When your air conditioner starts spewing odd or unappealing odors, it is necessary to take notice because it could be a sign of a big problem. Disregarding unpleasant smells coming from your air conditioner can lead to serious 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. In other cases, it could also signal something mechanically wrong with the AC. Some smells are a warning of a hazardous problem, including a natural gas leak.

At AZ Air Conditioning and Heating, we have a nose for these sorts of things. If you smell something weird coming from your cooling system, you can bet that our team of qualified specialists has smelled it, too—and fixed it! We’ve earned our reputation as the premier company for air conditioning repair in Los Angeles.

What does a specific odor coming from your cooling system 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 may be because of a buildup of bacteria or fungus in the unit. When moisture collects inside the unit, it can establish an environment that is beneficial to the development of bacteria and fungus. This can cause a foul odor that is often described as smelling like feet.

Another potential reason for the stench of dirty feet could be a dirty air filter. When your HVAC system's air filter becomes filled with dirt, dust and other debris, 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 change the air filter on a regular basis to ensure good air quality and restrict the development of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your air conditioning equipment reeks of rotten eggs, it might be the result 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, which is because of a substance added to it to make it easily detectable.

A natural gas leak can be extremely 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, make everyone leave the building and call your gas company or emergency services at once.

My Air Conditioner Smells Like Mildew

If your air conditioner 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 resembles mildew.

Another possible reason for the smell might be a dirty air filter. When the air filter becomes clogged, it can cause poor air quality and a musty smell that is similar to mildew.

Annual air conditioning maintenance from AZ Air Conditioning and Heating can help avoid both of these issues, because a good cleaning, inspection and filter change is a great way to keep your system operating at its best!

Your AC Smells Like Urine

One of the most undesirable things is when an air conditioner smells like urine.

If your air conditioner stinks like urine, it could be due to a variety of 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 moist environment that is conducive to 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 filled with debris, it can cause water to back up and build up inside the unit. This can create a musty smell that resembles urine.

Your AC Smells Like Burning Plastic

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

Another possible root cause of the smell could be a foreign object lodged in the unit. If something foreign gets trapped in the air conditioning system, it can become hot and emit a smell that reminds people of burning plastic.

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

Your AC Smells Like Gas

If your air conditioning smells like gas, it could 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 of rotten eggs or sulfur. That’s because an odor is put into natural gas to make sure that it is easily detectable.

As mentioned previously, a natural gas leak can be VERY dangerous and calls for immediate attention. If 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 straight away.

My Air Conditioner Smells Like Fish

Should 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 causes an environment that fosters the growth of bacteria and mold. This can cause a strong odor that is sometimes described as smelling like fish or, as mentioned earlier, it also can cause a smell like dirty feet.

Another possible cause of the smell could be a dead animal or other biological material stuck within 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 solve the issue, it's worthwhile 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 prevent the problem from recurring.

Why 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 plugged air filter. Another potential cause of the smell may be a refrigerant leak. If the refrigerant leaks, it can make a chemical odor that is similar to vinegar.

To fix the issue, it's beneficial to have a skilled specialist inspect and clean your air conditioning.  If the odor persists after the cleaning and changing of the air filter, it's best to reach back out to a professional to diagnose 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 planning to upgrade, AZ Air Conditioning and Heating can help locate the ideal unit to fit your home’s needs. We deliver dependable, skilled air conditioner installation in Los Angeles.

Your AC Smells Like Chemicals

If the smell of chemicals is coming from your air conditioner, it could be caused by 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.

One other possible cause of the smell could be something wrong with the electrical wiring or elements inside the air conditioning system. This can produce a burning smell that resembles chemicals or burning plastic.

If you suspect 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 prevent injury or damage to your home.

A Nasty Odor Coming from Your Cooling? Contact the Experts at AZ Air Conditioning and Heating

If your air conditioner stinks and you aren’t able to fix it quickly on your own, call the cooling professionals at AZ Air Conditioning and Heating. We have lots of experience working with a wide variety of AC systems. Our crew has fixed countless air conditioning problems throughout the years—including strange smells. Call us today for quality AC repair in Los Angeles!