Jackson Systems Comfort System T-21-P User Manual page 8

Mode selection
The T-21-P can control both heating and cooling. Touch the Mode box to cycle through and select
available modes. Based on equipment and thermostat configuration, mode selection can be as
follows:
Fan selection
Touch the Fan box to select
operates with a heating or cooling call. If set to Always On, the fan will run continuously. If the
thermostat is turned Off while the fan is set to Always On, the fan will switch to Automatic mode but
can be set back to Always On for constant ventilation when the thermostat is Off.
Heat Set
PM
Heat
Day
Automatic
Off - Thermostat will not call for heating or
cooling.
Heat
When heating system is running,
flashes.
Cool
When cooling system is running,
flashes.
Auto
cooling.
equipment is running.
E. Heat
systems should the compressor fail.
or Always On fan mode. In Automatic mode, the fan
Heat Set
PM
Heat
Day
7
- Thermostat only controls heating.
- Thermostat only controls cooling.
- Thermostat controls both heating and
Heat or Cool will flash when
- Emergency heat for heat pump
Heat
Cool