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

When your air conditioner starts emitting weird or gross aromas, it is important to take notice because it could be a sign of a significant problem. Ignoring unpleasant smells coming from your air conditioner could lead to further 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. Other times, it could also indicate something mechanically wrong with the AC. Some smells are a sign of a harmful situation, like a natural gas leak.

At Forster Heating, we are experienced at getting to the root cause of stinky smells. If you smell something weird coming from your AC, you can bet that our team of qualified specialists has smelled it, too—and fixed it! We’ve earned a reputation as the first call for air conditioning repair in Auburn.

What does a particular smell coming coming from your AC mean? Here are some typical air conditioner aromas and what they could mean:

The Air Conditioning 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 collects inside the unit, it can establish an environment that is conducive to the spread of bacteria and fungus. This can cause a nasty odor that is often described as smelling like feet.

Another likely reason for the smell could be a dirty air filter. When the air filter becomes filled with dirt, dust and other debris, it can result in substandard air quality and a musty smell that it similar to the smell of feet.

To solve this issue, 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 change the air filter regularly to ensure good air quality and protect against the development of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your air conditioning unit reeks of rotten eggs, it could be due to 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 added to it to make it easily detectable.

A natural gas leak is very 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.

The Air Conditioning Smells Like Mildew

If your cooling system emits a smell like mildew, it might be due to a buildup of moisture inside the unit. When moisture forms inside the air conditioning system, it can foster the growth of mold and mildew. This can cause a musty odor that bears a resemblance to mildew.

Another possible explanation for the smell might be a soiled air filter. When the air filter becomes clogged, it can cause poor air quality and a musty smell that resembles mildew.

Regular air conditioning maintenance from Forster Heating can help prevent both of these problems, because a good cleaning, inspection and filter change is a very good way to keep your system operating at its best!

Your AC Smells Like Urine

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

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

Another possible cause of the stink could be a clogged drain line. The condensation that forms inside the air conditioning unit needs to drain away effectively, but if the drain line becomes stopped up by debris, it can cause water to back up and collect inside the unit. This can produce a musty smell that can stink like urine.

Your AC Smells Like Burning Plastic

If your air conditioner smells like burning plastic, a possible cause could be an electrical concern with the unit. Over 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 lodged in the HVAC system. If something foreign gets trapped in the air conditioning system, it can become hot and emit a smell like burning plastic.

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

The Air Conditioning Smells Like Gas

If your AC smells like gas, it could be due to a natural gas leak in the unit or in the surrounding area. Natural gas has a recognizable odor, often described as smelling of rotten eggs or sulfur. That’s because an odor is put into natural gas to make sure that it is easily detectable.

As stated earlier, a natural gas leak can be VERY dangerous 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, get everyone out of the building and phone your gas company or emergency services right away.

The Air Conditioning Smells Like Fish

If your air conditioning equipment smell like fish, it could be due to a build-up of bacteria or mold in the unit. Moisture produces 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 create a smell like dirty feet.

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

To fix the issue, it’s often necessary to have a professional examine and clean your cooling system. They should be able to determine the source of the smell and take the proper steps to remove any contaminants and keep the problem from recurring.

My Air Conditioner Smells Like Vinegar

There could be multiple reasons your air conditioner smells like vinegar. One possible cause might be a plugged air filter. One other likely cause of the smell could be a refrigerant leak. When the refrigerant leaks, it can generate a chemical odor that is described as smelling of vinegar.

To fix the issue, it’s beneficial to have a skilled tech look at and clean your air conditioning.  If the odor continues 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 mechanic can tell you if your air conditioning needs to be replaced.

If you are planning to upgrade, Forster Heating can help find the ideal unit to fit your home’s needs. We offer trustworthy, professional air conditioner installation in Auburn.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming from your air conditioning equipment, it could be due to a refrigerant leak. In a situation where 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 reason for the smell could be problems with the electrical wiring or hardware inside the air conditioning system. This can result in a burning smell that is like chemicals or burning plastic.

If you think your system has a refrigerant leak or an electrical concern, it’s important to turn off 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 prevent injury or damage to your residence.

A Nasty Odor Coming from the Air Conditioning? Contact the Experts at Forster Heating

If your air conditioner smells nasty and you aren’t able to fix it simply on your own, call the cooling professionals at Forster Heating. We have plenty of experience working with a wide variety of HVAC systems. Our crew has fixed many air conditioning concerns through the years—including funky smells. Call us today for quality AC repair in Auburn!