Select Fan Setting (Auto/On) - Honeywell RTH6400 Operating Manual

Select the fan setting
Fan
Set Clock/Day/
Auto
Schedule
Fan
Set Clock/Day/
Schedule
System
Heat
M28405
System
On Heat
M28406
RTH6400 Programmable Thermostat
Press the FAN button to select 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.
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