Which equipment requires regular (or preventive) maintenance?

All heating and cooling equipment require annual professional tuneup. Inspections on boilers and furnaces should include ductwork, pipes, dampers, valves, the chimney, registers, radiators, pumps, blowers, fuel lines and the oil tank. Heat pump and air conditioning unit inspections should also include an examination of the fan, compressor, indoor coils, outdoor coils, and refrigerant lines.