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 ignition system and safety controls—clean and adjust as needed
Inspect heat exchanger or heating elements
Inspect flue system—check for proper attachment to the furnace, any dislocated sections, and for signs of corrosion. Replace if necessary.
Inspect control box, associated controls, wiring and connections
Clean or replace air filters
Inspect conditioned airflow system (ductwork)—check for leaks