A central air system uses the same ductwork, fan, and controls as the forced-air furnace, so some of the maintenance requirements are the same.
A qualified service technician should also:
Inside unit
- Inspect and clean evaporator coil, drain pan, and condensate drain lines
- Inspect control box, wiring, and connections for wear or damage
- Ensure insulation on tubing is intact
Outside unit
- Inspect for proper refrigerant level
- 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 control box, wiring, and connections for wear or damage
- Inspect compressor and tubing for damage
- Ensure penetrations through the house are properly sealed
Additional Recommendation
Additionally, there are many things that home owners can do to keep their air conditioners operating efficiently and safely:
- As with the furnace, air filters need to be changed per manufacturer’s recommendations. Restricted airflow can cause evaporator coil to freeze up, reducing efficiency and potentially damaging components.
- The area around the outside unit must be kept free of foliage or anything that can block airflow to the unit.
- The coils of the outside unit can get clogged from leaves, dust, or other debris, thus reducing efficiency. Periodically spraying with a hose can ensure proper operation.
- Window units require filters to be cleaned, drain lines to be clear and held away from siding, and proper sealing between the window and the unit.
- Ductless and high velocity systems also have filters that need cleaning or replacing.
