Honeywell RTH6400 - Manual (Page 10)

Operating Manual
69-22ES—0 8
Select the system setting
Press the SYSTEM button to select Heat, Cool
or Off.
• Heat: Thermostat controls only the
heating system.
• Cool: Thermostat controls only the
cooling system.
• Off: Heating and cooling systems are off.
• Auto: Thermostat automatically selects
heating or cooling depending on the
indoor temperature.
CAUTION: EQUIPMENT DAMAGE
HAZARD. To prevent possible
compressor damage, do not operate
cooling system when outdoor
temperature is below 50°F (10°C).
Note: The Auto setting may not
appear, depending on how your
themostat was installed.
M28407
Set Clock/Day/
Schedule
Auto
Fan System
Heat
M28408
Set Clock/Day/
Schedule
Auto
Fan System
Cool