When your air conditioner starts putting out weird or funky smells, it is necessary to take notice because it could be a sign of a major problem. Disregarding unpleasant smells coming from your cooling system can lead to additional damage to your AC or even pose a risk to your health and safety.

Depending on the smell, the cause might be bacteria or fungus in the system. Other times, it could also indicate something mechanically wrong with the air conditioning system. Some smells are a sign of a harmful situation, including a natural gas leak.

At Patterson & Stirling, 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 professionals has smelled it, too—and fixed it! We’ve earned a reputation as the premier company for air conditioning repair in Erie.

What does a certain smell billowing out of your AC mean? Here are a few typical air conditioner odors and what they could mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it may be caused by a buildup of bacteria or fungus inside of it. When moisture builds inside the unit, it can create an environment that is beneficial to the growth of bacteria and fungus. This can result in a bad odor that is often described as smelling like dirty feet.

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

To correct this problem, it's important to have a quality service tech 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 restrict the development of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your reeks of rotten eggs, it might be caused by 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 allow gas to escape the area, get everyone out of the building and call your gas company or emergency services right away.

My Air Conditioner Smells Like Mildew

If your AC smells like mildew, it could be due to a collection of moisture inside the unit. When moisture forms inside a cooling system, it can foster the growth of mold and mildew. This can cause a musty odor that resembles mildew.

Another possible reason for 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 Patterson & Stirling can help prevent both of these situations, because a good cleaning, inspection and filter change is a great way to keep your system working at its best!

My Air Conditioner Smells Like Urine

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

If your air conditioning stinks like urine, it could could be caused by multiple factors. One potential cause is a collection of bacteria or mold in the your HVAC. 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 generate a musty smell that can stink like urine.

My Air Conditioner Smells Like Burning Plastic

If your air conditioning unit smells like burning plastic, this could indicate an electrical issue with the unit. After some time, the electrical parts in the air conditioning system can wear out or break, which can make a burning smell that resembles plastic.

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

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

My Air Conditioner Smells Like Gas

If your air conditioner smells like gas, it could be due to a natural gas leak in the unit or in your home. Natural gas has a distinctive smell, often described as smelling similar to rotten eggs or sulfur. That’s because this scent is added to natural gas so that it is easily detectable.

As we said previously, a natural gas leak can be VERY hazardous and needs immediate attention. Should you suspect a gas leak, turn off your air conditioning system, open windows and doors to air out the home, evacuate the building and phone your gas company or emergency services straight away.

Why My Air Conditioner Smells Like Fish

Should your air conditioning equipment smell like fish, you may have a situation where there's a build-up of bacteria or mold in the unit. Moisture causes an environment that promotes the growth of bacteria and mold. This can cause a strong odor that can be described as smelling like fish or, as mentioned earlier, it also can cause a smell like dirty feet.

Another potential cause of the smell could be a dead animal or other biological material stuck in 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 examine and clean your HVAC system. They will be able to determine the source of the smell and take the proper steps to remove any contaminants and stop the problem from recurring.

Why My Air Conditioner Smells Like Vinegar

There could be numerous reasons a home's air conditioner smells like vinegar. One possible cause might be a dirty air filter. A second likely cause of the smell could be a refrigerant leak. When the refrigerant leaks, it can make a chemical odor that resembles vinegar.

To fix the issue, it's essential to have a skilled specialist examine 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 hidden issues with your air conditioning. Or, the tech can tell you if your air conditioning ought to be replaced.

If you are planning to upgrade, Patterson & Stirling can help select the ideal unit to fit your home’s needs. We deliver reliable, expert air conditioner installation in Erie.

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. If the refrigerant leaks, it can create a chemical aroma that some people describe as smelling like chemicals or paint thinner, vinegar or acetone.

Another possible cause of the smell could be something wrong 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 believe there is a refrigerant leak or an electrical problem, it's important to shut down your air conditioning system as soon as possible and contact a professional to inspect and repair the unit. Refrigerant leaks can be dangerous and may require immediate attention to avoid injury or damage to your residence.

Strange Smell Coming from Your AC? Call the Pros at Patterson & Stirling

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