When your air conditioner starts putting out weird or gross odors, 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 conditioning can lead to additional damage to your air conditioning or even pose a risk to your health and safety.

Depending on the cause of the odor, the cause might be bacteria or fungus in the system. In other cases, it could also sign something mechanically wrong with the air conditioning system. Some smells are even indicative of a dangerous scenario, including a natural gas leak.

At Kapaun & Brown, 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 talented pros 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 specific odor coming out of your cooling system mean? Here are several typical air conditioner aromas and what they may mean:

The Air Conditioning Smells Like Feet

If your air conditioner smells like feet, it can be because of a buildup of bacteria or fungus in the system. 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 dirty feet.

Another possible reason for the stench of dirty feet could be a dirty air filter. If an air filter becomes choked with dirt, dust and other debris, it can cause poor air quality and a musty smell that it similar to the smell of feet.

To solve 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 change the air filter routinely to promote good air quality and restrict the formation of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your air conditioner 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 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 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 allow gas to escape the area, get everyone out of the building and call your gas company or emergency services at once.

My Air Conditioner Smells Like Mildew

If your AC emits a smell like mildew, it might be due to a accumulation of moisture inside the unit. When moisture collects inside the air conditioning system, it can cultivate the growth of mold and mildew. This can cause a musty odor that resembles mildew.

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

Regular air conditioning maintenance from Kapaun & Brown can help avoid 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 unpleasant situations is when the air coming out of your HVAC system smells like urine.

If your air conditioner reeks of urine, it could be due to a variety of factors. One likely cause is a buildup of bacteria or mold in the your HVAC. This can happen if moisture accumulates in the system and creates a wet environment that can promote bacterial growth. The bacteria can emit a foul odor that is like urine.

Another feasible 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 effectively, but if the drain line becomes stopped up by debris, it can cause water to back up and collect inside the unit. This can produce a musty smell that is sometimes described as smelling of urine.

Your AC Smells Like Burning Plastic

If your AC smells like burning plastic, this could indicate an electrical concern with the unit. Over time, the electrical parts 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 unit. If something foreign gets caught in the air conditioning system, it can heat up and emit a smell like burning plastic.

If you notice something that smells like burning plastic coming from your air conditioner, it’s worthwhile to phone a professional right away.

Your AC Smells Like Gas

If your air conditioning 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 odor, 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 stated earlier, a natural gas leak can be VERY dangerous and needs immediate attention. If you suspect a gas leak, turn off your air conditioning system, open windows and doors to air out the home, leave the building and phone your gas company or emergency services right away.

Why My Air Conditioner Smells Like Fish

Should your air conditioner smell like fish, this could be a sign of a build-up of bacteria or mold in the unit. Moisture causes an environment that is conducive to the growth of bacteria and mold. This can cause a disgusting odor that is sometimes described as smelling like fish or, as mentioned earlier, it also can cause a smell like dirty feet.

Another possible cause of the smell could be a dead animal or other biological material caught 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 worthwhile to have a professional check out and clean your cooling system. They should be able to identify the source of the smell and take the proper steps to remove any contaminants and stop the problem from recurring.

The Air Conditioning Smells Like Vinegar

There could be numerous reasons an air conditioner smells like vinegar. One possible cause might be a plugged air filter. A second potential cause of the smell may be a refrigerant leak. If the refrigerant leaks, it can create a chemical odor that resembles vinegar.

To fix the issue, it's essential to have a skilled tech examine 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 ought to be replaced.

If you are planning to upgrade, Kapaun & Brown can help find the correct unit to fit your home’s needs. We provide dependable, professional air conditioner installation in Marshalltown.

Your AC Smells Like Chemicals

If the smell of chemicals is coming out of your air conditioning unit, it could be the result of a refrigerant leak. In a situation where the refrigerant leaks, it can create a chemical odor that is often described as smelling like chemicals or paint thinner, vinegar or acetone.

An additional possible source of the smell could be a problem 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 think your system has a refrigerant leak or an electrical problem, 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 hazardous and may require immediate attention to avoid injury or damage to your home.

A Nasty Odor Coming from Your Cooling? Contact the Experts at Kapaun & Brown

If your air conditioner smells nasty and you aren’t able to fix it quickly on your own, contact the cooling experts at Kapaun & Brown. We have years of experience working with a wide variety of AC systems. Our crew has fixed many air conditioning problems throughout the years—including weird smells. Call us today for quality AC repair in Marshalltown!