When your air conditioner starts putting out strange or funky smells, it is a good idea to take notice because it could be a sign of a significant problem. Disregarding unpleasant smells coming from your cooling system can lead to serious damage to your air conditioning or even pose a risk to your health and safety.

Depending on what you're smelling, the cause may be bacteria or fungus in the system. On the other hand, it could also indicate something mechanically wrong with the air conditioning system. Some smells are a sign of a dangerous scenario, like a natural gas leak.

At McFadden Heating & Cooling, we are skilled at diagnosing and fixing these type of problems. If you smell something weird coming from your AC, you can bet that our team of talented pros has smelled it, too—and fixed it! We’ve earned the reputation as the go-to team for air conditioning repair in Dresden.

What does a particular smell wafting out of your cooling system mean? Here are several frequent air conditioner odors and what they might mean:

Your AC Smells Like Feet

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

Another potential cause of the stench of dirty feet might be a dirty air filter. When your HVAC system's air filter becomes filled with dirt, dust and other particles, it can result in substandard air quality and a musty smell that bears a resemblance to feet.

To fix this problem, 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 regularly to ensure good air quality and restrict the development of bacteria and fungus.

Your AC Smells Like Rotten Eggs

If your air conditioning equipment reeks of rotten eggs, it might be the result 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, that is 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 allow gas to escape the area, evacuate the building and call your gas company or emergency services immediately.

The Air Conditioning Smells Like Mildew

If your cooling system is giving off an odor like mildew, it may be due to a collection of moisture inside the unit. When moisture accumulates inside an air conditioner, it can cultivate the growth of mold and mildew. This can cause a musty stench that it similar to mildew.

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

Regular air conditioning maintenance from McFadden Heating & Cooling 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 unpleasant scenarios is when an air conditioner smells like urine.

If your air conditioner reeks of urine, it could could be caused by multiple factors. One possible cause is a accumulation of bacteria or mold in the air conditioning system. This can happen if moisture accumulates in the system and creates a wet environment that can promote bacterial growth. The bacteria can produce a foul odor that resembles 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 properly, but if the drain line becomes choked with debris, it can cause water to back up and collect inside the unit. This can generate a musty smell that is sometimes described as smelling of urine.

The Air Conditioning Smells Like Burning Plastic

If your air conditioning system 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 reason for the smell could be a foreign object stuck in the unit. If something foreign gets caught in the air conditioning system, it can become hot and cause a smell that reminds people of burning plastic.

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

The Air Conditioning Smells Like Gas

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

As we said earlier, a natural gas leak can be VERY hazardous and requires immediate attention. When 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

When your air conditioning equipment smell like fish, it could be due to 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 is often 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 trapped inside the air conditioning system. This often can take place if an animal such as a mouse or bird gets trapped inside the unit and dies.

To solve the issue, it's often necessary to have a professional examine and clean your air conditioning system. They will be able to find the source of the smell and take the correct steps to remove any contaminants and stop the problem from recurring.

Your AC Smells Like Vinegar

There could be several reasons an air conditioning system smells like vinegar. One possible cause is a clogged air filter. Another likely cause of the smell could be a refrigerant leak. When the refrigerant leaks, it can generate a chemical odor that resembles vinegar.

To fix the issue, it's beneficial to have a skilled tech inspect and clean your air conditioning.  If the odor persists after the cleaning and replacing of the air filter, it's best to reach back out to a professional to identify and repair any persistent issues with your air conditioning. Or, the mechanic can tell you if your air conditioning should be replaced.

If you are looking to upgrade, McFadden Heating & Cooling can help select the ideal unit to fit your home’s needs. We provide dependable, expert air conditioner installation in Dresden.

The Air Conditioning Smells Like Chemicals

If the smell of chemicals is coming from your air conditioning unit, it could be the result of a refrigerant leak. If the refrigerant leaks, it can create a chemical aroma that is often described as smelling like chemicals or paint thinner, vinegar or acetone.

One other possible cause of the smell could be problems with the electrical wiring or components inside the air conditioning system. This can cause a burning smell that resembles chemicals or burning plastic.

If you suspect a refrigerant leak or an electrical issue, 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 hazardous and may require immediate attention to protect against injury or damage to your residence.

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

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