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

Depending on the cause of the odor, the culprit could be bacteria or fungus in the system. On the other hand, it could also indicate something mechanically wrong with the air conditioner. Some smells are a warning of a dangerous problem, including a natural gas leak.

At Scott Temperature, we have a nose for these sorts of things. If you smell something peculiar coming from your air conditioner, you can bet that our team of qualified pros has smelled it, too—and fixed it! We’ve earned a reputation as the go-to team for air conditioning repair in Lawrence.

What does a certain smell billowing out of your cooling system mean? Here are several typical air conditioner aromas and what they could mean:

The Air Conditioning Smells Like Feet

If your air conditioner smells like feet, it can be due to a buildup of bacteria or fungus inside of it. When moisture accumulates inside the unit, it can create an environment that is conducive to the growth of bacteria and fungus. This can cause a bad odor that is often described as smelling like feet.

Another likely explanation for the stench of dirty feet could be a dirty air filter. When your HVAC system's air filter becomes clogged with dirt, dust and other particles, it can cause poor air quality and a musty smell that resembles feet.

To fix this issue, it's important to have a quality service tech inspect and clean your air conditioning system, including the evaporator coil, drain pan and condensate drain line. It's also important to change the air filter regularly to provide good air quality and restrict the development of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your reeks of rotten eggs, it may be caused by a natural gas leak in the unit or in the surrounding area. Natural gas has a unique odor, often described as smelling like rotten eggs or sulfur, which is because of a substance 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 allow gas to escape the area, make everyone leave the building and call your gas company or emergency services immediately.

My Air Conditioner Smells Like Mildew

If your AC is giving off an odor like mildew, it could be due to a accumulation of moisture inside the unit. When moisture collects inside the air conditioning system, it can foster the growth of mold and mildew. This can cause a musty stench that it similar to mildew.

Another possible explanation for the smell may be a dirty air filter. When the air filter becomes clogged, it can result in poor air quality and a musty smell that resembles mildew.

Regular air conditioning maintenance from Scott Temperature can help protect against both of these problems, because a good cleaning, inspection and filter change is a great way to keep your system operating at its best!

Your AC Smells Like Urine

One of the most undesirable scenarios is when the air coming out of your HVAC system smells like urine.

If your air conditioner smells like urine, it could be due to a variety of factors. One likely cause is a collection of bacteria or mold in the air conditioning system. This can happen if moisture accumulates in the system and creates a damp environment that can promote bacterial growth. The bacteria can emit a foul odor that it similar to urine.

Another possible cause of the scent of urine could be a plugged drain line. The condensation that forms inside the air conditioning unit needs to drain away effectively, but if the drain line becomes clogged with debris, it can cause water to back up and collect inside the unit. This can produce a musty smell that is sometimes described as smelling of urine.

My Air Conditioner Smells Like Burning Plastic

If your AC smells like burning plastic, a possible cause could be an electrical issue with the unit. Over time, the electrical parts in the air conditioning system can wear out or break, which can produce a burning smell that resembles plastic.

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

If you think you smell burning plastic coming from your air conditioner, it’s essential to contact a professional right away.

The Air Conditioning Smells Like Gas

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

As stated earlier, a natural gas leak can be VERY hazardous and requires immediate attention. When you suspect a gas leak, turn off your air conditioning system, open windows and doors to air out the home, leave the building and call your gas company or emergency services as soon as possible.

Your AC Smells Like Fish

If your air conditioning equipment smell like fish, you may have a situation where there's a build-up of bacteria or mold in the unit. Moisture produces an environment that promotes 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 create a smell like dirty feet.

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

To solve the issue, it's worthwhile to have a professional inspect and clean your HVAC system. They can find the source of the smell and take the proper steps to remove any contaminants and keep the problem from recurring.

The Air Conditioning Smells Like Vinegar

There could be several reasons a home's air conditioner smells like vinegar. One possible cause might be a plugged air filter. One other possible cause of the smell could be a refrigerant leak. When the refrigerant leaks, it can make a chemical odor that is described as smelling of vinegar.

To fix the issue, it's important to have a skilled specialist inspect and clean your air conditioning.  If the odor continues after the cleaning and replacing of the air filter, it's best to reach back out to a professional to identify and repair any underlying issues with your air conditioning. Or, the mechanic can tell you if your air conditioning needs to be replaced.

If you are looking to upgrade, Scott Temperature can help select the right unit to fit your home’s needs. We deliver trustworthy, professional air conditioner installation in Lawrence.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming from your air conditioner, it could be caused by a refrigerant leak. When the refrigerant leaks, it can create a chemical aroma that is often described as smelling like chemicals or paint thinner, vinegar or acetone.

One other possible cause of the smell could be an issue with the electrical wiring or hardware inside the air conditioning system. This can produce a burning smell that resembles 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 harmful and may require immediate attention to prevent injury or damage to your house.

Strange Smell Coming from the Air Conditioning? Call the Pros at Scott Temperature

If your air conditioner smells nasty and you aren’t able to fix it simply on your own, reach out to the cooling specialists at Scott Temperature. We have plenty of experience working with a wide variety of AC systems. Our crew has fixed countless air conditioning problems throughout the years—including weird smells. Call us today for quality AC repair in Lawrence!