Why Your Air Conditioner Smells and How to Fix It

When your air conditioner starts putting out odd or gross smells, it is a good idea to take notice because it could be a sign of a significant problem. Ignoring unpleasant smells coming from your cooling system can lead to additional damage to your HVAC system or even pose a risk to your health and safety.

Depending on the cause of the odor, the cause could 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 sign of a dangerous scenario, like a natural gas leak.

At Kapaun & Brown, we have a nose for these sorts of things. If you smell something weird coming from your AC, you can bet that our team of skilled professionals has smelled it, too—and fixed it! We’ve earned a reputation as the first call for air conditioning repair in Marshalltown.

What does a particular smell wafting out of your cooling system mean? Here are some common air conditioner odors and what they may mean:

The Air Conditioning Smells Like Feet

If your air conditioner smells like feet, it could be due to a buildup of bacteria or fungus in the unit. When moisture collects inside the unit, it can establish an environment that is favorable to the spread of bacteria and fungus. This can produce a foul odor that is often described as smelling like stinky feet.

Another likely reason for the smell may be a dirty air filter. When the air filter becomes filled with dirt, dust and other particles, it can lead to substandard air quality and a musty smell that resembles feet.

To fix 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 routinely to ensure good air quality and prevent the formation of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

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

The Air Conditioning Smells Like Mildew

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

Another possible reason for the smell may be a clogged air filter. Once the air filter becomes clogged, it can lead to poor air quality and a musty smell that resembles mildew.

Annual air conditioning maintenance from Kapaun & Brown can help prevent both of these issues, because a good cleaning, inspection and filter change is a great way to keep your system operating at its best!

The Air Conditioning Smells Like Urine

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

If your air conditioning equipment stinks like urine, it could could be caused by multiple factors. One possible cause is a collection of bacteria or mold in the your HVAC. This can happen when moisture accumulates in the system and creates a damp environment that can promote bacterial growth. The bacteria can create a foul odor that is like urine.

Another potential cause of the scent of urine could be a clogged drain line. The condensation that forms inside the air conditioning unit needs to drain away properly, 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 generate a musty smell that is sometimes described as smelling of urine.

The Air Conditioning Smells Like Burning Plastic

If your air conditioning unit smells like burning plastic, this could indicate an electrical problem with the unit. After a while, the electrical elements in the air conditioning system can wear out or malfunction, which can produce 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 emit a smell similar to burning plastic.

If 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, there could be a natural gas leak in the unit or in the surrounding area. Natural gas has a distinctive aroma, often described as smelling similar to rotten eggs or sulfur. That’s because a smell is put into natural gas so that it is easily detectable.

As we said before, a natural gas leak can be VERY hazardous and calls for immediate attention. Should you suspect a gas leak, turn off your air conditioning system, open windows and doors to air out the home, get everyone out of the building and call your gas company or emergency services straight away.

Your AC Smells Like Fish

If your air conditioning equipment smell like fish, this could be a sign of a build-up of bacteria or mold in the unit. Moisture creates an environment that is conducive to the growth of bacteria and mold. This can cause a strong odor that is often described as smelling like fish or, as mentioned earlier, it also can create a smell like dirty feet.

Another plausible explanation for the smell could be a dead animal or other biological material trapped within the air conditioning system. This often can take place if an animal such as a mouse or bird gets trapped inside the unit and dies.

To solve the issue, it’s important to have a professional inspect and clean your air conditioning system. They will be able to determine 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 an air conditioning system smells like vinegar. One possible cause might be a clogged air filter. One other potential cause of the smell could be a refrigerant leak. When the refrigerant leaks, it can create a chemical odor that resembles vinegar.

To fix the issue, it’s important to have a skilled mechanic 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 identify and repair any hidden issues with your air conditioning. Or, the mechanic can tell you if your air conditioning ought to be replaced.

If you are wanting to upgrade, Kapaun & Brown can help select the correct unit to fit your home’s needs. We deliver trustworthy, expert air conditioner installation in Marshalltown.

The Air Conditioning Smells Like Chemicals

If the smell of chemicals is coming from your air conditioning unit, it could be due to a refrigerant leak. If the refrigerant leaks, it can create a chemical odor that people sometimes describe as smelling like chemicals or paint thinner, vinegar or acetone.

An additional possible reason for the smell could be a problem with the electrical wiring or components 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 concern, it’s important to shut off your air conditioning system as soon as possible and contact a professional to inspect and repair the unit. Refrigerant leaks can be harmful and may require immediate attention to avoid injury or damage to your home.

Weird Smells Coming from Your AC? Contact the Experts at Kapaun & Brown

If your air conditioner reeks and you aren’t able to fix it easily on your own, call the cooling professionals at Kapaun & Brown. We have years of experience working with a wide variety of air conditioning systems. Our crew has fixed a multitude of air conditioning troubles over the years—including strange smells. Call us today for quality AC repair in Marshalltown!