How to Service a Window Air Conditioner Unit

Warning:
Make sure the unit is unplugged. The capacitor can hold a charge and shock you. Use caution when checking the wires. The fins on the coils are very fragile. Do not bend them when you handle the unit.

Take the unit outside and place it on a suitable work bench. Remove the screws holding the housing to the base. I had to start with the rear panel. Your A/C might be different. Remove the housing to expose the coils. There are two fans that force air through the coils. Only one side would be dirty so check both sides of the coils for dirt build up. You should be able to rinse the coils with a garden hose. You can use a chemical cleaner if you have stubborn build up. Chemical cleaners are available at a plumbing supply shop or maybe your local home store.

Once both coils are clean you can stand the unit on it's side and rinse out the bottom pan. There will probably be a lot of gunk caked in the pan. Plenty of water should clean it out. Try not to soak the electronics while you are washing out the coils and the pan. Don't forget to clean the filter and the housing.

Finally you can visually check the electrical connections. Most window air condition failures come from a loose wire not the loss of refrigerant. When the wire becomes loose it gets hot and eventually burns up. Look for discolored and brittle wire connections. If you find a loose wire it can be repaired easily. Use pliers to tighten the connector make sure it fits snug when you slip it back onto the lug. If it is already burned up you can splice on a new section of wire and a new connector.

Allow the unit to sit upright and dry for several hours after it was on it's side. The oil needs a chance to drain back out of the coils or you could cause damage to the compressor. Reassemble the housing in the opposite order that it came apart. Do not bend the coil fins during reassemble. If any fins are bent the can be carefully straightened with a small screw drive or a fin tool from a plumbing shop or auto parts store. Be sure to click the icon on the corner of the picture on the first page to view all of the photos in this article.