Replacing the filter is only one part of maintaining your AC unit. While you can complete this yourself, most maintenance tasks should be left to a professional with the proper tools, experience, and know-how to tune up your cooling system effectively.
Checking the refrigerant charge
Inspecting and cleaning the evaporator and condenser coils
Checking and tightening all electrical connections
Inspecting the relays for wear and tear
Cleaning the drain line and condensate pump
Checking system airflow
Balancing and cleaning the blower wheel
Checking the ductwork for leaks or damage