When your air conditioner starts emitting unusual or gross odors, it is a good idea to take notice because it could be a sign of a significant problem. Disregarding unpleasant smells coming from your cooling system 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. In other cases, it could also sign something mechanically wrong with the AC. Some smells are a sign of a hazardous scenario, like a natural gas leak.

At Appalachian Heating, we are experienced at getting to the root cause of stinky smells. If you smell something odd coming from your AC, you can bet that our team of skilled specialists has smelled it, too—and fixed it! We’ve earned a reputation as the go-to team for air conditioning repair in Mount Hope.

What does a particular smell billowing coming from your AC mean? Here are a few frequent air conditioner aromas and what they might mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it could be because of a buildup of bacteria or fungus inside of it. When moisture collects inside the unit, it can create an environment that is conducive to the growth of bacteria and fungus. This can result in a foul odor that is often described as smelling like feet.

Another likely reason for the stench of dirty feet may be a dirty air filter. When the air filter becomes filled with dirt, dust and other debris, it can result in low air quality and a musty smell that it similar to the smell of feet.

To correct this unpleasant situation, 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 promote good air quality and protect against the growth of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your smells like rotten eggs, it may be due to a natural gas leak in the unit or in the surrounding area. Natural gas has a recognizable odor, often described as smelling like rotten eggs or sulfur, which is added to it to make it easily detectable.

A natural gas leak is extremely 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, evacuate the building and call your gas company or emergency services at once.

The Air Conditioning Smells Like Mildew

If your AC smells like mildew, it could be due to a buildup of moisture inside the unit. When moisture accumulates inside an air conditioner, it can cultivate the growth of mold and mildew. This can cause a musty stench that it similar to mildew.

Another possible cause of the smell might be a dirty air filter. When the air filter becomes clogged, it can lead to poor air quality and a musty smell that resembles mildew.

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

The Air Conditioning Smells Like Urine

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

If your air conditioner stinks like urine, it could could be caused by multiple factors. One potential cause is a accumulation of bacteria or mold in the air conditioning system. This can happen when moisture accumulates in the system and creates a wet environment that can promote bacterial growth. The bacteria can create a foul odor that some people describe as smelling like urine.

Another potential cause of the smell 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 build up inside the unit. This can produce a musty smell that resembles urine.

Your AC Smells Like Burning Plastic

If your AC smells like burning plastic, it might be because of an electrical concern with the unit. After some time, the electrical components 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 stuck in the HVAC system. If something foreign gets stuck in the air conditioning system, it can get hot and emit a smell like burning plastic.

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

The Air Conditioning Smells Like Gas

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

As we said before, a natural gas leak can be VERY harmful and needs 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.

Your AC Smells Like Fish

Should your air conditioning equipment smell like fish, this could be a sign of a build-up of bacteria or mold in the unit. Moisture causes 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 cause a smell like dirty feet.

Another potential cause of the smell could be a dead animal or other biological material stuck in the air conditioning system. This often can happen if an animal such as a mouse or bird becomes trapped inside the unit and dies.

To fix the issue, it's worthwhile to have a professional inspect and clean your cooling system. They will be able to determine the source of the smell and take the proper steps to remove any contaminants and stop the problem from recurring.

Why My Air Conditioner Smells Like Vinegar

There could be several reasons a home's air conditioner smells like vinegar. One possible cause might be a dirty air filter. A second likely cause of the smell might be a refrigerant leak. If the refrigerant leaks, it can make a chemical odor that resembles vinegar.

To fix the issue, it's beneficial to have a skilled tech look at and clean your air conditioning.  If the odor continues after the cleaning and changing of the air filter, it's best to reach back out to a professional to diagnose and repair any persistent issues with your air conditioning. Or, they can tell you if your air conditioning needs to be replaced.

If you are wanting to upgrade, Appalachian Heating can help find the right unit to fit your home’s needs. We provide trustworthy, expert air conditioner installation in Mount Hope.

The Air Conditioning Smells Like Chemicals

If the smell of chemicals is emitting out of your air conditioner, it could be due to a refrigerant leak. In a situation where the refrigerant leaks, it can create a chemical scent that is often described as smelling like chemicals or paint thinner, vinegar or acetone.

Another possible cause of the smell could be something wrong with the electrical wiring or hardware inside the air conditioning system. This can produce a burning smell that it similar to chemicals or burning plastic.

If you think your system has a refrigerant leak or an electrical issue, 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 dangerous and may require immediate attention to avoid injury or damage to your home.

Weird Smells Coming from Your AC? Call the Pros at Appalachian Heating

If your air conditioner stinks and you aren’t able to fix it easily on your own, reach out to the cooling experts at Appalachian Heating. We have lots of experience working with a wide variety of AC systems. Our crew has fixed countless air conditioning troubles over the years—including funky smells. Call us today for quality AC repair in Mount Hope!