How to Clean an Air Conditioner
By Donald Grummett
Jack Frost is nipping at our nose and Santa Clause has just left. The eastern seaboard has just received their third blizzard for a total of over 125 cm (56 inches) of snow in one week. So, who in their right mind would be thinking about window air conditioners at this time of year?
Call me crazy, but I am.
It is a good time of year to start this project. Firstly, it keeps ones mind sharp for the coming spring. Plus, it allows you to try out those new tools you got for Christmas. Mainly though, it is a good winter project because by the time spring arrives you will be too busy to think about this job.
Very little is required to clean a window air conditioner, except lots of patience. If patience is something you lack then it is a job you should turn over to the local appliance serviceman.
- Tin can or container (old muffin tin works well also)
- Vacuum cleaner
- Long handled brush (an old toilet brush works well)
- Oil can
- De-greaser or spray detergent
- Selection of screwdrivers (Philips, Flat bladed, 1/4" socket head)
- Fin tool (optional)
- New filter (if disposable type)
Lets get started ...
- Start by removing the filter from the front grille. If it is a disposable type simply replace it with a new one. Other types are made in a plastic frame and can be cleaned and reused. To clean a reusable type lay it flat in the sink and sprinkle surface with laundry detergent. Then cover with about one inch of hot water. Just enough so the filter is submerged. Soak for 15 minutes. Remove from water and rinse with warm water. Hang up to dry while proceeding to next step.
- Next, remove the front grille from the main body of the air conditioner. They usually pivot on 2 spring clips at the bottom. It is usually removed by pulling the grille gently forward while pushing it down at the same time. If there is resistance then look for hidden screws. Look near the top edge of the grille or behind the control knob door. Once removed place the grille aside until later.
- Carefully remove metal cover of air conditioner to expose inner workings. Once all the screws are removed lift the cover straight up. Do not let it hit the other parts as it can have sharp edges. This is where the old can comes in handy (ice cube container or muffin tin works well also). Use it to keep track of all the screws you will be removing. An air conditioner will often use a number of different types and sizes of screws. Segregate them from each other or confusion will result when we start reassembly.
- Check the fan motor for any oil holes or oil plugs. If the motor has oil plugs they are usually rubber. Use caution when removing because the rubber may have become brittle. Often they will break off in the oil holes resulting in a blockage. If this occurs try to remove the broken plug by using a pin of the tip of a small screwdriver.Once the fan motor oil holes are exposed add a few drops of oil to each end of the motor body. Use a general purpose (3in1) oil or clean motor oil. A #30 oil is sufficient.The natural tendency is to over-oil. Too much lubrication is as bad as not enough. Therefore only 3 or 4 drops on both ends of the motor body is sufficient. Add the oil slowly, pausing a few seconds between each drop. If you add it too quickly over-lubrication will result.
- Use the brush to remove surface dust and dirt from the evaporator (front fins). Use only an up and down motion. Do not go side to side or allow the fins to be bent over. The fins are very soft aluminum and can be damaged easily.Once surface dirt is removed, spray with de-greaser or cleaner. There is a good product on the market called HVAC cleaner. As the name implies it is meant for Heating, Ventilation, and Air Conditioner coil cleaning. If this is not available the Fantastic Spray cleaner used in kitchens and bathrooms works quite well.Let stand about 15 minutes or as per instructions on de-greaser can. This will allow cleaner to loosen any hidden dirt. Remove dirt and excess cleaner by slowly pouring warm water into fins. Do not allow the water to enter any electrical connections or components that may be near the coil. As an added precaution cover the motor with one of the cloth rags. to protect it from the water.Do not use any form of high pressure air or water because this can drive dirt farther into fins. Also, use extreme caution as these coils are filled with high pressure refrigerant.
- Straighten any bent fins. Use a fin comb if available. If no fin comb then use something soft such as a Popsicle stick. Straightening the fins will increase the efficiency of the air flow through the coils. This adds to the overall cooling effect produced by the air conditioner.
- Repeat steps 5 and 6 for the condenser (rear fins) coil. A plastic cowling usually surrounds the condenser fins. If so, check the top edge to see if it will lift or open. If it opens this will allow easier access to the condenser fins. Again use caution because the condenser coil is also filled with high pressure refrigeran
- Wipe any dirt buildup from both fan blades using a soft rag. Do not bend blades. This would cause a vibration that would harm the motor.
- Vacuum all surfaces including front and back of grille assembly. Do not forget to vacuum underside of metal air conditioner cover. If the cover contains air holes clean them thoroughly. If necessary use a damp rag.
- Drain any water left in the base and allow it to dry for few hours.When completely dry plug in air conditioner and test operation. If everything appears okay unplug and reassemble.Once reassembly is complete, retest operation to ensure replacing the cover has not affected anything. Adding the cover will tend to twist the frame and can cause interior parts to move out of alignment. This can cause the fan to become noisy. To correct for this problem remove the cover and realign to the main body of the air conditioner. Reinstall the cover and test for noises every time 2 or 3 additional screws are added to the cover.Finally, cover air conditioner with plastic wrap or an old blanket. Store in a warm dry area. Raise it from floor slightly by placing onto a couple of pieces of wood. This will protect the floor from the metal edges of the air conditioner, and also protect the air conditioner from moisture.
Repeat this simple procedure every year. If you do, the machine will be ready for many more years of dependable service.
Copyright 2007 by Donald Grummett. All right reserved. Donald Grummett has been in the trade over 30 years as a technician, business owner, and technical trainer. Visit MG Services to learn more invaluable information about your appliances.
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Last Modified: 24 March 2020