Why Your Air Conditioner Smells and How to Fix It

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

Depending on what you're smelling, the cause might be bacteria or fungus in the system. Other times, it could also signal something mechanically wrong with the AC. Some smells are a warning of a harmful problem, such as a natural gas leak.

At Booneville Heating & Cooling, we are experienced at getting to the root cause of stinky smells. If you smell something odd coming from your cooling system, chances are our team of qualified pros has smelled it, too—and fixed it! We’ve earned a reputation as the first call for air conditioning repair in Booneville.

What does a particular smell wafting coming from your air conditioning mean? Here are several frequent air conditioner smells and what they could mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it might be caused by a buildup of bacteria or fungus inside of it. When moisture builds inside the unit, it can establish an environment that is conducive to the growth of bacteria and fungus. This can produce a foul odor that is often described as smelling like feet.

Another potential reason for 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 result in poor air quality and a musty smell that bears a resemblance to feet.

To fix this problem, 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 routinely to provide good air quality and prevent the growth of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioner 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 distinct 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 ventilate the area, make everyone leave the building and call your gas company or emergency services right away.

Your AC Smells Like Mildew

If your air conditioner emits a smell like mildew, it might be due to a collection of moisture inside the unit. When moisture collects inside an air conditioner, it can cultivate the growth of mold and mildew. This can cause a musty stench that resembles mildew.

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

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

The Air Conditioning Smells Like Urine

One of the most unpleasant situations is when your AC smells like urine.

If your air conditioning smells like urine, it could could be caused by multiple factors. One possible 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 moist environment that favorable for bacterial growth. The bacteria can create a foul odor that it similar to urine.

Another feasible 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 filled with debris, it can cause water to back up and accumulate inside the unit. This can generate a musty smell that resembles urine.

Your AC Smells Like Burning Plastic

If your AC smells like burning plastic, this could indicate an electrical issue with the unit. After a while, the electrical parts in the air conditioning system can wear out or bust, which can produce a burning smell that resembles plastic.

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

If you think you smell burning plastic coming from your cooling system, it’s worthwhile to call a professional right away.

The Air Conditioning Smells Like Gas

If your air conditioning smells like gas, it could be because of a natural gas leak in the unit or in the surrounding area. Natural gas has a recognizable smell, often described as smelling similar to rotten eggs or sulfur. That’s because a smell is added to natural gas so that it is easily detectable.

As stated before, a natural gas leak can be VERY dangerous and requires immediate attention. If 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

When your air conditioning equipment smell like fish, this could be a sign of a build-up of bacteria or mold in the unit. Moisture produces an environment that promotes the growth of bacteria and mold. This can cause a strong 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 in the air conditioning system. This often is possible if an animal such as a mouse or bird gets trapped inside the unit and dies.

To correct the issue, it's important to have a professional check out and clean your HVAC system. They will be able to find the source of the smell and take the appropriate steps to remove any contaminants and prevent the problem from recurring.

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. One other possible cause of the smell may be a refrigerant leak. When the refrigerant leaks, it can make a chemical odor that is similar to vinegar.

To fix the issue, it's important to have a skilled mechanic examine and clean your air conditioning.  If the odor lingers after the cleaning and replacing 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, they can tell you if your air conditioning needs to be replaced.

If you are planning to upgrade, Booneville Heating & Cooling can help locate the correct unit to fit your home’s needs. We provide trustworthy, professional air conditioner installation in Booneville.

The Air Conditioning Smells Like Chemicals

If the smell of chemicals is coming out of your air conditioning unit, it could be due to a refrigerant leak. When the refrigerant leaks, it can create a chemical aroma that is often described as smelling like chemicals or paint thinner, vinegar or acetone.

Another possible cause of the smell could be problems with the electrical wiring or components inside the air conditioning system. This can result in a burning smell that it similar to 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 immediately 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 the Air Conditioning? Contact the Experts at Booneville Heating & Cooling

If your air conditioner smells nasty and you aren’t able to fix it easily on your own, contact the cooling specialists at Booneville Heating & Cooling. We have lots of experience working with a wide variety of HVAC 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 Booneville!