Honeywell RTH221 - System switch (Heat;Cool)

Programmable Thermostat RTH221
7
System switch (Heat/Cool)
Use the System switch to place the system in
one of the following modes:
• Cool: System is in Cooling mode.
• Off: System is off.
• Heat: System is in Heating mode.
CAUTION: EQUIPMENT DAMAGE HAZARD.
Do not use Cooling mode when the outdoor temperature is below 50°F (10°C).