Why Does My Air Conditioner Smell Like Mildew?

A malfunctioning air conditioner is a problem no homeowner wants to deal with, and for good reason. Air conditioner repairs are a nuisance. From scheduling a service call from your local HVAC contractor to possibly taking time off work for the appointment, paying for the unexpected repair costs or worse, needing a complete air conditioner replacement.

But what happens when your air conditioner starts smelling funky? In particular, why does your air conditioner smell like mildew?

Metro Heating & Cooling has the answers! Here’s a few reasons why your AC smells like mildew.

Reasons Your Air Conditioner Smells Like Mildew

Your air conditioner may smell like mildew because:

1.) Your air conditioner has a clogged drain pan – Your air conditioner’s drain pan prevents condensation build up within your cooling unit or worse, in your home. It’s a sloped pan and pipe that transports the collected condensation either outside or into your home’s plumbing system.

If your air conditioner drain pan is clogged, the water cannot drain and may cause mildew to build up inside your unit and cause your air conditioner to smell like mildew.

2.) Your air conditioner has a clogged drain pipe – Similar to the clogged drain pan, a clogged drain pipe may also cause water to collect inside your air conditioning unit and result in a mildew smell.

3.) Your ductwork collects condensation or is moist – If your home’s ductwork isn’t sealed properly, excess moisture collects in your ducts and lead to mold and mildew growth. Over time, this build up lives in your ductwork and any air passing through may be picked up and dispersed throughout your home, causing the air to have a distinct mildew scent.

4.) Your air filters are dirty or clogged – If your air conditioner’s air filter is dirty, clogged, or is too exposed to moisture, mildew may begin to grow. If your air conditioner smells like mildew, you might want to check your air filters for mold or mildew growth.

What to Do If Your AC Smells Like Mildew

If your air conditioner smells like mildew, you can get rid of the smell pretty easily.

Locate your air conditioner’s drain pan and unclog it (if it is clogged). If it is, remove the clog and add a small amount of bleach to the pan to kill the mold or mildew.

We recommend a ratio of one cap of bleach to every one gallon of water.

You can also clean the evaporator coils with your water/bleach mix. Leave the bleach and water solution on the coils and in the drain pain for a minimum of 10 minutes to kill all of the mold and mildew.

Still Smelling Mildew from Your Air Conditioner?

If you can’t get rid of the mildew smell from your air conditioner, call a heating and cooling company for air conditioner repair.

Air Conditioner Repair in St. Louis County, MO

If you live in St. Louis County, Missouri and your air conditioner smells like mildew, give us a call. One of our cooling specialists can diagnose and repair your air conditioner as soon as possible.

Phone: 314-845-5900 | Request An Estimate