Honeywell THX9421 Thermostat User Manual


 
THX9321 PRESTIGE
®
2.0 AND THX9421 PRESTIGE
®
IAQ 2.0 WITH EIM
69 68-0311—01
7. Set the desired lockout option. See Fig. 124.
Fig. 124.
NOTE: ISU 10140 gives the option to lockout ventila-
tion during calls for dehumidification. This helps
maintain the desired humidity level.
Dehumidification Away Mode
Dehumidification Away Mode protects the home when
unoccupied for long periods of time during hot and humid
weather by maintaining the desired humidity and temperature
settings.
To start Dehumidification Away Mode, press MENU, then press
Dehumidification Away Mode.
Fig. 125.
The thermostat automatically follows settings that are set by
the dealer during installer setup.
Press Cancel to end Dehumidification Away Mode.
Fig. 126.
Set up Dehumidification Away Mode
1. Select Allowed at ISU 9180. See Fig. 127.
Fig. 127.
2. Set Fan Control settings. See Fig. 128.
On: Fan is always on.
Automatic: Fan runs only when cooling system is on.
Circulate: Fan runs randomly, about 35% of the time.
Fig. 128.
3. Set temperature and dehumidification settings. See Fig.
130.
Low Limit Temperature Setting
If the cooling system is used to control humidity while
Dehumidification Away Mode is active, the thermostat
allows the cooling system to lower the indoor air to the
Low Limit Temperature Setting to reach the
Dehumidification Setting at ISU 9200.
Temperature Setting
The temperature maintained while Dehumidification
Away Mode is active and the desired humidity level is
satisfied.
Dehumidification Setting
The desired humidity level while Dehumidification
Away Mode is active.
Fig. 129.