When your air conditioner starts putting out unusual or unappealing odors, it is necessary to take notice because it could be a sign of a big problem. Dismissing unpleasant smells coming from your air conditioner may lead to additional damage to your HVAC system 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. In other cases, it could also indicate something mechanically wrong with the air conditioning system. Some smells are a warning of a dangerous situation, including a natural gas leak.

At 1st Choice Heating & Air Conditioning, we are experienced at getting to the root cause of stinky smells. If you smell something peculiar coming from your air conditioner, there's a good chance 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 Lake Forest.

What does a certain smell wafting from your AC mean? Here are a few typical air conditioner smells and what they might mean:

Your AC Smells Like Feet

If your air conditioner smells like feet, it can be due to a buildup of bacteria or fungus in the system. When moisture collects inside the unit, it can produce an environment that is conducive to the development of bacteria and fungus. This can cause a bad odor that is often described as smelling like feet.

Another likely reason for an odor of stinky feet could be a dirty air filter. If an air filter becomes clogged with dirt, dust and other contaminants, it can lead to substandard air quality and a musty smell that bears a resemblance to feet.

To fix this issue, 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 routinely to ensure good air quality and prevent the development of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your smells like rotten eggs, it might be because of 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 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, evacuate 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 buildup of moisture inside the unit. When moisture accumulates inside an air conditioner, it can foster the growth of mold and mildew. This can cause a musty stench that resembles mildew.

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

Annual air conditioning maintenance from 1st Choice Heating & Air Conditioning 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!

Your AC Smells Like Urine

One of the most undesirable things is when your AC smells like urine.

If your air conditioning equipment stinks like urine, it could could be caused by multiple factors. One possible cause is a accumulation of bacteria or mold in the your HVAC. This can happen when moisture accumulates in the system and creates a damp environment that can promote bacterial growth. The bacteria can create a foul odor that some people describe as smelling like urine.

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

Your AC 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 components in the air conditioning system can wear out or bust, which can make a burning smell that resembles plastic.

Another possible cause of the smell could be a foreign object that somehow got in the unit. If something foreign gets stuck in the air conditioning system, it can get hot and cause a smell similar to burning plastic.

If you think you smell burning plastic coming from your air conditioner, it’s important to call a professional right away.

My Air Conditioner Smells Like Gas

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

As mentioned previously, a natural gas leak can be VERY harmful and requires immediate attention. When you suspect a gas leak, turn off your air conditioning system, open windows and doors to air out the home, evacuate the building and contact your gas company or emergency services as soon as possible.

Your AC 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 creates an environment that fosters 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 trapped in the air conditioning system. This often can happen if an animal such as a mouse or bird becomes trapped inside the unit and dies.

To correct the issue, it's worthwhile to have a professional inspect and clean your cooling system. They will be able to find 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 your air conditioner smells like vinegar. One possible cause might be a plugged air filter. One other potential 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 beneficial to have a skilled specialist inspect and clean your air conditioning.  If the odor persists after the cleaning and changing of the air filter, it's best to reach back out to a professional to identify and repair any underlying issues with your air conditioning. Or, the mechanic can tell you if your air conditioning should be replaced.

If you are planning to upgrade, 1st Choice Heating & Air Conditioning can help select the ideal unit to fit your home’s needs. We offer dependable, professional air conditioner installation in Lake Forest.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming out of your air conditioning equipment, it could be due to a refrigerant leak. In a situation where the refrigerant leaks, it can create a chemical odor that people sometimes describe as smelling like chemicals or paint thinner, vinegar or acetone.

One other possible reason for the smell could be a problem with the electrical wiring or components inside the air conditioning system. This can produce a burning smell that is like chemicals or burning plastic.

If you believe there is 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 harmful and may require immediate attention to avoid injury or damage to your home.

A Nasty Odor Coming from Your AC? Contact the Experts at 1st Choice Heating & Air Conditioning

If your air conditioner reeks and you aren’t able to fix it simply on your own, contact the cooling experts at 1st Choice Heating & Air Conditioning. We have plenty of experience working with a wide variety of air conditioning 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 Lake Forest!