Honeywell RTH7500D Owner's Manual page 41

Set System Setting
Press the System button to select Heat, Off or Cool:
Heat—Thermostat controls the heating system.
Off—Heating and cooling systems are both off.
Cool—Thermostat controls the cooling system.
Em. Heat (Heat Pump Systems with Auxiliary
Heat)—Thermostat controls emergency heat
and auxiliary heat, if needed. Heat Pump
compressor is not operational.
CAUTION
Equipment Damage Hazard.
Air conditioning compressor damage possible.
Do not operate cooling system when outdoor
temperature is below 50 °F (10 °C).
Set System Setting
Tue
System Auto Fan Auto
Heat Off Cool
System & Fan Schedule
41
Set To
AM
Clock & More
M22304
69-1730