When your air conditioner starts emitting odd or unappealing odors, it is important to take notice because it could be a sign of a major problem. Dismissing unpleasant smells coming from your cooling system 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 root of the problem might be bacteria or fungus in the system. Other times, it could also signal something mechanically wrong with the air conditioning system. Some smells are a sign of an unsafe scenario, including a natural gas leak.

At Temperature Doctors Heating & Cooling, we are skilled at diagnosing and fixing these type of problems. If you smell something odd coming from your air conditioner, you can bet that our team of skilled specialists has smelled it, too—and fixed it! We’ve earned the reputation as the first call for air conditioning repair in Rockford.

What does a specific odor billowing from your cooling system mean? Here are a few common air conditioner smells and what they could mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it could be because of a buildup of bacteria or fungus in the unit. When moisture builds inside the unit, it can establish an environment that is favorable to the spread of bacteria and fungus. This can result in a bad odor that is often described as smelling like feet.

Another potential explanation for the stench of dirty feet may be a dirty air filter. When the air filter becomes filled with dirt, dust and other contaminants, it can result in poor air quality and a musty smell that it similar to the smell of feet.

To solve this dilemma, 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 ensure good air quality and restrict the formation of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioning unit stinks like 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 extremely 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, get everyone out of the building and call your gas company or emergency services immediately.

My Air Conditioner Smells Like Mildew

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

Another possible explanation for the smell could be a soiled air filter. If the air filter becomes clogged, it can lead to poor air quality and a musty smell that resembles mildew.

Regular air conditioning maintenance from Temperature Doctors Heating & Cooling can help avoid both of these situations, 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 situations is when an air conditioner smells like urine.

If your air conditioning reeks of urine, it could be due to a variety of factors. One potential cause is a buildup of bacteria or mold in the air conditioning system. This can happen if moisture accumulates in the system and creates a moist environment that is conducive to bacterial growth. The bacteria can produce a foul odor that is like urine.

Another potential cause of the stink could be a clogged 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 collect inside the unit. This can create a musty smell that resembles urine.

My Air Conditioner Smells Like Burning Plastic

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

Another possible reason for the smell could be a foreign object lodged in the HVAC system. If something foreign gets caught in the air conditioning system, it can get hot and result in a smell similar to burning plastic.

If you think you smell burning plastic coming from your air conditioner, it’s essential to phone 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 your home. Natural gas has a recognizable odor, often described as smelling like rotten eggs or sulfur. That’s because a smell is put into natural gas so that it is easily detectable.

As mentioned before, a natural gas leak can be VERY hazardous 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, get everyone out of the building and contact your gas company or emergency services straight away.

Why My Air Conditioner Smells Like Fish

If your air conditioning equipment 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 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 caught within 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 solve the issue, it's important to have a professional check out and clean your air conditioning system. They can determine the source of the smell and take the appropriate steps to remove any contaminants and prevent the problem from recurring.

Why My Air Conditioner Smells Like Vinegar

There could be numerous reasons your AC smells like vinegar. One possible cause is a clogged air filter. A second possible cause of the smell could be a refrigerant leak. Sometimes after the refrigerant leaks, it can create a chemical odor that is similar to vinegar.

To fix the issue, it's essential to have a skilled specialist look at 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 find and repair any persistent issues with your air conditioning. Or, the tech can tell you if your air conditioning needs to be replaced.

If you are planning to upgrade, Temperature Doctors Heating & Cooling can help select the correct unit to fit your home’s needs. We deliver trustworthy, expert air conditioner installation in Rockford.

My Air Conditioner Smells Like Chemicals

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

An additional possible source of the smell could be an issue with the electrical wiring or elements inside the air conditioning system. This can produce a burning smell that it similar to chemicals or burning plastic.

If you believe there is a refrigerant leak or an electrical concern, it's important to shut down 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.

Strange Smell Coming from Your AC? Call the Pros at Temperature Doctors Heating & Cooling

If your air conditioner stinks and you aren’t able to fix it smoothly on your own, call the cooling specialists at Temperature Doctors Heating & Cooling. We have years of experience working with a wide variety of AC systems. Our crew has fixed countless air conditioning concerns over the years—including weird smells. Call us today for quality AC repair in Rockford!