Why Your Air Conditioner Smells and How to Fix It

When your air conditioner starts spewing weird or unappealing aromas, it is a good idea to take notice because it could be a sign of a major problem. Dismissing unpleasant smells coming from your air conditioner could lead to serious damage to your AC or even pose a risk to your health and safety.

Depending on the smell, the culprit may be bacteria or fungus in the system. Other times, it could also signal something mechanically wrong with the AC. Some smells are even indicative of a dangerous problem, like a natural gas leak.

At Classic Air, we have a nose for these sorts of things. If you smell something peculiar coming from your AC, you can bet that our team of talented specialists has smelled it, too—and fixed it! We’ve earned the reputation as the go-to team for air conditioning repair in Columbus.

What does a particular smell wafting out of your air conditioning mean? Here are some frequent air conditioner odors and what they might mean:

Your AC 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 accumulates inside the unit, it can create an environment that is conducive to the development of bacteria and fungus. This can cause a bad odor that is often described as smelling like dirty feet.

Another potential reason for an odor of stinky feet might be a dirty air filter. When the air filter becomes clogged with dirt, dust and other particles, it can cause low air quality and a musty smell that bears a resemblance to feet.

To solve this problem, 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 on a regular basis to ensure good air quality and restrict the growth of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your air conditioner stinks 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 extraordinarily 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, get everyone out of the building and call your gas company or emergency services right away.

Your AC Smells Like Mildew

If your air conditioner is giving off an odor like mildew, it could be due to a accumulation of moisture inside the unit. When moisture accumulates inside an air conditioner, it can promote 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. Once the air filter becomes clogged, it can result in poor air quality and a musty smell that is similar to mildew.

Regular air conditioning maintenance from Classic Air 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 undesirable scenarios is when the air coming out of your HVAC system smells like urine.

If your air conditioning equipment smells like urine, it could be traced back to a number of things. One possible 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 moist environment that can promote bacterial growth. The bacteria can emit a foul odor that some people describe as smelling like urine.

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

Your AC Smells Like Burning Plastic

If your air conditioner smells like burning plastic, this could indicate an electrical problem with the unit. After a while, the electrical components in the air conditioning system can wear out or malfunction, which can make a burning smell that resembles plastic.

Another possible reason for the smell could be a foreign object lodged in the unit. If something foreign gets trapped in the air conditioning system, it can get hot and result in a smell similar to burning plastic.

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

Your AC Smells Like Gas

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

As mentioned previously, a natural gas leak can be VERY dangerous 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 call your gas company or emergency services straight away.

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

Why My Air Conditioner Smells Like Vinegar

There could be several reasons a home's AC smells like vinegar. One possible cause might be a plugged air filter. One other potential cause of the smell may be a refrigerant leak. Sometimes after the refrigerant leaks, it can make a chemical odor that is similar to vinegar.

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

If you are looking to upgrade, Classic Air can help find the right unit to fit your home’s needs. We provide reliable, skilled air conditioner installation in Columbus.

Your AC Smells Like Chemicals

If the smell of chemicals is coming from your air conditioning unit, it could be caused by a refrigerant leak. In a situation where 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 reason for the smell could be problems with the electrical wiring or hardware inside the air conditioning system. This can produce a burning smell that is like chemicals or burning plastic.

If you think your system has a refrigerant leak or an electrical concern, it's important to shut down 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 protect against injury or damage to your house.

Weird Smells Coming from Your AC? Call the Pros at Classic Air

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