When your air conditioner starts emitting odd or unappealing smells, it is a good idea to take notice because it could be a sign of a significant problem. Dismissing unpleasant smells coming from your air conditioner can lead to further damage to your AC or even pose a risk to your health and safety.

Depending on the smell, the root of the problem could 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 warning of a dangerous scenario, such as a natural gas leak.

At Alpine Summit Heating & Cooling, we are experienced at getting to the root cause of stinky smells. If you smell something odd coming from your air conditioner, you can bet that our team of talented professionals has smelled it, too—and fixed it! We’ve earned the reputation as the go-to team for air conditioning repair in Athol.

What does a particular smell coming out of your air conditioning mean? Here are a few frequent air conditioner aromas and what they could mean:

Your AC Smells Like Feet

If your air conditioner smells like feet, it may be because of a buildup of bacteria or fungus in the unit. When moisture accumulates inside the unit, it can create an environment that is favorable to the development of bacteria and fungus. This can result in a bad odor that is often described as smelling like dirty feet.

Another possible reason for an odor of stinky feet 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 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 change the air filter routinely to ensure good air quality and protect against the growth of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your air conditioner smells like rotten eggs, it might be because 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, which is added to it to make it easily detectable.

A natural gas leak can be 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.

My Air Conditioner Smells Like Mildew

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

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

Annual air conditioning maintenance from Alpine Summit Heating & Cooling can help protect against both of these problems, because a good cleaning, inspection and filter change is a terrific way to keep your system operating at its best!

My Air Conditioner Smells Like Urine

One of the most distressing 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 likely cause is a collection of bacteria or mold in the air conditioning system. This can happen in the event that moisture accumulates in the system and creates a wet environment that is conducive to bacterial growth. The bacteria can emit a foul odor that some people describe as smelling like urine.

Another feasible 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 clogged with 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.

Your AC Smells Like Burning Plastic

If your AC smells like burning plastic, this could indicate an electrical concern with the unit. Over time, the electrical components in the air conditioning system can wear out or bust, which can produce 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 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 AC unit, it’s essential to contact a professional right away.

My Air Conditioner Smells Like Gas

If your air conditioner smells like gas, it could be due to a natural gas leak in the unit or in your home. Natural gas has a distinct aroma, often described as smelling of rotten eggs or sulfur. That’s because a smell is put into natural gas to make it easily detectable.

As we said previously, 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 contact your gas company or emergency services straight away.

My Air Conditioner Smells Like Fish

If your air conditioning equipment smell like fish, you may have a situation where there's a build-up of bacteria or mold in the unit. Moisture creates an environment that fosters the growth of bacteria and mold. This can cause a foul 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 becomes trapped inside the unit and dies.

To correct the issue, it's worthwhile to have a professional inspect and clean your HVAC system. They can 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 AC smells like vinegar. One possible cause is a plugged air filter. One other possible cause of the smell could be a refrigerant leak. Sometimes after the refrigerant leaks, it can create a chemical odor that is similar to vinegar.

To fix the issue, it's beneficial to have a skilled specialist look at and clean your air conditioning.  If the odor continues after the cleaning and exchanging the air filter, it's best to reach back out to a professional to find and repair any hidden issues with your air conditioning. Or, they can tell you if your air conditioning ought to be replaced.

If you are planning to upgrade, Alpine Summit Heating & Cooling can help locate the right unit to fit your home’s needs. We deliver trustworthy, expert air conditioner installation in Athol.

The Air Conditioning Smells Like Chemicals

If the smell of chemicals is coming from your air conditioner, it could be due to a refrigerant leak. In a situation where the refrigerant leaks, it can create a chemical aroma that people sometimes describe as smelling like chemicals or paint thinner, vinegar or acetone.

An additional possible source of the smell could be an issue with the electrical wiring or hardware inside the air conditioning system. This can produce 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 shut down 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 avoid injury or damage to your home.

Weird Smells Coming from Your AC? Call the Pros at Alpine Summit Heating & Cooling

If your air conditioner smells nasty and you aren’t able to fix it easily on your own, call the cooling specialists at Alpine Summit Heating & Cooling. We have plenty of experience working with a wide variety of HVAC systems. Our crew has fixed countless air conditioning troubles throughout the years—including strange smells. Call us today for quality AC repair in Athol!