When your air conditioner starts spewing odd or gross odors, it is a good idea to take notice because it could be a sign of a significant problem. Ignoring unpleasant smells coming from your air conditioner may lead to serious damage to your AC or even pose a risk to your health and safety.

Depending on the cause of the odor, the root of the problem may be bacteria or fungus in the system. On the other hand, it could also signal something mechanically wrong with the air conditioner. Some smells are a sign of a hazardous scenario, like a natural gas leak.

At Arizona Comfort Systems, we are experienced at getting to the root cause of stinky smells. If you smell something odd coming from your air conditioner, chances are our team of skilled specialists has smelled it, too—and fixed it! We’ve earned the reputation as the go-to team for air conditioning repair in Sierra Vista.

What does a certain smell billowing from your AC mean? Here are a few typical air conditioner odors and what they may mean:

The Air Conditioning Smells Like Feet

If your air conditioner smells like feet, it could be caused by 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 development of bacteria and fungus. This can produce a foul odor that is often described as smelling like dirty feet.

Another possible explanation for the smell could be a dirty air filter. If an air filter becomes clogged with dirt, dust and other contaminants, it can result in poor air quality and a musty smell that it similar to the smell of feet.

To fix 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 change the air filter on a regular basis to promote good air quality and prevent the formation of bacteria and fungus.

Your AC Smells Like Rotten Eggs

If your reeks of rotten eggs, it might be because of 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 is added to it to make it easily detectable.

A natural gas leak is a situation that 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 ventilate the area, get everyone out of the building and call your gas company or emergency services immediately.

Your AC Smells Like Mildew

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

Another possible reason for the smell might be a clogged 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.

Routine air conditioning maintenance from Arizona Comfort Systems can help avoid both of these issues, because a good cleaning, inspection and filter change is a very good way to keep your system running at its best!

Your AC Smells Like Urine

One of the most distressing situations is when the air coming out of your HVAC system smells like urine.

If your air conditioner reeks of urine, it could be traced back to a number of things. One likely cause is a collection of bacteria or mold in the your HVAC. This can happen if moisture accumulates in the system and creates a moist environment that favorable for bacterial growth. The bacteria can create a foul odor that is like urine.

Another feasible cause of the smell could be a blocked drain line. The condensation that forms inside the air conditioning unit needs to drain away correctly, but if the drain line becomes stopped up by debris, it can cause water to back up and accumulate inside the unit. This can produce a musty smell that is sometimes described as smelling of urine.

My Air Conditioner Smells Like Burning Plastic

If your air conditioner smells like burning plastic, a possible cause could be an electrical issue with the unit. After some time, the electrical components in the air conditioning system can wear out or malfunction, which can create a burning smell that resembles plastic.

Another possible cause of the smell could be a foreign object that somehow got in the HVAC system. If something foreign gets caught in the air conditioning system, it can get hot and result in a smell similar to burning plastic.

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

The Air Conditioning 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 recognizable odor, often described as smelling like rotten eggs or sulfur. That’s because this scent is put into natural gas to make sure that it is easily detectable.

As we said earlier, a natural gas leak can be VERY hazardous 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, evacuate the building and call your gas company or emergency services right away.

The Air Conditioning Smells Like Fish

Should your air conditioning equipment smell like fish, this could be a sign of a build-up of bacteria or mold in the unit. Moisture produces an environment that is conducive to the growth of bacteria and mold. This can cause a foul odor that can be 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 caught in 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 fix the issue, it's important to have a professional inspect and clean your HVAC system. They will be able to determine the source of the smell and take the appropriate steps to remove any contaminants and stop the problem from recurring.

Why My Air Conditioner Smells Like Vinegar

There could be several reasons an AC smells like vinegar. One possible cause is a dirty air filter. Another possible cause of the smell might 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 specialist examine and clean your air conditioning.  If the odor continues after the cleaning and changing of 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 mechanic can tell you if your air conditioning needs to be replaced.

If you are wanting to upgrade, Arizona Comfort Systems can help find the correct unit to fit your home’s needs. We deliver trustworthy, skilled air conditioner installation in Sierra Vista.

The Air Conditioning Smells Like Chemicals

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

An additional possible reason for the smell could be a problem with the electrical wiring or components inside the air conditioning system. This can result in 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 right away 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 home.

A Nasty Odor Coming from the Air Conditioning? Call the Pros at Arizona Comfort Systems

If your air conditioner stinks and you aren’t able to fix it easily on your own, call the cooling experts at Arizona Comfort Systems. We have plenty of experience working with a wide variety of AC systems. Our crew has fixed many air conditioning troubles over the years—including funky smells. Call us today for quality AC repair in Sierra Vista!