When your air conditioner starts emitting strange or funky aromas, it is important to take notice because it could be a sign of a major problem. Ignoring unpleasant smells coming from your air conditioning can 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 culprit may be bacteria or fungus in the system. On the other hand, it could also signal something mechanically wrong with the air conditioning system. Some smells are a sign of an unsafe scenario, like a natural gas leak.

At House of Heating Incorporated, we have a nose for these sorts of things. If you smell something weird coming from your AC, there's a good chance our team of qualified specialists has smelled it, too—and fixed it! We’ve earned a reputation as the go-to team for air conditioning repair in Marshfield.

What does a certain smell coming out of your AC mean? Here are a few frequent air conditioner odors and what they might mean:

My Air Conditioner 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 create an environment that is favorable to the growth of bacteria and fungus. This can cause a foul odor that is often described as smelling like stinky feet.

Another possible explanation for the stench of dirty feet could be a dirty air filter. If an air filter becomes choked with dirt, dust and other contaminants, it can lead to poor air quality and a musty smell that bears a resemblance to feet.

To fix this problem, it's important to have an experienced specialist 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 regularly to promote good air quality and restrict the formation of bacteria and fungus.

Your AC Smells Like Rotten Eggs

If your air conditioning equipment 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 air out the area, make everyone leave the building and call your gas company or emergency services at once.

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 foster the growth of mold and mildew. This can cause a musty stench that resembles mildew.

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

Annual air conditioning maintenance from House of Heating Incorporated can help protect against both of these problems, because a good cleaning, inspection and filter change is a very good way to keep your system working at its best!

My Air Conditioner Smells Like Urine

One of the most distressing scenarios is when an air conditioner smells like urine.

If your air conditioner smells like urine, it could be traced back to a number of things. One potential cause is a collection of bacteria or mold in the your cooling system. This can happen in the event that moisture accumulates in the system and creates a moist environment that is conducive to bacterial growth. The bacteria can emit a foul odor that resembles urine.

Another feasible cause of the smell could be a blocked drain line. The condensation that forms inside the air conditioning unit needs to drain away correctly, but if the drain line becomes filled with debris, it can cause water to back up and collect 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. Over time, the electrical parts in the air conditioning system can wear out or break, which can produce a burning smell that resembles plastic.

Another possible cause of the smell could be a foreign object lodged in the the air conditioner. If something foreign gets stuck in the air conditioning system, it can become hot and emit a smell similar to burning plastic.

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

The Air Conditioning Smells Like Gas

If your air conditioner smells like gas, there could be a natural gas leak in the unit or in your home. Natural gas has a recognizable odor, often described as smelling like rotten eggs or sulfur. That’s because a smell is incorporated into natural gas to make sure that it is easily detectable.

As we said earlier, a natural gas leak can be VERY harmful 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, leave the building and contact your gas company or emergency services as soon as possible.

Your AC Smells Like Fish

When 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 fosters the growth of bacteria and mold. This can cause a foul odor that is often described as smelling like fish or, as mentioned earlier, it also can create a smell like dirty feet.

Another potential 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 becomes trapped inside the unit and dies.

To correct the issue, it's often necessary to have a professional check out and clean your HVAC system. They should be able to determine the source of the smell and take the appropriate steps to remove any contaminants and stop the problem from recurring.

Why My Air Conditioner Smells Like Vinegar

There could be multiple reasons an air conditioner smells like vinegar. One possible cause is a dirty air filter. One other possible cause of the smell may be a refrigerant leak. Sometimes after the refrigerant leaks, it can make a chemical odor that resembles vinegar.

To fix the issue, it's beneficial to have a skilled specialist examine 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 diagnose and repair any hidden issues with your air conditioning. Or, the tech can tell you if your air conditioning should be replaced.

If you are planning to upgrade, House of Heating Incorporated can help select the right unit to fit your home’s needs. We provide dependable, professional air conditioner installation in Marshfield.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming from 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.

An additional possible cause 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 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 harmful and may require immediate attention to protect against injury or damage to your home.

Weird Smells Coming from Your AC? Contact the Experts at House of Heating Incorporated

If your air conditioner stinks and you aren’t able to fix it smoothly on your own, reach out to the cooling professionals at House of Heating Incorporated. We have lots of experience working with a wide variety of air conditioning systems. Our crew has fixed countless air conditioning problems throughout the years—including strange smells. Call us today for quality AC repair in Marshfield!