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

Depending on what you're smelling, the culprit could be bacteria or fungus in the system. On the other hand, it could also signal something mechanically wrong with the AC. Some smells are even indicative of an unsafe situation, like a natural gas leak.

At Controlled Comfort HVAC, we have a nose for these sorts of things. If you smell something weird coming from your cooling system, chances are our team of talented professionals has smelled it, too—and fixed it! We’ve earned a reputation as the first call for air conditioning repair in Carpentersville.

What does a specific odor billowing from your air conditioning mean? Here are some typical air conditioner odors and what they may mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it may be because of a buildup of bacteria or fungus in the system. 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 nasty odor that is often described as smelling like stinky feet.

Another possible cause of an odor of stinky feet may be a dirty air filter. When the air filter becomes filled with dirt, dust and other contaminants, it can lead to low air quality and a musty smell that bears a resemblance to feet.

To correct this unpleasant situation, 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 exchange the air filter routinely to promote good air quality and restrict the formation of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioning unit smells like rotten eggs, it may be the result of a natural gas leak in the unit or in the surrounding area. Natural gas has a distinctive 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 a situation that is extremely 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, get everyone out of the building and call your gas company or emergency services at once.

My Air Conditioner Smells Like Mildew

If your AC smells like mildew, it could be due to a accumulation of moisture inside the unit. When moisture collects inside the air conditioning system, 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 soiled air filter. When the air filter becomes clogged, it can result in poor air quality and a musty smell that is similar to mildew.

Regular air conditioning maintenance from Controlled Comfort HVAC can help prevent both of these situations, because a good cleaning, inspection and filter change is a terrific way to keep your system working at its best!

My Air Conditioner Smells Like Urine

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

If your air conditioner reeks of urine, it could be traced back to a number of things. One possible cause is a accumulation of bacteria or mold in the air conditioning system. This can happen in the event that moisture accumulates in the system and creates a moist environment that can promote bacterial growth. The bacteria can create a foul odor that resembles urine.

Another potential cause of the stink could be a blocked drain line. The condensation that forms inside the air conditioning unit needs to drain away properly, but if the drain line becomes stopped up by debris, it can cause water to back up and accumulate inside the unit. This can generate a musty smell that resembles urine.

My Air Conditioner Smells Like Burning Plastic

If your air conditioning unit smells like burning plastic, a possible cause could be an electrical problem with the unit. Over time, the electrical elements in the air conditioning system can wear out or bust, which can make a burning smell that resembles plastic.

Another possible reason for the smell could be a foreign object that somehow got in the unit. If something foreign gets caught in the air conditioning system, it can become hot and cause a smell like burning plastic.

If you smell burning plastic coming from your AC unit, it’s essential to phone a professional right away.

My Air Conditioner Smells Like Gas

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

As we said previously, a natural gas leak can be VERY hazardous and calls for 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 contact your gas company or emergency services straight away.

Why My Air Conditioner 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 disgusting odor that is sometimes described as smelling like fish or, as mentioned earlier, it also can result in a smell like dirty feet.

Another possible cause of the smell could be a dead animal or other biological material trapped within the air conditioning system. This often can take place if an animal such as a mouse or bird becomes trapped inside the unit and dies.

To correct the issue, it's important to have a professional inspect and clean your air conditioning system. They will be able to identify 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 multiple reasons an air conditioning system smells like vinegar. One possible cause might be a plugged air filter. Another potential cause of the smell may be a refrigerant leak. If the refrigerant leaks, it can generate a chemical odor that resembles vinegar.

To fix the issue, it's important to have a skilled tech inspect 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 diagnose and repair any underlying issues with your air conditioning. Or, the tech can tell you if your air conditioning ought to be replaced.

If you are wanting to upgrade, Controlled Comfort HVAC can help locate the correct unit to fit your home’s needs. We provide dependable, professional air conditioner installation in Carpentersville.

Your AC Smells Like Chemicals

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

Another possible source of the smell could be something wrong with the electrical wiring or elements inside the air conditioning system. This can result in 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 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 home.

Weird Smells Coming from Your Cooling? Contact the Experts at Controlled Comfort HVAC

If your air conditioner smells nasty and you aren’t able to fix it quickly on your own, reach out to the cooling professionals at Controlled Comfort HVAC. We have plenty of experience working with a wide variety of HVAC systems. Our crew has fixed a multitude of air conditioning problems over the years—including funky smells. Call us today for quality AC repair in Carpentersville!