When your air conditioner starts putting out weird or funky odors, it is important to take notice because it could be a sign of a big problem. Ignoring unpleasant smells coming from your cooling system could lead to further 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. Other times, it could also sign something mechanically wrong with the air conditioning system. Some smells are a sign of a hazardous scenario, like a natural gas leak.

At Herman Allen Plumbing, Heating & Cooling, we have a nose for these sorts of things. If you smell something odd coming from your air conditioner, chances are our team of qualified professionals has smelled it, too—and fixed it! We’ve earned the reputation as the go-to team for air conditioning repair in Greater Richmond.

What does a certain smell billowing from your cooling system mean? Here are several frequent air conditioner odors and what they might mean:

My Air Conditioner Smells Like Feet

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

Another possible cause of the smell may be a dirty air filter. When the air filter becomes choked with dirt, dust and other contaminants, it can result in low air quality and a musty smell that resembles feet.

To solve this issue, 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 exchange the air filter on a regular basis to promote good air quality and prevent the development of bacteria and fungus.

My Air Conditioner Smells Like Rotten Eggs

If your air conditioning unit 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 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 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 air out the area, get everyone out of the building and call your gas company or emergency services at once.

My Air Conditioner Smells Like Mildew

If your AC emits a smell like mildew, it may be due to a accumulation 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 resembles mildew.

Another possible reason for the smell might be a soiled air filter. Once the air filter becomes clogged, it can lead to poor air quality and a musty smell that resembles mildew.

Annual air conditioning maintenance from Herman Allen Plumbing, Heating & Cooling 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!

My Air Conditioner Smells Like Urine

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

If your air conditioning stinks like urine, it could be traced back to a number of things. One possible cause is a buildup of bacteria or mold in the your cooling system. 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 some people describe as smelling like urine.

Another possible cause of the scent of urine 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 create a musty smell that resembles urine.

My Air Conditioner 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 break, which can produce a burning smell that resembles plastic.

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

If you think you smell burning plastic coming from your AC unit, it’s worthwhile to phone a professional right away.

My Air Conditioner Smells Like Gas

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

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

Why My Air Conditioner Smells Like Fish

If your AC smell like fish, it could be due to 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 strong odor that is sometimes described as smelling like fish or, as mentioned earlier, it also can result in a smell like dirty feet.

Another possible cause of the smell could be a dead animal or other biological material caught inside the air conditioning system. This often is possible if an animal such as a mouse or bird gets trapped inside the unit and dies.

To solve the issue, it's often necessary to have a professional check out and clean your HVAC system. They will be able to identify 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 an air conditioning system smells like vinegar. One possible cause is a clogged air filter. One other likely cause of the smell might be a refrigerant leak. When the refrigerant leaks, it can make a chemical odor that is described as smelling of vinegar.

To fix the issue, it's important to have a skilled specialist examine 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 find and repair any persistent issues with your air conditioning. Or, the mechanic can tell you if your air conditioning should be replaced.

If you are looking to upgrade, Herman Allen Plumbing, Heating & Cooling can help find the ideal unit to fit your home’s needs. We deliver reliable, skilled air conditioner installation in Greater Richmond.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is coming from your air conditioning unit, it could be the result of a refrigerant leak. If the refrigerant leaks, it can create a chemical aroma that is often described as smelling like chemicals or paint thinner, vinegar or acetone.

One other possible reason for the smell could be an issue with the electrical wiring or elements inside the air conditioning system. This can produce a burning smell that it similar to chemicals or burning plastic.

If you suspect a refrigerant leak or an electrical problem, 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 avoid injury or damage to your house.

Strange Smell Coming from Your AC? Call the Pros at Herman Allen Plumbing, Heating & Cooling

If your air conditioner stinks and you aren’t able to fix it easily on your own, call the cooling experts at Herman Allen Plumbing, Heating & Cooling. We have plenty of experience working with a wide variety of air conditioning systems. Our crew has fixed countless air conditioning problems throughout the years—including strange smells. Call us today for quality AC repair in Greater Richmond!