When your air conditioner starts spewing unusual or unappealing aromas, it is important to take notice because it could be a sign of a big problem. Dismissing unpleasant smells coming from your air conditioner could lead to further damage to your HVAC system or even pose a risk to your health and safety.

Depending on the cause of the odor, the culprit could be bacteria or fungus in the system. In other cases, it could also indicate something mechanically wrong with the air conditioner. Some smells are a sign of a harmful situation, such as a natural gas leak.

At H&C Heating and Cooling, we have a nose for these sorts of things. If you smell something weird coming from your AC, chances are our team of skilled specialists has smelled it, too—and fixed it! We’ve earned a reputation as the go-to team for air conditioning repair in Laurel.

What does a particular smell coming out of your AC mean? Here are a few 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 due to a buildup of bacteria or fungus inside of it. When moisture builds inside the unit, it can produce an environment that is favorable to the development of bacteria and fungus. This can cause a foul odor that is often described as smelling like feet.

Another possible reason for an odor of stinky feet could be a dirty air filter. When the air filter becomes choked with dirt, dust and other particles, it can cause poor air quality and a musty smell that resembles feet.

To fix this unpleasant situation, 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 replace the air filter routinely to promote good air quality and protect against the growth of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioner smells like rotten eggs, it might 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, that is added to it to make it easily detectable.

A natural gas leak is a situation that is 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, evacuate the building and call your gas company or emergency services right away.

My Air Conditioner Smells Like Mildew

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

Another possible explanation for the smell could be a soiled air filter. Once the air filter becomes clogged, it can cause poor air quality and a musty smell that is similar to mildew.

Routine air conditioning maintenance from H&C Heating and Cooling can help avoid both of these problems, because a good cleaning, inspection and filter change is a terrific way to keep your system running at its best!

My Air Conditioner 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 stinks like urine, it could could be caused by multiple factors. One likely cause is a buildup of bacteria or mold in the air conditioning system. This can happen when moisture accumulates in the system and creates a wet environment that can promote bacterial growth. The bacteria can create a foul odor that resembles 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 effectively, but if the drain line becomes clogged with debris, it can cause water to back up and build up inside the unit. This can produce a musty smell that is sometimes described as smelling of urine.

My Air Conditioner Smells Like Burning Plastic

If your AC smells like burning plastic, a possible cause could be an electrical issue with the unit. After a while, the electrical components in the air conditioning system can wear out or bust, which can produce 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 become hot and cause a smell that reminds people of burning plastic.

If you notice something that smells like burning plastic coming from your air conditioner, it’s worthwhile to call 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 odor, often described as smelling of rotten eggs or sulfur. That’s because this scent is added to natural gas to make sure that it is easily detectable.

As mentioned earlier, a natural gas leak can be VERY harmful 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, leave the building and phone your gas company or emergency services right away.

Why My Air Conditioner Smells Like Fish

If your AC 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 foul odor that can be described as smelling like fish or, as mentioned earlier, it also can cause a smell like dirty feet.

Another plausible explanation for the smell could be a dead animal or other biological material stuck inside 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 often necessary to have a professional check out and clean your cooling 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 AC smells like vinegar. One possible cause might be a plugged air filter. One other potential cause of the smell may be a refrigerant leak. If the refrigerant leaks, it can make a chemical odor that resembles vinegar.

To fix the issue, it's essential to have a skilled mechanic inspect 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 should be replaced.

If you are planning to upgrade, H&C Heating and Cooling can help find the right unit to fit your home’s needs. We offer dependable, expert air conditioner installation in Laurel.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming from your air conditioner, it could be caused by a refrigerant leak. When the refrigerant leaks, it can create a chemical scent that is often described as smelling like chemicals or paint thinner, vinegar or acetone.

An additional possible cause of the smell could be an issue with the electrical wiring or hardware inside the air conditioning system. This can result in a burning smell that resembles chemicals or burning plastic.

If you suspect a refrigerant leak or an electrical concern, 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 dangerous and may require immediate attention to protect against injury or damage to your residence.

Strange Smell Coming from Your AC? Call the Pros at H&C Heating and Cooling

If your air conditioner stinks and you aren’t able to fix it simply on your own, reach out to the cooling specialists at H&C Heating and Cooling. We have plenty of experience working with a wide variety of HVAC systems. Our crew has fixed a multitude of air conditioning troubles throughout the years—including funky smells. Call us today for quality AC repair in Laurel!