Carrier Debonair 2 Owner's Manual page 21

About Advanced Features & Operation
FAN OPERATION - Fan operation is available in four different modes:
Fan: When only the fan icon is displayed, this indicates that the fan is in
the Auto mode, will only energize during a heating or cooling cycle, and
will modulate fan speeds based on temperature demand (see page 17).
Fan , Fan , or Fan : Pressing the FAN button will cause the low,
medium, or high speed fan icon to appear (see page 9), indicating that the
fan will run continuously. The fan will de-energize if the thermostat is
placed in the Off mode or a dry contact forced unoccupied time period (see
page 18).
Notes:
1) If a Duct sensor is connected to this thermostat, then the fan should be
programmed for continuous operation (step #5, page 11). This will provide
airflow over the Duct sensor and provide more accurate temperature readings.
2) If the fan is programmed for continuous operation (step #5, page 11), the
low speed fan will run continuously when the fan is in the Auto mode, but will
de-energize if the thermostat is placed in the Off mode.
MINIMAL DISPLAY - When the thermostat is programmed for a minimal
display (step #1, page 10), a blank screen will appear. When a button is
pressed the full, normal display will appear for 10 seconds.
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