When your air conditioner starts putting out strange or funky smells, it is important to take notice because it could be a sign of a big problem. Dismissing 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 what you're smelling, the root of the problem might be bacteria or fungus in the system. Other times, it could also sign something mechanically wrong with the air conditioning system. Some smells are a sign of a harmful problem, such as a natural gas leak.

At Morgner Inc. Air Conditioning & Heating, we have a nose for these sorts of things. If you smell something peculiar coming from your AC, there's a good chance our team of talented professionals has smelled it, too—and fixed it! We’ve earned our reputation as the go-to team for air conditioning repair in Saint Louis.

What does a certain smell wafting from your air conditioning mean? Here are several typical air conditioner smells and what they could mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it might be due to a buildup of bacteria or fungus in the unit. When moisture collects inside the unit, it can produce an environment that is beneficial to the growth of bacteria and fungus. This can result in a nasty odor that is often described as smelling like feet.

Another likely reason for an odor of stinky feet might be a dirty air filter. If an air filter becomes clogged with dirt, dust and other debris, it can cause low air quality and a musty smell that bears a resemblance to feet.

To solve 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 replace the air filter regularly to promote good air quality and protect against the formation of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioning unit stinks like rotten eggs, it might be caused by a natural gas leak in the unit or in the surrounding area. Natural gas has a distinctive 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 extremely dangerous and requires immediate attention. If you suspect a gas leak, turn off your air conditioning system, immediately open windows and doors to ventilate the area, evacuate the building and call your gas company or emergency services right away.

My Air Conditioner Smells Like Mildew

If your AC emits a smell like mildew, it may be due to a collection of moisture inside the unit. When moisture accumulates inside the air conditioning system, it can promote the growth of mold and mildew. This can cause a musty smell that bears a resemblance to mildew.

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

Regular air conditioning maintenance from Morgner Inc. Air Conditioning & Heating can help protect against both of these issues, because a good cleaning, inspection and filter change is a very good way to keep your system operating at its best!

My Air Conditioner Smells Like Urine

One of the most undesirable things is when an air conditioner smells like urine.

If your air conditioning smells like urine, it could be traced back to a number of things. One potential cause is a accumulation of bacteria or mold in the your cooling system. This can happen if moisture accumulates in the system and creates a damp environment that favorable for bacterial growth. The bacteria can emit a foul odor that is like urine.

Another possible cause of the stink could be a plugged drain line. The condensation that forms inside the air conditioning unit needs to drain away correctly, but if the drain line becomes choked with debris, it can cause water to back up and accumulate inside the unit. This can generate a musty smell that resembles urine.

My Air Conditioner Smells Like Burning Plastic

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

Another possible root cause of the smell could be a foreign object stuck in the unit. If something foreign gets stuck in the air conditioning system, it can become hot and cause a smell similar to burning plastic.

If you notice something that smells like burning plastic coming from your cooling system, it’s worthwhile to phone a professional right away.

My Air Conditioner Smells Like Gas

If your AC smells like gas, it could be because of a natural gas leak in the unit or in your home. Natural gas has a distinctive smell, often described as smelling like rotten eggs or sulfur. That’s because an odor is added to natural gas to make it easily detectable.

As mentioned previously, a natural gas leak can be VERY harmful and needs 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 as soon as possible.

Why My Air Conditioner Smells Like Fish

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

To correct the issue, it's important to have a professional examine and clean your cooling 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.

Why My Air Conditioner Smells Like Vinegar

There could be several reasons an air conditioner smells like vinegar. One possible cause might be a dirty air filter. Another possible cause of the smell may be a refrigerant leak. When the refrigerant leaks, it can generate a chemical odor that resembles vinegar.

To fix the issue, it's important to have a skilled mechanic inspect and clean your air conditioning.  If the odor lingers after the cleaning and changing of the air filter, it's best to reach back out to a professional to find and repair any underlying issues with your air conditioning. Or, they can tell you if your air conditioning ought to be replaced.

If you are wanting to upgrade, Morgner Inc. Air Conditioning & Heating can help locate the right unit to fit your home’s needs. We provide dependable, expert air conditioner installation in Saint Louis.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming out of your air conditioning equipment, it could be the result of a refrigerant leak. When the refrigerant leaks, it can create a chemical scent that people sometimes describe as smelling like chemicals or paint thinner, vinegar or acetone.

One other possible source of the smell could be a problem with the electrical wiring or parts inside the air conditioning system. This can cause a burning smell that it similar to chemicals or burning plastic.

If you suspect 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 harmful and may require immediate attention to avoid injury or damage to your house.

Strange Smell Coming from Your AC? Call the Pros at Morgner Inc. Air Conditioning & Heating

If your air conditioner reeks and you aren’t able to fix it smoothly on your own, call the cooling experts at Morgner Inc. Air Conditioning & Heating. We have lots of experience working with a wide variety of AC systems. Our crew has fixed a multitude of air conditioning concerns throughout the years—including strange smells. Call us today for quality AC repair in Saint Louis!