Why Your Air Conditioner Smells and How to Fix It

June 20, 2023

When your air conditioner starts putting out weird or gross odors, it is important to take notice because it could be a sign of a significant problem. Dismissing unpleasant smells coming from your cooling system could lead to further damage to your AC or even pose a risk to your health and safety.

Depending on what you're smelling, the root of the problem may be bacteria or fungus in the system. Other times, it could also sign something mechanically wrong with the air conditioner. Some smells are a sign of a hazardous problem, such as a natural gas leak.

At Cool Air Solutions, we are experienced at getting to the root cause of stinky smells. If you smell something peculiar coming from your AC, chances are our team of skilled professionals has smelled it, too—and fixed it! We’ve earned our reputation as the premier company for air conditioning repair in Murrieta.

What does a certain smell coming coming from your cooling system mean? Here are a few typical air conditioner odors and what they might mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it might be caused by a buildup of bacteria or fungus in the system. When moisture collects inside the unit, it can create an environment that is conducive to the development of bacteria and fungus. This can result in a nasty odor that is often described as smelling like dirty feet.

Another possible reason for the smell could be a dirty air filter. If an air filter becomes choked with dirt, dust and other debris, it can lead to poor air quality and a musty smell that bears a resemblance to feet.

To fix this unpleasant situation, it's important to have an experienced specialist inspect and clean your air conditioning system, including the evaporator coil, drain pan and condensate drain line. It's also important to replace the air filter regularly to provide good air quality and prevent the growth of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioning equipment smells like rotten eggs, it could be caused by a natural gas leak in the unit or in the surrounding area. Natural gas has a distinct odor, often described as smelling like rotten eggs or sulfur, that is added to it to make it easily detectable.

A natural gas leak is very dangerous and requires immediate attention. If you suspect a gas leak, turn off your air conditioning system, immediately open windows and doors to air out the area, get everyone out of the building and call your gas company or emergency services immediately.

My Air Conditioner Smells Like Mildew

If your cooling system smells like mildew, it could be due to a accumulation of moisture inside the unit. When moisture forms inside an air conditioner, it can cultivate the growth of mold and mildew. This can cause a musty stench that resembles mildew.

Another possible explanation for the smell could be a soiled air filter. If the air filter becomes clogged, it can cause poor air quality and a musty smell that resembles mildew.

Regular air conditioning maintenance from Cool Air Solutions can help protect against both of these situations, because a good cleaning, inspection and filter change is a great way to keep your system working at its best!

My Air Conditioner Smells Like Urine

One of the most unpleasant scenarios is when an air conditioner smells like urine.

If your air conditioner stinks like urine, it could could be caused by multiple factors. One possible cause is a collection of bacteria or mold in the air conditioning system. This can happen in the event that moisture accumulates in the system and creates a wet environment that is conducive to bacterial growth. The bacteria can create a foul odor that is like urine.

Another potential cause of the stink could be a blocked drain line. The condensation that forms inside the air conditioning unit needs to drain away properly, but if the drain line becomes choked with debris, it can cause water to back up and accumulate inside the unit. This can produce a musty smell that resembles urine.

My Air Conditioner Smells Like Burning Plastic

If your air conditioning system smells like burning plastic, a possible cause could be an electrical problem with the unit. After some time, the electrical elements in the air conditioning system can wear out or bust, which can make a burning smell that resembles plastic.

Another possible root cause of the smell could be a foreign object that somehow got in the the air conditioner. If something foreign gets trapped in the air conditioning system, it can become hot and cause a smell that reminds people of burning plastic.

If you notice something that smells like burning plastic coming from your cooling system, it’s worthwhile to contact a professional right away.

My Air Conditioner Smells Like Gas

If your air conditioner smells like gas, it could be because of a natural gas leak in the unit or in another part of your home. Natural gas has a recognizable aroma, often described as smelling like rotten eggs or sulfur. That’s because an odor is incorporated into natural gas to make it easily detectable.

As stated earlier, a natural gas leak can be VERY hazardous and needs immediate attention. When you suspect a gas leak, turn off your air conditioning system, open windows and doors to air out the home, get everyone out of the building and phone your gas company or emergency services right away.

Why My Air Conditioner Smells Like Fish

When your air conditioner smell like fish, it could be due to a build-up of bacteria or mold in the unit. Moisture produces an environment that fosters the growth of bacteria and mold. This can cause a foul odor that is often described as smelling like fish or, as mentioned earlier, it also can cause a smell like dirty feet.

Another possible cause of the smell could be a dead animal or other biological material trapped inside the air conditioning system. This often can take place if an animal such as a mouse or bird is trapped inside the unit and dies.

To correct the issue, it's often necessary to have a professional check out and clean your cooling system. They should be able to find the source of the smell and take the proper steps to remove any contaminants and keep the problem from recurring.

Why My Air Conditioner Smells Like Vinegar

There could be numerous reasons a home's AC smells like vinegar. One possible cause might be a dirty air filter. A second potential cause of the smell might be a refrigerant leak. If the refrigerant leaks, it can make a chemical odor that is described as smelling of vinegar.

To fix the issue, it's beneficial to have a skilled specialist examine and clean your air conditioning. If the odor persists after the cleaning and changing of the air filter, it's best to reach back out to a professional to find and repair any underlying issues with your air conditioning. Or, they can tell you if your air conditioning should be replaced.

If you are wanting to upgrade, Cool Air Solutions can help locate the correct unit to fit your home’s needs. We provide trustworthy, skilled air conditioner installation in Murrieta.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming from your air conditioning unit, it could be the result of a refrigerant leak. When the refrigerant leaks, it can create a chemical odor that people sometimes describe as smelling like chemicals or paint thinner, vinegar or acetone.

An additional possible reason for the smell could be something wrong with the electrical wiring or components inside the air conditioning system. This can result in a burning smell that is like chemicals or burning plastic.

If you think your system has a refrigerant leak or an electrical issue, it's important to shut off your air conditioning system right away and contact a professional to inspect and repair the unit. Refrigerant leaks can be dangerous and may require immediate attention to prevent injury or damage to your house.

Strange Smell Coming from Your AC? Call the Pros at Cool Air Solutions

If your air conditioner stinks and you aren’t able to fix it easily on your own, contact the cooling professionals at Cool Air Solutions. We have years of experience working with a wide variety of air conditioning systems. Our crew has fixed many air conditioning concerns over the years—including weird smells. Call us today for quality AC repair in Murrieta!