How to Remove Foul Smell From Your Air Conditioner

How to Remove Foul Smell From Your Air Conditioner

A well-functioning air conditioner should neither create a racket nor emit a smell. If you experience any air conditioner smells, it is clear that something is not right. A smell could signal minor damage or a more serious one that needs to be addressed immediately.

Let’s look at some of the familiar smells you may get from your AC and how to get rid of them:


Accumulation of dust on the filters can become mold due to moisture. Mold can also clog up your condensate drain line and cause your air conditioner to smell musty.

How to Clean

  1. Use a soft brush to dust the insides of the unit.
  2. Clean the vent and duct with a mild cleaning solution.
  3. Wipe out all the water from the unit.
  4. Let it dry for a couple of hours before use.

Dead Animals

When your AC is not in use for a long time, rodents or reptiles may get into it and eventually die inside it. Dead animals can be the cause of a stench in your AC.

How to Clean:

  1. Remove the outcast and wear latex gloves to remove the dead animal.
  2. Spray a foaming coil cleaner on the air conditioner’s coil.
  3. Leave it for 10-15 minutes to loosen any dirt.
  4. Rinse the coil until all the dirt is removed.
  5. Let the coil dry completely before replacing the outer case.

Cigarette Smoke

If you regularly smoke indoors with your AC on, your AC will eventually smell stale cigarettes when turned on.

How to Eliminate: 

  1. Change your AC filters every 60 days.
  2. Smoking outdoors is a better way to deal with this smell.


If there is a block or rupture in your sewer vent pipe, this could cause your AC to smell like raw sewage and could be hazardous to your health.

How to Eliminate:

  1. Call in a plumber to repair your drainage system.
  2. If the smell persists, contact an HVAC technician immediately.

Rotten Eggs

If your AC smells of rotten eggs or sulfur, there could be a gas leak gas making its way into your ventilation. This is a serious problem.

How to Handle:

  1. Turn off your gas supply immediately.
  2. Open all windows and doors to let out the gas.
  3. Contact your gas company immediately to rectify the problem. 

Oil or Burning Plastic

An oily smell indicates an oil leak or malfunctioning of your unit’s oil burner. A burnt smell could mean that some component of your AC is overheating.

How to Remove 

In both scenarios, it’s best to call an expert in HVAC services to check your AC unit thoroughly. Regular maintenance of your AC will take care of such problems. 


While attending to minor issues with your air conditioner by yourself may seem convenient, we would not recommend it unless you have prior experience.

You Can Rely on Us

Whether it’s a smell, water leak, or a sound coming from your AC, we are here to help you resolve it immediately. If you schedule a visit online, our technician will visit your home to evaluate and attend to your problem. We provide AC Repair in Pasadena, Severna Park, Annapolis, MD, and surrounding areas. Call us at (443) 250-9917 or send us a message, and we’ll get in touch with you soon.