Why Does My AC Smell?

If there is an unpleasant odor coming from your AC unit, it can be the result of any number of issues. Let’s take a look at some of the common reasons why your AC smells.

Common Reasons Why Your AC Smells

Let’s take a look at the most common reasons behind AC odor, and what you can do to fix the issues.

1. AC Smells Like Exhaust Fumes

Since your AC unit is not gas-powered, the sudden smell of exhaust fumes can be concerning. This can occur when fluids in the engine and other parts of your AC unit leak out, causing the exhaust fume smell.

2. AC Smells Like Feet

Homeowners typically notice the smell of stinky feet when the AC unit becomes dirty or clogged. The odor is a direct result of sitting water that isn’t draining properly and sits still. A thorough cleaning by an HVAC professional can get rid of the smell.

3. AC Smells Like A Skunk

Skunk-type smells typically indicate gas leaks somewhere in the system. Oftentimes, methyl mercaptan is responsible for smelling like a skunk’s spray getting into your ductwork and causing the odor. This dangerous gas can put your family at risk, so it’s recommended to evacuate the home when noticing the odor and calling an HVAC professional as soon as possible.

4. AC Smells Like Rotten Eggs

Typically, this type of odor in the home is the result of a dead animal. Oftentimes, birds and other rodents will take shelter in air ducts during the winter, where they can die and eventually decompose. If this is the case, turning on your AC can cause a horrible odor to filter throughout the home. Your ducts will need to be professionally cleaned to remove the cause of the smell entirely.

5. AC Smells Like Gun Powder

A burning odor smell similar to gun powder can be the result of an AC unit’s fan motor or circuit board shorting out. To get rid of the smell, it’s suggested to contact a professional.

6. AC Smells Like Mildew

This is one of the most common causes of a smelly AC unit. Chances are that mildew or fungus has started to grow in your air conditioner, if you notice a moldy odor in the air. This makes sense because ACs remove excess moisture from the home on top of cooling it.

When the moisture cannot drain properly, mold can easily develop in areas with remaining moisture. Dirty filters may also give off a scent of mildew. These situations call for an expert HVAC professional to fix the issue.