How to Clean Mold from Air Conditioners: 9 Steps


In addition to generally causing a fairly unpleasant odour, exposure to mold in your home can also result in some serious health problem for you and your family. One of the most common, and sneakiest, places that mold is likely to grow is in your air conditioner. Unfortunately, this is also one of the best ways for the mold spores to travel, as air is continually being circulated through the unit and into your home.

Depending on the type of air conditioning unit you have, you’ll follow a different process for cleaning. If you want to learn how to clean mold from air conditioners, below are some tips to help you identify mold and to go about cleaning it.

1. Watch for warning signs

If you want to clean mold from your air conditioner, you should always be on the lookout for signs of mold in your AC or your home in general. A musty smell is always a strong indication that something is amiss.

You might also be able to see visible mold growing on the exterior or when you peak inside of the unit. If this is this the case, continue on to the following steps for cleaning instructions.

2. Unplug and inspect the unit

At the very first signs of mold, you want to immediately unplug the unit so that the mold spores are no longer able to circulate throughout your home or working environment. You can now safely inspect the unit to determine the extent of the problem.

Unplug the unit, remove the front grille cover (most snap off but some are held in place by screws), and then pull out the filter beneath the grill.

3. What to look for

You might want to grab a flashlight to get a better look inside the unit. Common signs of mold growth include clusters of brown, black, or greenish stains, some of which may appear fuzzy. Mildew, a common type of mold, produces powdery gray or white stains.

If you notice these kinds of patterns and they cover one third or less of the unit, than you’re probably in good shape to proceed with cleaning. On the other hand, if more than half or two thirds of the unit is overrun with mold, you might simply need to replace it.

4. Check the owner’s manual

Due to the fact that AC units come in so many different shapes and sizes, it is a good idea to consult the manual when it comes to the disassembly of your model. Follow the instructions carefully and make sure you keep track of all the pieces. Put small pieces in a cup or small box so that they don’t roll away or get lost while you’re cleaning.

5. Assemble the right materials and tools

Once you’re ready to clean, it is important you assemble the necessary materials and tools. Depending on how much mold there is, it is probably a good idea to wear synthetic gloves and a facial mask while cleaning.

You will also need a vacuum with a nozzle attachment, a commercial AC coil cleaner, a garden hose, and dish soap. Bleach, a large plastic bucket, and a scrubbing sponge will also come in handy.

6. Vacuum out any dust

Vacuum out as much dust and debris from the inside of the air conditioner as you possibly can. It is a good idea to use a nozzle attachment in order to remove the maximum amount.

Also, immediately empty the bag of your vacuum cleaner and change the filter. You don’t want to provide another environment for mold to continue growing in your home.

7. Spray the coils

Next you want to spray the coils, which are the U-shapes metal tubes near the front and back of the unit. This can be done with a commercial coil cleaner. The product should contain manufacturer’s instructions regarding how long it needs to be left on the surface in order to dissolve anything that has accumulated on the coils.

Cleaning the coils in a necessary step in eliminating mold because the small areas between each one provides an ideal breeding ground.

8. Scrub, scrub, scrub

How you want to fill a plastic bucket with hot water and bleach so you can get scrubbing. Use a sponge to remove any visible traces of mold before allowing the unit to air-dry completely. Don’t rush to reassemble, it could take up to 24 hours for all the parts to dry.

9. Prevent mold growth in the future

Despite your cleaning efforts, if you’ve had mold in your AC unit once, it is unfortunately likely that it could develop again. Mold spores may have remained within various parts of the inner unit that you will be able to reach.

Remember that dust gives these spores a chance to adhere and grow, so it is important to remove the grille and filter every few weeks and vacuum the interior of the unit to keep dust from settling.