Settings And Adjustments; Setting Fan And System Switches; Fan Switch - Honeywell T8400C Product Data

T8400C, T8401C AND T8424C,D ELECTRONIC THERMOSTATS
Mounting Thermostat to Wallplate
1. Engage the tabs at the top of the thermostat and wallplate.
2. Swing down the thermostat and press the lower edge of
the thermostat onto the wallplate to latch. See Fig. 10.
DASHED LINES INDICATE TABS
ON BACK OF THERMOSTAT
Set Room
FAN SYSTEM
Auto On Cool Off Heat
A
ENGAGE TABS AT TOP
OF THERMOSTAT WITH
SLOTS ON WALLPLATE.
M11025B
Fig. 15. Mounting T8400 or T8401 thermostat to wallplate.
A
ENGAGE TABS AT TOP OF THERMOSTAT
WITH SLOTS ON MOUNTING PLATE.
B
PRESS LOWER EDGE OF
CASE TO LATCH.
Fig. 16. Mounting T8424 thermostat to wallplate.
68-0180-3
Set Room
FAN SYSTEM
Auto Cool Off Heat
B
PRESS LOWER EDGE OF
CASE TO LATCH.
DASHED LINES INDICATE TABS
ON BACK OF THERMOSTAT
M14677
8

SETTINGS AND ADJUSTMENTS

Setting Fan and System Switches

Fan and system settings are controlled manually using the
switches located at the bottom of the thermostat case. See
Fig. 17 or 18.
Set Room
FAN
Auto On

FAN SWITCH

Fig. 17. T8400 and T8401 temperature
display and system switches.
TEMPERATURE DISPLAY
FAN SWITCH
Fig. 18. T8424 temperature display and system switches.
Fan Switch
Fan switch settings are:
ON: The fan runs continuously. Use for
improved air circulation.
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
TEMPERATURE DISPLAY
INCREASE
SETTING
DECREASE
SETTING
SYSTEM
Cool Off Heat
SYSTEM SWITCH
M11020A
INCREASE SETTING
DECREASE SETTING
M14678
SYSTEM SWITCH