Honeywell PRO TH4000 - Manual (Page 10)

Operating Manual
8 69-1760EFS—01
ENGLISH
M29473
Fan switch
Set the FAN switch to Auto or On.
In “Auto” mode (the most commonly used
setting), the fan runs only when the heat-
ing or cooling system is on.
If set to “On,” the fan runs continuously.
Set FAN switch to choose whether the fan
runs continuously or only as needed.