing at least 10%
post-consumer paper fibers.
69-1043-2 G.H. Rev. 3-03
www.honeywell.com/yourhome