The Sniff Test: Why Your Air Conditioner Smells and How to Fix It

When your air conditioner starts spewing strange or funky smells, it is important to take notice because it could be a sign of a significant problem. Disregarding unpleasant smells coming from your air conditioning may lead to serious damage to your air conditioning or even pose a risk to your health and safety.

Depending on the smell, the cause may be bacteria or fungus in the system. Other times, it could also indicate something mechanically wrong with the air conditioning system. Some smells are a warning of a dangerous problem, including a natural gas leak.

At Northwest Services, we are experienced at getting to the root cause of stinky smells. If you smell something weird coming from your air conditioner, chances are our team of skilled specialists has smelled it, too—and fixed it! We’ve earned the reputation as the go-to team for air conditioning repair in Swanton.

What does a certain smell coming coming from your AC mean? Here are some frequent air conditioner aromas and what they could mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it might be due to a buildup of bacteria or fungus inside of it. When moisture accumulates inside the unit, it can establish an environment that is favorable to the development of bacteria and fungus. This can produce a bad odor that is often described as smelling like dirty feet.

Another possible cause of an odor of stinky feet might be a dirty air filter. When the air filter becomes filled with dirt, dust and other contaminants, it can lead to poor air quality and a musty smell that resembles feet.

To fix this issue, 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 exchange the air filter regularly to ensure good air quality and prevent the development of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioning equipment reeks of 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 because of a substance 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 allow gas to escape 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 emits a smell like mildew, it could be due to a buildup of moisture inside the unit. When moisture forms inside a cooling system, it can promote the growth of mold and mildew. This can cause a musty stench that it similar to mildew.

Another possible cause of the smell could be a clogged air filter. Once the air filter becomes clogged, it can cause poor air quality and a musty smell that has a resemblance to mildew.

Regular air conditioning maintenance from Northwest Services can help prevent both of these problems, because a good cleaning, inspection and filter change is a terrific way to keep your system working at its best!

My Air Conditioner Smells Like Urine

One of the most undesirable situations is when your AC 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 buildup of bacteria or mold in the your HVAC. This can happen in the event that moisture accumulates in the system and creates a moist environment that is conducive to bacterial growth. The bacteria can produce a foul odor that some people describe as smelling like 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 choked with debris, it can cause water to back up and build up inside the unit. This can generate a musty smell that resembles urine.

My Air Conditioner Smells Like Burning Plastic

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

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

If you think 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 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 recognizable smell, often described as smelling of rotten eggs or sulfur. That’s because an odor is put into natural gas to make it easily detectable.

As stated previously, 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 straight 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 creates an environment that fosters the growth of bacteria and mold. This can cause a foul odor that is sometimes described as smelling like fish or, as mentioned earlier, it also can result in a smell like dirty feet.

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

To correct the issue, it's often necessary to have a professional check out and clean your HVAC system. They should be able to determine 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 multiple reasons your air conditioner smells like vinegar. One possible cause might be a clogged air filter. Another possible 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 beneficial to have a skilled tech inspect and clean your air conditioning.  If the odor lingers after the cleaning and exchanging the air filter, it's best to reach back out to a professional to diagnose and repair any underlying issues with your air conditioning. Or, they can tell you if your air conditioning ought to be replaced.

If you are looking to upgrade, Northwest Services can help select the ideal unit to fit your home’s needs. We provide reliable, skilled air conditioner installation in Swanton.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming from your air conditioning equipment, it could be caused by a refrigerant leak. When the refrigerant leaks, it can create a chemical aroma that some people 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 parts inside the air conditioning system. This can cause a burning smell that resembles chemicals or burning plastic.

If you suspect 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 hazardous and may require immediate attention to prevent injury or damage to your home.

Strange Smell Coming from Your AC? Call the Pros at Northwest Services

If your air conditioner reeks and you aren’t able to fix it quickly on your own, contact the cooling specialists at Northwest Services. We have lots of experience working with a wide variety of cooling systems. Our crew has fixed a multitude of air conditioning troubles throughout the years—including strange smells. Call us today for quality AC repair in Swanton!