If Your Air Conditioner Smells, Here's How to Fix It

When your air conditioner starts putting out unusual or funky aromas, it is a good idea to take notice because it could be a sign of a major problem. Ignoring unpleasant smells coming from your cooling system may lead to serious damage to your HVAC system or even pose a risk to your health and safety.

Depending on the cause of the odor, 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 harmful problem, like a natural gas leak.

At Patterson & Stirling, we are experienced at getting to the root cause of stinky smells. If you smell something weird coming from your cooling system, you can bet that our team of skilled professionals has smelled it, too—and fixed it! We’ve earned our reputation as the go-to team for air conditioning repair in Erie.

What does a particular smell coming from your air conditioning mean? Here are several frequent air conditioner aromas and what they might mean:

Your AC Smells Like Feet

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

Another potential explanation for the stench of dirty feet may be a dirty air filter. When your HVAC system’s air filter becomes choked with dirt, dust and other particles, it can cause poor air quality and a musty smell that bears a resemblance to feet.

To fix 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 change the air filter routinely to promote good air quality and protect against the formation of bacteria and fungus.

Your AC Smells Like Rotten Eggs

If your air conditioner reeks of rotten eggs, it could 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 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.

My Air Conditioner Smells Like Mildew

If your cooling system is giving off an odor like mildew, it might be due to a collection of moisture inside the unit. When moisture forms inside an air conditioner, it can promote the growth of mold and mildew. This can cause a musty odor that bears a resemblance to mildew.

Another possible cause of the smell may be a soiled air filter. If the air filter becomes clogged, it can result in poor air quality and a musty smell that resembles mildew.

Annual air conditioning maintenance from Patterson & Stirling can help prevent both of these issues, because a good cleaning, inspection and filter change is a terrific way to keep your system operating at its best!

My Air Conditioner Smells Like Urine

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

If your air conditioning equipment reeks of urine, it could could be caused by multiple factors. One likely cause is a buildup of bacteria or mold in the your cooling system. This can happen when moisture accumulates in the system and creates a wet environment that is conducive to bacterial growth. The bacteria can create a foul odor that resembles urine.

Another possible cause of the smell 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 clogged with debris, it can cause water to back up and accumulate inside the unit. This can produce a musty smell that resembles urine.

Your AC Smells Like Burning Plastic

If your air conditioning system smells like burning plastic, it might be because of an electrical issue with the unit. Over time, the electrical parts in the air conditioning system can wear out or malfunction, 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 HVAC system. If something foreign gets stuck in the air conditioning system, it can get hot and result in a smell that reminds people of burning plastic.

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

Your AC Smells Like Gas

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

As mentioned previously, a natural gas leak can be VERY dangerous 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, evacuate the building and call your gas company or emergency services straight away.

Your AC Smells Like Fish

Should your air conditioner smell like fish, it could be due to a build-up of bacteria or mold in the unit. Moisture produces an environment that promotes the growth of bacteria and mold. This can cause a disgusting odor that can be described as smelling like fish or, as mentioned earlier, it also can create a smell like dirty feet.

Another plausible explanation for 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 fix the issue, it’s often necessary to have a professional check out and clean your HVAC system. They should be able to find the source of the smell and take the correct steps to remove any contaminants and prevent the problem from recurring.

Your AC Smells Like Vinegar

There could be multiple reasons your air conditioning system smells like vinegar. One possible cause is a dirty air filter. Another likely cause of the smell might be a refrigerant leak. If the refrigerant leaks, it can make a chemical odor that is similar to vinegar.

To fix the issue, it’s essential to have a skilled tech 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 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 planning to upgrade, Patterson & Stirling can help locate the correct unit to fit your home’s needs. We deliver reliable, professional air conditioner installation in Erie.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming out of your air conditioning unit, it could be the result of a refrigerant leak. When 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 source of the smell could be something wrong with the electrical wiring or parts inside the air conditioning system. This can cause a burning smell that is like chemicals or burning plastic.

If you think your system has a refrigerant leak or an electrical issue, it’s important to turn off your air conditioning system right away 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 residence.

Weird Smells Coming from the Air Conditioning? Call the Pros at Patterson & Stirling

If your air conditioner stinks and you aren’t able to fix it smoothly on your own, contact the cooling professionals at Patterson & Stirling. We have lots of experience working with a wide variety of cooling systems. Our crew has fixed many air conditioning troubles through the years—including weird smells. Call us today for quality AC repair in Erie!