When your air conditioner starts putting out unusual or unappealing odors, it is necessary to take notice because it could be a sign of a big problem. Dismissing unpleasant smells coming from your air conditioning may lead to additional damage to your air conditioning or even pose a risk to your health and safety.

Depending on the cause of the odor, the cause may be bacteria or fungus in the system. In other cases, it could also sign something mechanically wrong with the air conditioning system. Some smells are a warning of a harmful scenario, such as a natural gas leak.

At 1st Choice Heating & Air Conditioning, we are skilled at diagnosing and fixing these type of problems. If you smell something weird coming from your cooling system, you can bet that our team of qualified pros has smelled it, too—and fixed it! We’ve earned the reputation as the first call for air conditioning repair in Mission Viejo.

What does a specific odor wafting from your AC mean? Here are several frequent air conditioner smells and what they might mean:

The Air Conditioning 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 collects inside the unit, it can create an environment that is conducive to the development of bacteria and fungus. This can produce a foul odor that is often described as smelling like feet.

Another likely reason for the smell may be a dirty air filter. If an air filter becomes filled with dirt, dust and other debris, it can cause substandard air quality and a musty smell that it similar to the smell of feet.

To solve this dilemma, 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 routinely to ensure good air quality and prevent the growth of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your stinks like rotten eggs, it may be the result of 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 extremely 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, evacuate the building and call your gas company or emergency services at once.

Your AC Smells Like Mildew

If your air conditioner emits a smell like mildew, it might 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 smell that bears a resemblance to mildew.

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

Regular air conditioning maintenance from 1st Choice Heating & Air Conditioning can help avoid both of these situations, because a good cleaning, inspection and filter change is a great way to keep your system working at its best!

Your AC Smells Like Urine

One of the most distressing situations is when your AC smells like urine.

If your air conditioning equipment reeks of urine, it could be due to a variety of factors. One possible cause is a accumulation of bacteria or mold in the air conditioning system. This can happen when moisture accumulates in the system and creates a wet environment that is conducive to bacterial growth. The bacteria can produce a foul odor that is like urine.

Another possible 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 choked with debris, it can cause water to back up and accumulate inside the unit. This can create a musty smell that is sometimes described as smelling of urine.

The Air Conditioning Smells Like Burning Plastic

If your air conditioning system smells like burning plastic, this could indicate an electrical concern with the unit. After a while, the electrical components in the air conditioning system can wear out or malfunction, which can create a burning smell that resembles plastic.

Another possible root cause of the smell could be a foreign object that somehow got in the the air conditioner. If something foreign gets trapped in the air conditioning system, it can heat up and emit a smell similar to burning plastic.

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

My Air Conditioner Smells Like Gas

If your air conditioner smells like gas, it could be because of a natural gas leak in the unit or in another part of your home. Natural gas has a recognizable aroma, often described as smelling similar to rotten eggs or sulfur. That’s because an odor is incorporated into natural gas so that it is easily detectable.

As stated previously, a natural gas leak can be VERY hazardous and calls for immediate attention. Should you suspect a gas leak, turn off your air conditioning system, open windows and doors to air out the home, leave the building and contact your gas company or emergency services straight away.

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

Another possible cause of the smell could be a dead animal or other biological material stuck inside the air conditioning system. This often is possible 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 examine and clean your cooling 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 numerous reasons your AC smells like vinegar. One possible cause might be a dirty air filter. A second possible cause of the smell could be a refrigerant leak. Sometimes after the refrigerant leaks, it can make a chemical odor that resembles vinegar.

To fix the issue, it's beneficial to have a skilled tech 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 underlying issues with your air conditioning. Or, the mechanic can tell you if your air conditioning ought to be replaced.

If you are planning to upgrade, 1st Choice Heating & Air Conditioning can help find the correct unit to fit your home’s needs. We deliver trustworthy, professional air conditioner installation in Mission Viejo.

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. In a situation where the refrigerant leaks, it can create a chemical odor that is often described 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 parts inside the air conditioning system. This can produce a burning smell that resembles chemicals or burning plastic.

If you think your system has a refrigerant leak or an electrical problem, it's important to shut off your air conditioning system immediately and contact a professional to inspect and repair the unit. Refrigerant leaks can be harmful and may require immediate attention to avoid injury or damage to your house.

Weird Smells Coming from the Air Conditioning? Contact the Experts at 1st Choice Heating & Air Conditioning

If your air conditioner reeks and you aren’t able to fix it easily on your own, contact the cooling professionals at 1st Choice Heating & Air Conditioning. We have lots of experience working with a wide variety of cooling systems. Our crew has fixed a multitude of air conditioning troubles through the years—including weird smells. Call us today for quality AC repair in Mission Viejo!