When your air conditioner starts spewing weird or unappealing aromas, it is important to take notice because it could be a sign of a major problem. Dismissing unpleasant smells coming from your air conditioning can lead to further damage to your air conditioning or even pose a risk to your health and safety.

Depending on the smell, the cause might be bacteria or fungus in the system. On the other hand, it could also signal something mechanically wrong with the air conditioning system. Some smells are a sign of a dangerous problem, such as a natural gas leak.

At Clean Air HVAC, we are experienced at getting to the root cause of stinky smells. If you smell something odd coming from your AC, there's a good chance 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 Pacheco.

What does a certain smell billowing out of your AC mean? Here are some common air conditioner smells and what they could mean:

The Air Conditioning Smells Like Feet

If your air conditioner smells like feet, it can be caused by a buildup of bacteria or fungus in the system. When moisture builds inside the unit, it can create an environment that is favorable to the development of bacteria and fungus. This can result in a foul odor that is often described as smelling like stinky feet.

Another potential cause of the smell might be a dirty air filter. When the air filter becomes filled with dirt, dust and other contaminants, it can lead to poor air quality and a musty smell that resembles feet.

To correct this dilemma, it's important to have a professional 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 provide good air quality and restrict the formation of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioner reeks of rotten eggs, it could be caused by 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 is a situation that is very 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.

The Air Conditioning Smells Like Mildew

If your air conditioner emits a smell like mildew, it could be due to a buildup of moisture inside the unit. When moisture accumulates inside an air conditioner, it can foster the growth of mold and mildew. This can cause a musty odor that it similar to mildew.

Another possible explanation for the smell could be a clogged air filter. Once the air filter becomes clogged, it can cause poor air quality and a musty smell that resembles mildew.

Annual air conditioning maintenance from Clean Air HVAC can help avoid both of these issues, because a good cleaning, inspection and filter change is a very good way to keep your system working at its best!

Your AC Smells Like Urine

One of the most unpleasant situations is when an air conditioner smells like urine.

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

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

The Air Conditioning Smells Like Burning Plastic

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

Another possible reason for the smell could be a foreign object that somehow got in the HVAC system. If something foreign gets trapped in the air conditioning system, it can heat up and cause a smell like burning plastic.

If you notice something that smells like burning plastic coming from your AC unit, it’s important to call a professional right away.

My Air Conditioner Smells Like Gas

If your air conditioning smells like gas, there could be a natural gas leak in the unit or in another part of your home. Natural gas has a distinctive aroma, often described as smelling like rotten eggs or sulfur. That’s because a smell is added to natural gas so that it is easily detectable.

As mentioned previously, a natural gas leak can be VERY harmful and requires immediate attention. When 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.

The Air Conditioning Smells Like Fish

When your air conditioner smell like fish, it could be due to a build-up of bacteria or mold in the unit. Moisture creates an environment that promotes 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 create a smell like dirty feet.

Another potential cause of the smell could be a dead animal or other biological material stuck 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 inspect and clean your cooling system. They can determine the source of the smell and take the proper steps to remove any contaminants and stop the problem from recurring.

The Air Conditioning Smells Like Vinegar

There could be multiple reasons an air conditioner smells like vinegar. One possible cause of the smell could be a dirty air filter. A second possible cause of the smell may be a refrigerant leak. Sometimes after the refrigerant leaks, it can make 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 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, the mechanic can tell you if your air conditioning should be replaced.

If you are wanting to upgrade, Clean Air HVAC can help select the right unit to fit your home’s needs. We provide dependable, expert air conditioner installation in Pacheco.

Your AC Smells Like Chemicals

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

An additional possible reason for the smell could be something wrong with the electrical wiring or components inside the air conditioning system. This can result in a burning smell that is like chemicals or burning plastic.

If you think your system has 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 harmful and may require immediate attention to prevent injury or damage to your house.

Strange Smell Coming from the Air Conditioning? Call the Pros at Clean Air HVAC

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