UPPER Button

When UPPER button is pressed, UPPER LED will come on, and selected temperature will be displayed for 5 seconds. Blower motor operates, and speed can be manually controlled using control knob. Programmer applies vacuum to defrost A/C door vacuum actuator and one side of heater-A/C-bi-level vacuum door actuator. See Figure. Outside/recirculated air door actuator is in outside air position. Defrost-A/C door actuator and heater-A/C-bi-level door actuator are in A/C position. Programmer will direct air from vent outlets.