When your air conditioner starts spewing strange or unappealing aromas, it is important to take notice because it could be a sign of a big problem. Disregarding unpleasant smells coming from your air conditioning may lead to serious damage to your air conditioning or even pose a risk to your health and safety.

Depending on the smell, the culprit may be bacteria or fungus in the system. Other times, it could also signal something mechanically wrong with the air conditioning system. Some smells are even indicative of an unsafe problem, including a natural gas leak.

At Indoor Comfort Systems HVAC, we have a nose for these sorts of things. If you smell something weird coming from your AC, chances are our team of skilled pros has smelled it, too—and fixed it! We’ve earned our reputation as the first call for air conditioning repair in Croydon.

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

My Air Conditioner Smells Like Feet

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

Another potential explanation for the smell could be a dirty air filter. When your HVAC system's air filter becomes clogged with dirt, dust and other contaminants, it can cause substandard air quality and a musty smell that bears a resemblance to feet.

To solve this issue, 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 conditioning equipment 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 unique 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 extremely 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 may be due to a collection of moisture inside the unit. When moisture forms inside an air conditioner, it can cultivate the growth of mold and mildew. This can cause a musty stench that bears a resemblance to mildew.

Another possible cause of 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.

Annual air conditioning maintenance from Indoor Comfort Systems HVAC can help protect against both of these issues, 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 undesirable situations is when your AC smells like urine.

If your air conditioning equipment stinks like urine, it could could be caused by multiple factors. One potential cause is a buildup of bacteria or mold in the your HVAC. This can happen in the event that moisture accumulates in the system and creates a wet environment that favorable for bacterial growth. The bacteria can produce a foul odor that some people describe as smelling like urine.

Another feasible 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 stopped up by debris, it can cause water to back up and build up inside the unit. This can generate a musty smell that is sometimes described as smelling of urine.

My Air Conditioner Smells Like Burning Plastic

If your air conditioning system smells like burning plastic, a possible cause could be an electrical concern with the unit. After a while, the electrical components in the air conditioning system can wear out or break, which can produce a burning smell that resembles plastic.

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

If you notice something that smells like burning plastic coming from your air conditioner, it’s important to contact a professional right away.

My Air Conditioner Smells Like Gas

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

As stated 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, get everyone out of the building and call your gas company or emergency services right away.

Your AC Smells Like Fish

When your air conditioner smell like fish, you may have a situation where there's 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 strong odor that is often described as smelling like fish or, as mentioned earlier, it also can result in a smell like dirty feet.

Another plausible explanation for the smell could be a dead animal or other biological material stuck inside the air conditioning system. This often can happen if an animal such as a mouse or bird gets trapped inside the unit and dies.

To correct the issue, it's important to have a professional inspect and clean your cooling system. They will be able to determine the source of the smell and take the appropriate steps to remove any contaminants and prevent the problem from recurring.

My Air Conditioner Smells Like Vinegar

There could be multiple reasons your AC smells like vinegar. One possible cause of the smell could be a dirty air filter. Another likely cause of the smell may be a refrigerant leak. Sometimes after the refrigerant leaks, it can generate a chemical odor that resembles vinegar.

To fix the issue, it's beneficial to have a skilled mechanic inspect 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 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, Indoor Comfort Systems HVAC can help find the right unit to fit your home’s needs. We deliver trustworthy, professional air conditioner installation in Croydon.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is emitting out of your air conditioning equipment, it could be caused by a refrigerant leak. If the refrigerant leaks, it can create a chemical scent 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 parts 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 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 hazardous and may require immediate attention to avoid injury or damage to your house.

A Nasty Odor Coming from the Air Conditioning? Contact the Experts at Indoor Comfort Systems HVAC

If your air conditioner smells nasty and you aren’t able to fix it quickly on your own, reach out to the cooling specialists at Indoor Comfort Systems HVAC. We have years of experience working with a wide variety of air conditioning systems. Our crew has fixed countless air conditioning concerns throughout the years—including weird smells. Call us today for quality AC repair in Croydon!