The Sniff Test: Why Your Air Conditioner Smells and How to Fix It

When your air conditioner starts emitting odd or unappealing odors, it is a good idea to take notice because it could be a sign of a big problem. Dismissing 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 the cause of the odor, the cause may be bacteria or fungus in the system. In other cases, it could also signal something mechanically wrong with the air conditioning system. Some smells are even indicative of a dangerous scenario, including a natural gas leak.

At Ilten's, we are experienced at getting to the root cause of stinky smells. If you smell something weird coming from your air conditioner, there's a good chance our team of skilled pros has smelled it, too—and fixed it! We’ve earned our reputation as the premier company for air conditioning repair in Cedar Rapids.

What does a specific odor coming coming from your AC mean? Here are some frequent air conditioner smells and what they might mean:

My Air Conditioner Smells Like Feet

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

Another likely explanation for the smell might be a dirty air filter. If an air filter becomes choked with dirt, dust and other contaminants, it can result in low air quality and a musty smell that bears a resemblance to feet.

To correct 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 exchange the air filter on a regular basis to promote good air quality and protect against the development of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioner stinks like rotten eggs, it may be due to a natural gas leak in the unit or in the surrounding area. Natural gas has a distinct 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 very 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, get everyone out of the building and call your gas company or emergency services at once.

My Air Conditioner Smells Like Mildew

If your AC is giving off an odor like mildew, it may be due to a accumulation of moisture inside the unit. When moisture forms 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 reason for the smell could be a clogged air filter. If the air filter becomes clogged, it can result in poor air quality and a musty smell that has a resemblance to mildew.

Regular air conditioning maintenance from Ilten's can help protect against both of these problems, because a good cleaning, inspection and filter change is a great way to keep your system operating 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 conditioner reeks of urine, it could could be caused by multiple factors. One potential cause is a buildup of bacteria or mold in the air conditioning system. This can happen when moisture accumulates in the system and creates a moist environment that is conducive to bacterial growth. The bacteria can produce a foul odor that some people describe as smelling like urine.

Another possible cause of the scent of urine 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 filled with debris, it can cause water to back up and collect inside the unit. This can create 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 a while, the electrical components in the air conditioning system can wear out or break, which can create a burning smell that resembles plastic.

Another possible cause of the smell could be a foreign object stuck in the the air conditioner. If something foreign gets caught in the air conditioning system, it can heat up and emit 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 AC smells like gas, there could be 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. That’s because an odor is incorporated into natural gas to make sure that it is easily detectable.

As we said earlier, a natural gas leak can be VERY harmful 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 call your gas company or emergency services straight away.

Why My Air Conditioner 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 causes an environment that is conducive to the growth of bacteria and mold. This can cause a disgusting odor that is often described as smelling like fish or, as mentioned earlier, it also can cause a smell like dirty feet.

Another plausible explanation for the smell could be a dead animal or other biological material caught in the air conditioning system. This often is possible 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 can find the source of the smell and take the correct 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 AC smells like vinegar. One possible cause of the smell could be a clogged air filter. One other likely cause of the smell may be a refrigerant leak. If the refrigerant leaks, it can create a chemical odor that is described as smelling of vinegar.

To fix the issue, it's important to have a skilled specialist examine and clean your air conditioning.  If the odor persists after the cleaning and exchanging 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 needs to be replaced.

If you are looking to upgrade, Ilten's can help find the right unit to fit your home’s needs. We deliver reliable, expert air conditioner installation in Cedar Rapids.

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

An additional possible source of the smell could be something wrong with the electrical wiring or elements inside the air conditioning system. This can cause a burning smell that is like chemicals or burning plastic.

If you believe there is a refrigerant leak or an electrical concern, it's important to turn off 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 residence.

Strange Smell Coming from Your AC? Call the Pros at Ilten's

If your air conditioner stinks and you aren’t able to fix it easily on your own, reach out to the cooling specialists at Ilten's. We have plenty of experience working with a wide variety of air conditioning systems. Our crew has fixed a multitude of air conditioning problems through the years—including weird smells. Call us today for quality AC repair in Cedar Rapids!