Room Air-Conditioner Maintenance

Keeping your cool–no matter how hot it gets.


- Reinstallation
- Operation Tips
- How-to Photos

Summer's here and your room air conditioner is laboring hard. You can help the appliance work more efficiently through the months ahead by following a simple maintenance program, and you might even save a little money on your utility bill.

Effectively keeping up some appliances -- high-efficiency gas or oil furnaces, for example--requires a technician. Fortunately, a basic room air conditioner can be maintained by a homeowner who has only a few hand tools and a shop vacuum.

To begin, unplug the air conditioner and remove the front grille and filter (Figs. 1 and 2). The filter traps pollen, dust and dirt, and if it's clogged, you won't get maximum cooling performance. Wash it with a mixture of warm water and soap. If the filter has deteriorated, replace it. Your local appliance store, hardware store or home center may be able to supply you with the exact size and type of replacement part you need. If not, several manufacturers make filters that can adapt to many brands of air conditioners. These are cut to fit with a pair of scissors. One source for such filters is the General Electric Consumer hotline: (800) 626-2000. A cut-to-fit GE filter costs $8.05 with shipping (state tax is extra).

Remove the air conditioner from the window and clear away any accumulated debris from the windowsill. Take the appliance out of its cabinet. (Some will slide out of the cabinet, but on most, the cabinet is held in place with screws.) Remove the screws and put them aside (Fig. 3). Then, use a shop vacuum and crevice tool to get rid of leaves and debris from within the air conditioner (Fig. 4).

To clean the inside (Fig. 5), bring the appliance outdoors and use a paintbrush and some soapy water. Put plastic bags over the fan motor, electrical control box and compressor. Secure the plastic with duct tape. Hose the inside clean (Fig. 6), and make sure the base, coils and pan for condensate are clean as well.

When you've finished, remove the plastic bags and dry off the air conditioner with a fresh cloth. Allow the remaining moisture to evaporate, or you can accelerate the drying process by blowing out moisture with a can of compressed air. Single-use cans of compressed air are available through tool catalogs and some hardware stores. You can also try using a rechargeable air tank, which is sold at hardware stores, home centers and auto parts stores.

When the appliance is dry, reassemble and reinstall it in the window, following the general guidelines mentioned below. It's a good idea to allow the air conditioner to remain idle for one full day--just to be sure that the machine is thoroughly dry before you begin running it.


Now that the maintenance of your air conditioner is complete, it's time to start thinking about ways of getting maximum performance and durability out of the appliance.

Many people mistakenly believe that air conditioners need to be pitched down, slightly out of level, to help them drain condensate. Actually, the exact opposite is true. An air conditioner should be installed so it's level. These appliances are designed so that condensate collects below the fan and runs into the slinger ring, which is made of sheetmetal and is part of the fan assembly. The bottom of the ring acts like a gutter to collect condensate. The fan then picks the water out of the ring and slings it against the condenser coils.

Recycling the condensate in this manner increases the coils' cooling capacity. Check the air conditioner for level -- front to back and side to side -- when you install the unit.

If the appliance's side panels are cracked, now is the time to replace them. In some cases, you can get a single side panel from an appliance store (each side costs about $15 to $30), or you may have to buy both sides -- and the guides that they run in. Some people opt not to replace the side panels when they wear out. Instead, they remove the panels and screw clear plastic sheet (Plexiglas, for example) over the runners. This also lets in a little extra daylight.

Take steps to seal the area where the window closes on top of the air conditioner. In many instances, the foam strip that came with the appliance will have worn out. The gap left by an improper seal is energy inefficient, not to mention an entryway for bugs. Appliance stores sell kits called Air Conditioner Window Foam. These are nothing more than bags with foam strips that have peel-and-stick backing. If you can't find one of these kits, you may substitute adhesive-backed weatherstripping. Weatherstripping can also be used as a vibration damper when a storm window or screen rests on the top of the appliance.

If your air conditioner is installed in a vinyl replacement window, think about using a wood reinforcement strip below the appliance to distribute its weight. An air conditioner is heavy enough to distort some vinyl replacement windows. Also, consider screwing L-brackets into the window channel rather than letting the unit rest against the window sash. Again, the brackets bear the weight of the air conditioner -- not the replacement sash.

If you have a problem with birds building nests under the air conditioner, install a thin, exterior-grade strip of plywood or a piece of painted solid wood to block their entry.

Operation Tips

Finally, there are things you can do to help reduce the heat load on your air conditioner. One sounds obvious, but it's often overlooked: Draw blinds or drapes on the sunny side of the house to block out the Sun's rays. In hot, sunny climates, awnings can also substantially reduce heat gain. Further, keep the garage door shut and close all the windows in the house.

Along similar lines, the same kinds of weatherstripping that prevent heat loss in the winter also prevent heat gain in the summer. Properly weatherstripped doors and windows, combined with attic insulation, are your best defense against wasted energy.

And don't overlook ventilation. Attic, ridge and soffit vents should be cleared of bird and insect nests so that attic heat can escape.

Winterizing your air conditioner at the end of the season is simple. If you leave it in the window, wrap it with plastic sealed with duct tape, or buy an air-conditioner cover. With stay-in-place machines, also remember to close the vents. If you take the appliance out of the window, be careful not to bend or damage the cooling fins on the back of it. And don't store an air conditioner on a garage floor, where it could come into contact with corrosive de-icing salts that can drip off of a car's tires.

How-to Photos

1-- The first two steps in air-conditioner maintenance are unplugging the appliance and then removing its front grille.
2--Remove filter and wash it thoroughly. If filter particles come loose, or if the part is cracked or has many holes, replace it.
3--Next, remove the side panels from the air-conditioning unit, then take out the screws that are holding the cabinet.
4--Use a shop vacuum and crevice tool to clean any dust and debris that may have accumulated inside the air conditioner.
5--Cover all electrical components with plastic bags. Then, clean the inside of the unit with soapy water and a paintbrush.
6--Hose down the appliance and let it dry. Reassemble and reinstall it, but wait a day to make sure it's dry before turning it on.