Carrier Comfort Non-Programmable Owner's Manual page 7

Button Identification
a
FAN
b
MODE
c
UP
d
DOWN
Selects whether the fan operates continuously (on) or only when needed for
heating or cooling (auto)
Selects whether thermostat is set for heating, cooling, emergency heat (heat
pump system only), auto (heat and cool as needed), or off
Increases the temperature or adjusts the screen selection up when setting
advanced features
Decreases the temperature or adjusts the screen selection down when
setting advanced features
5