Settings And Adjustments; Setting Fan And System Switches; Fan Switch; System Switch - Honeywell ELECTRONIC THERMOSTATS T8401C Installation Instructions Manual

SETTINGS AND ADJUSTMENTS

Setting FAN and SYSTEM Switches

Fan and system settings are controlled manually by
using the switches located at the bottom of the
thermostat case. See Fig. 11.
TEMPERATURE DISPLAY
S e t
R o o m

FAN SWITCH

Fig. 11. Digital Display and System Switches.
FAN Switch
Fan switch settings are:
On: The fan runs continuously. Use for improved air
circulation and air quality.
Auto: Normal setting for most homes. In cooling, the
fan starts and stops with the cooling equipment. In
heating, the fan is controlled directly by the heating
equipment and may start a few minutes after the
heating equipment turns on (on most systems). In
electric heat applications, the zone panel can be
configured to turn the fan on when the thermostat
calls for heat.
Slide the FAN switch in the bottom left corner of the
thermostat to select the desired fan setting.

SYSTEM Switch

System switch settings control thermostat operation as
follows:
Cool: The thermostat controls the cooling system. The
O terminal is energized.
Off: Both heating and cooling are off. O and B termi-
nals are de-engergized.
Heat: The thermostat controls the heating system.
The B terminal is energized.
Slide the SYSTEM switch in the bottom right corner of
the thermostat to select the desired system setting.
INCREASE SETTING
DECREASE SETTING
SYSTEM SWITCH
Set Temperature Setpoint
NOTE: NOTE: Temperature setpoint range is 40° to
99°F (5° to 37°C).
The temperature setpoint and the room temperature are
shown separately on the digital display. The
points to Set when the temperature setpoint is displayed
and to Room when the room temperature is displayed.
Set
To set temperature setpoint:
1. Select Heat or Cool by sliding the SYSTEM switch
in the lower right corner of the thermostat to the
desired mode. See Fig. 11.
2. To display the temperature setpoint on the digital
display, press either the
temperature setpoint is displayed for approximately
five seconds as the indicator points to Set and
flashes.
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3. To decrease the temperature setpoint press the
key. Each press changes the setpoint one degree;
press and hold to change the setpoint several
degrees.
4. To increase the temperature setpoint press the
key. Each press changes the setpoint one degree;
press and hold to change the setpoint several
degrees.
° °
Setting F/ C Indication and Heat Cycle Rate
NOTE: NOTE: To save changes to the °F/°C indication
and the heat cycle rate, all seven steps must be
completed.
To set the °F/°C indication and heat cycle rate:
1. If the temperature is displayed in °F, set the tem-
perature setpoint to 52°F. If the room temperature
is displayed in °C, set the temperature setpoint to
11°C.
5
T8401C ELECTRONIC THERMOSTATS
INDICATOR
ROOM TEMPERATURE
Room
SETPOINT TEMPERATURE
or key once. The
M14680
M14681
M14682
M14683
indicator
M14679
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