When your air conditioner starts emitting unusual or unappealing odors, it is necessary to take notice because it could be a sign of a major problem. Disregarding unpleasant smells coming from your air conditioning can lead to serious damage to your HVAC system or even pose a risk to your health and safety.

Depending on the smell, the cause could be bacteria or fungus in the system. On the other hand, it could also sign something mechanically wrong with the AC. Some smells are a sign of a harmful scenario, like a natural gas leak.

At May's Heating & Air, we are skilled at diagnosing and fixing these type of problems. If you smell something peculiar coming from your cooling system, you can bet that our team of skilled specialists has smelled it, too—and fixed it! We’ve earned our reputation as the go-to team for air conditioning repair in Frederick.

What does a certain smell billowing from your air conditioning mean? Here are some common air conditioner aromas and what they might mean:

My Air Conditioner 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 accumulates inside the unit, it can produce an environment that is beneficial to the growth of bacteria and fungus. This can result in a bad odor that is often described as smelling like stinky feet.

Another possible explanation for an odor of stinky feet might be a dirty air filter. If an air filter becomes choked with dirt, dust and other particles, it can lead to poor air quality and a musty smell that resembles feet.

To solve this dilemma, 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 on a regular basis to provide good air quality and prevent the formation of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your stinks like rotten eggs, it could be caused by 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 ventilate 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 air conditioner smells like mildew, it might be due to a collection of moisture inside the unit. When moisture collects inside an air conditioner, it can foster the growth of mold and mildew. This can cause a musty stench that bears a resemblance to mildew.

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

Annual air conditioning maintenance from May's Heating & Air can help protect against both of these issues, because a good cleaning, inspection and filter change is a terrific way to keep your system operating at its best!

My Air Conditioner Smells Like Urine

One of the most unpleasant things is when an air conditioner smells like urine.

If your air conditioner stinks 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 wet environment that is conducive to bacterial growth. The bacteria can emit a foul odor that it similar to urine.

Another potential cause of the smell could be a plugged drain line. The condensation that forms inside the air conditioning unit needs to drain away correctly, 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 can stink like urine.

My Air Conditioner Smells Like Burning Plastic

If your air conditioning unit smells like burning plastic, it might be because of an electrical problem with the unit. Over time, 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 stuck 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 think you smell burning plastic coming from your AC unit, it’s important to call a professional right away.

My Air Conditioner Smells Like Gas

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

As stated earlier, a natural gas leak can be VERY harmful and calls for immediate attention. When 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 straight away.

My Air Conditioner Smells Like Fish

If 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 is conducive to the growth of bacteria and mold. This can cause a foul odor that can be described as smelling like fish or, as mentioned earlier, it also can result in a smell like dirty feet.

Another potential cause of the smell could be a dead animal or other biological material trapped in 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 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 appropriate steps to remove any contaminants and prevent the problem from recurring.

The Air Conditioning Smells Like Vinegar

There could be several reasons your air conditioning system smells like vinegar. One possible cause is a clogged air filter. A second potential cause of the smell might be a refrigerant leak. If the refrigerant leaks, it can generate a chemical odor that is described as smelling of vinegar.

To fix the issue, it’s beneficial to have a skilled mechanic inspect 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 find and repair any hidden issues with your air conditioning. Or, the tech can tell you if your air conditioning needs to be replaced.

If you are wanting to upgrade, May's Heating & Air can help select the right unit to fit your home’s needs. We deliver dependable, professional air conditioner installation in Frederick.

Your AC Smells Like Chemicals

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

Another possible reason for the smell could be something wrong with the electrical wiring or hardware inside the air conditioning system. This can produce a burning smell that it similar to chemicals or burning plastic.

If you suspect a refrigerant leak or an electrical problem, it’s important to turn off your air conditioning system right away 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 residence.

A Nasty Odor Coming from Your Cooling? Call the Pros at May's Heating & Air

If your air conditioner stinks and you aren’t able to fix it easily on your own, contact the cooling experts at May's Heating & Air. We have lots of experience working with a wide variety of HVAC systems. Our crew has fixed a multitude of air conditioning problems throughout the years—including strange smells. Call us today for quality AC repair in Frederick!