January 20, 2015

How to fix a smelly room air conditioner

By Sears PartsDirect staff
How to fix a smelly room air conditioner.

If your air conditioner has developed an odor, don't resort to turning it off and broiling in your home; get to the root of the problem yourself by following these tips.

Before you try any of these suggestions, disconnect the power to the air conditioner.

  • Clean or replace the filter. Change the filter every 30 to 60 days, depending on how much you run the air conditioner, if you have pets and if there’s a lot of traffic through the house. Clean the filter and front grill of the unit by washing them with warm, soapy water. Use a soft, dry nylon brush to clean the coils and front grill to remove dirt and lint. Be sure to dry the filter completely before reinstalling.

  • Clean mold and mildew from coils. If you spot mold or mildew on the coils behind the filter, use coil cleaner or a warm water and bleach mixture of 20 parts of water to 1 part of bleach in a spray bottle. Flush the coils with the cleaning solution. Rinse with hot, soapy water and make sure that everything is clean and dry before turning the unit back on.

  • Check your drain. The drain pan can hold water and allow mold to grow. Use the warm water and bleach mixture to rinse and flush the drain pan and tube of mold, dirt and odors.

  • Run the fan speed on high. Running the fan on high allows the most air to pass through the coils and slow any mold growth. 

Symptoms for window air conditioners

Choose a symptom to see related window air conditioner repairs.

Main causes: dirty air filter, air conditioner is too small for the room, temperature set too cold, control failure
Main causes: lack of electrical power, bad electronic control board, wiring failure, bad temperature sensor
Main causes: bad compressor, lack of refrigerant, bad compressor start relay, electronic control board failure
Main causes: turning the air conditioner off and the back on too quickly, dirty or restricted condenser coil, compressor failure
Main causes: clogged condensate drain, air conditioner not leveled properly, leaky window air seals
Main causes: clogged drain hole, air conditioner not leveled properly
Repair guides for window air conditioners

These step-by-step repair guides will help you safely fix what’s broken on your window air conditioner.

How to replace a window air conditioner user interface control board

Control buttons or lights on the user interface control board can stop working. This repair guide shows how to replace it.

Repair difficulty
Time required
 30 minutes or less
How to replace a window air conditioner condenser fan

If the condenser fan blade is broken or the condenser fan motor won’t run, you can replace the broken parts yourself by following these instructions.

Repair difficulty
Time required
 90 minutes or less
How to replace a window air conditioner electronic control board

The electronic control board is the brain of your window air conditioner. Here’s how to replace it.

Repair difficulty
Time required
 45 minutes or less
Articles and videos for window air conditioners

Use the advice and tips in these articles and videos to get the most out of your window air conditioner.

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How to fix a smelly room air conditioner
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Learn how to remove and prevent odors in a window air conditioner.