Inspect unit for proper refrigerant level and adjust if necessary

Clean dirt, leaves and debris from inside cabinet

Inspect base pan for restricted drain openings—remove obstructions as necessary

Inspect coil and cabinet—clean as needed

Inspect fan motor and fan blades for wear and damage—on older models lubricate as needed

Inspect and clean blower assembly (includes blower housing, blower wheel and motor)

On older models, lubricate motor and inspect and replace fan belt if needed

Check combustion blower housing for lint and debris and clean as necessary

Inspect evaporator coil, drain pan and condensate drain lines. Clean as needed

Inspect for gas leaks in gas furnaces

Inspect burner assembly—clean and adjust as needed.

Inspect control box, associated controls, wiring and connections

Clean or replace air filters

Inspect conditioned airflow system (ductwork)—check for leaks