When your air conditioner starts putting out unusual or funky odors, it is important to take notice because it could be a sign of a major problem. Dismissing unpleasant smells coming from your air conditioning could lead to serious damage to your HVAC system 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. On the other hand, it could also indicate something mechanically wrong with the AC. Some smells are even indicative of a harmful scenario, such as a natural gas leak.

At ACS Heating and Air Conditioning, we have a nose for these sorts of things. If you smell something weird coming from your air conditioner, chances are our team of talented pros has smelled it, too—and fixed it! We’ve earned a reputation as the go-to team for air conditioning repair in Tucker.

What does a particular smell coming from your AC mean? Here are several frequent air conditioner smells and what they may mean:

The Air Conditioning Smells Like Feet

If your air conditioner smells like feet, it might be because of a buildup of bacteria or fungus in the system. When moisture builds inside the unit, it can produce an environment that is conducive to the development of bacteria and fungus. This can cause a foul odor that is often described as smelling like feet.

Another likely cause of an odor of stinky feet could be a dirty air filter. When your HVAC system's air filter becomes clogged with dirt, dust and other contaminants, it can cause poor air quality and a musty smell that resembles feet.

To fix this unpleasant situation, it's important to have a professional 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 promote good air quality and protect against the formation of bacteria and fungus.

Your AC Smells Like Rotten Eggs

If your air conditioning unit smells like rotten eggs, it could be due to 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 can be very dangerous and requires immediate attention. If you suspect a gas leak, turn off your air conditioning system, immediately open windows and doors to ventilate the area, make everyone leave the building and call your gas company or emergency services right away.

My Air Conditioner Smells Like Mildew

If your cooling system smells like mildew, it may be due to a collection of moisture inside the unit. When moisture collects inside an air conditioner, it can foster the growth of mold and mildew. This can cause a musty odor that resembles mildew.

Another possible reason for the smell may be a soiled air filter. When the air filter becomes clogged, it can result in poor air quality and a musty smell that has a resemblance to mildew.

Routine air conditioning maintenance from ACS Heating and Air Conditioning can help avoid both of these issues, because a good cleaning, inspection and filter change is a terrific way to keep your system operating at its best!

Your AC Smells Like Urine

One of the most distressing scenarios is when your AC smells like urine.

If your air conditioning smells like urine, it could be due to a variety of factors. One possible cause is a collection of bacteria or mold in the air conditioning system. This can happen when moisture accumulates in the system and creates a wet environment that favorable for bacterial growth. The bacteria can create a foul odor that is like urine.

Another potential 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 correctly, but if the drain line becomes stopped up by debris, it can cause water to back up and build up inside the unit. This can produce a musty smell that can stink like urine.

The Air Conditioning Smells Like Burning Plastic

If your air conditioning unit smells like burning plastic, it might be because of an electrical concern with the unit. After a while, the electrical elements in the air conditioning system can wear out or break, which can make a burning smell that resembles plastic.

Another possible root cause of the smell could be a foreign object lodged in the the air conditioner. If something foreign gets stuck in the air conditioning system, it can get hot and result in a smell that reminds people of burning plastic.

If you smell burning plastic coming from your cooling system, it’s worthwhile to phone a professional right away.

My Air Conditioner Smells Like Gas

If your air conditioner smells like gas, it could be due to a natural gas leak in the unit or in the surrounding area. Natural gas has a recognizable aroma, often described as smelling similar to rotten eggs or sulfur. That’s because a smell is added to natural gas so that it is easily detectable.

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

The Air Conditioning Smells Like Fish

When your AC smell like fish, it could be due to 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 disgusting odor that is often described as smelling like fish or, as mentioned earlier, it also can cause a smell like dirty feet.

Another plausible explanation for the smell could be a dead animal or other biological material stuck within 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 fix the issue, it's often necessary to have a professional inspect and clean your HVAC system. They can identify the source of the smell and take the correct steps to remove any contaminants and stop the problem from recurring.

The Air Conditioning Smells Like Vinegar

There could be multiple reasons an AC smells like vinegar. One possible cause is a dirty air filter. A second potential cause of the smell may be a refrigerant leak. Sometimes after the refrigerant leaks, it can create a chemical odor that is described as smelling of vinegar.

To fix the issue, it's essential to have a skilled tech inspect and clean your air conditioning.  If the odor continues after the cleaning and exchanging the air filter, it's best to reach back out to a professional to identify and repair any hidden issues with your air conditioning. Or, the tech can tell you if your air conditioning should be replaced.

If you are wanting to upgrade, ACS Heating and Air Conditioning can help select the correct unit to fit your home’s needs. We deliver reliable, professional air conditioner installation in Tucker.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is emitting out of your air conditioning unit, it could be caused by a refrigerant leak. If the refrigerant leaks, it can create a chemical scent that people sometimes describe as smelling like chemicals or paint thinner, vinegar or acetone.

An additional possible cause of the smell could be problems with the electrical wiring or hardware inside the air conditioning system. This can cause a burning smell that is like chemicals or burning plastic.

If you suspect a refrigerant leak or an electrical concern, it's important to turn off your air conditioning system as soon as possible and contact a professional to inspect and repair the unit. Refrigerant leaks can be hazardous and may require immediate attention to prevent injury or damage to your home.

Weird Smells Coming from Your Cooling? Call the Pros at ACS Heating and Air Conditioning

If your air conditioner reeks and you aren’t able to fix it smoothly on your own, reach out to the cooling specialists at ACS Heating and Air Conditioning. We have lots of experience working with a wide variety of HVAC systems. Our crew has fixed many air conditioning concerns over the years—including funky smells. Call us today for quality AC repair in Tucker!