Maintaining a Central Air-Conditioner

When something goes wrong with a central air-conditioner, call a service contractor. Better yet, don't wait until a unit breaks down before making that call. Schedule a tune-up for the start of every cooling season. For example, some of the refrigerant may have leaked out -- a condition that gradually diminishes your system's efficiency.

Once a month keep an eye on the points illustrated on the next page, making sure air flows freely through the condenser, evaporator coils, and your furnace's blower unit. Examine one of the coils and you'll see that it resembles an automobile's radiator -- loops of tubing laced through a honeycomb of aluminum fins. Leaves, debris, or even a heavy accumulation of household dust on these fins chokes off the airflow upon which cooling systems depend. When you clean the fins, treat them gingerly; they bend easily, and sharp tools may puncture the relatively soft copper tubing.

Don't neglect your furnace's blower unit, either. Moving cool, heavy air strains belts and bearings.