Four Portable Air Conditioner Problems

A portable air conditioner against a white background.

If you don't have central air, portable air conditioners can be a great solution for those hot summer days. However, like any appliance, air conditioners need to be maintained during the off-season to ensure that they work properly when you do need them.

Following are four portable air conditioner problems to look out for and how to solve them.

1. Your Air Conditioner Won't Start or Stops Operating

There are numerous reasons for an air conditioner to either not start or cease to operate.

The first thing you should check is whether the unit is plugged in and if the outlet is receiving power. You should also check to make sure the power cord is not damaged in any way.

The next thing to check is whether your unit is on a timer. A timer can cause the unit to stop working and may prevent it from starting all together.

Lastly, you should check the temperature at which your portable air conditioner is set. If the ambient temperature is lower, the unit will either not turn on or will turn off quickly.

2. Your Air Conditioner Does Not Cool the Room

On a really warm day, it will take some time for an air conditioner to do its work and cool down a room. Especially if it's a large room or a room with high ceilings. However, if your room still feels quite warm after the air conditioner has been running for 30-60 minutes, you may have a problem on your hands.

The biggest problem is likely that your air conditioner is too small for the size of the room you are trying to cool. Portable air conditioners are sized according to their BTU ratings. If your air conditioner has the wrong BTU rating, it won't work efficiently. Too large of a BTU and the air conditioner will constantly cycle on and off. Too low of a BTU and your air conditioner will never be able to get the room as cool as you would like.

When purchasing a portable air conditioner, make sure you have the dimensions of the room you will be using it in. Most portable air conditioner boxes will outline the room size that the particular model will work for. If you find your room is between sizes, opt for the bigger model.

If your portable air conditioner is the right size for your room, it's possible that the ambient temperature is too high. Portable air conditioners work by pushing cool air into a room and venting hot air, through the units compressor, to the outside. This constant venting can cause a pressure imbalance that will pull in warm air from other parts of the house. To solve this, make sure any doors to the room are closed. If the room receives a lot of sun, be sure to cover the windows with curtains or shades.

If you find that your portable air conditioner still does not work properly, it's possible that it needs a good cleaning. Read on for more details.

3. Your Air Conditioner Has Little Air Flow

The most common cause of a lack of air flow is a dirty filter. The interior of portable air conditioners can get quite dirty and dusty.

Referencing the manual that came with your portable air conditioner, remove the filter and clean it. You may also want to take this time to wipe down any exposed interior areas with a damp cloth.

Another reason your portable air conditioner may lack air flow is the presence of frost on the evaporator coils. When water doesn't drain properly from a portable air conditioner, it builds up and can freeze around the coils. This prevents air flow.

If you saw any amount of frost on the interior of your portable air conditioner when you removed the filter, you should keep your air conditioner off and let it defrost. Wipe out any excess water with a rag. After everything has dried, you should be able to run your air conditioner properly.

4. Your Air Conditioner Has a Musty Smell

A musty smell coming from your air conditioner likely means you have a mold or mildew problem. Mold and mildew tend to grow in wet places. If your portable air conditioner is retaining water, it creates the perfect breeding ground for spores.

Like above, you'll want to reference your manual and inspect the interior of your portable air conditioner. Check the filter, evaporator coils, drain line, and drain pan. If you see mold or mildew, you'll want to give your air conditioner a thorough cleaning.

Wear a mask and clean all reachable areas with a cleaner that is made specifically for mold and mildew.

If you follow the above steps and keep your portable air conditioner protected in the off season, it should run smoothly for years to come.

If the above steps don't work, it may be time to call in a professional or purchase a new portable air conditioner.