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

Depending on the smell, the culprit could be bacteria or fungus in the system. Other times, it could also indicate something mechanically wrong with the air conditioning system. Some smells are a sign of an unsafe situation, such as a natural gas leak.

At Brandywine Heating & Air, we are skilled at diagnosing and fixing these type of problems. If you smell something peculiar coming from your cooling system, chances are our team of skilled pros has smelled it, too—and fixed it! We’ve earned a reputation as the premier company for air conditioning repair in Wilmington.

What does a particular smell wafting out of your air conditioning mean? Here are some typical air conditioner odors and what they might mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it might be because of a buildup of bacteria or fungus in the unit. When moisture accumulates inside the unit, it can establish an environment that is conducive to the spread of bacteria and fungus. This can cause a nasty odor that is often described as smelling like dirty feet.

Another possible cause of the stench of dirty feet could be a dirty air filter. When the air filter becomes choked with dirt, dust and other debris, it can result in poor air quality and a musty smell that bears a resemblance to feet.

To fix 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 regularly to ensure good air quality and prevent the growth of bacteria and fungus.

Your AC Smells Like Rotten Eggs

If your reeks of rotten eggs, it may 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 very dangerous and requires immediate attention. If you suspect a gas leak, turn off your air conditioning system, immediately open windows and doors to allow gas to escape the area, evacuate the building and call your gas company or emergency services immediately.

The Air Conditioning Smells Like Mildew

If your air conditioner is giving off an odor like mildew, it could be due to a collection 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 bears a resemblance to mildew.

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

Regular air conditioning maintenance from Brandywine Heating & Air can help avoid both of these situations, 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 unpleasant scenarios is when the air coming out of your HVAC system smells like urine.

If your air conditioning equipment reeks of urine, it could be traced back to a number of things. One likely cause is a buildup of bacteria or mold in the your HVAC. This can happen if moisture accumulates in the system and creates a wet environment that favorable for bacterial growth. The bacteria can emit a foul odor that some people describe as smelling like urine.

Another potential cause of the stink could be a clogged drain line. The condensation that forms inside the air conditioning unit needs to drain away effectively, but if the drain line becomes filled with debris, it can cause water to back up and build up inside the unit. This can generate a musty smell that can stink like urine.

My Air Conditioner Smells Like Burning Plastic

If your air conditioning system smells like burning plastic, it might be because of an electrical issue with the unit. After a while, the electrical parts in the air conditioning system can wear out or malfunction, which can make a burning smell that resembles plastic.

Another possible root cause of the smell could be a foreign object stuck in the unit. If something foreign gets caught in the air conditioning system, it can heat up and emit a smell that reminds people of burning plastic.

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

The Air Conditioning Smells Like Gas

If your air conditioner 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 odor, often described as smelling similar to rotten eggs or sulfur. That’s because an odor is incorporated into natural gas to make it easily detectable.

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

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 causes an environment that fosters 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 cause a smell like dirty feet.

Another plausible explanation for the smell could be a dead animal or other biological material trapped in the air conditioning system. This often can happen if an animal such as a mouse or bird is trapped inside the unit and dies.

To fix the issue, it’s worthwhile to have a professional check out and clean your HVAC system. They can determine the source of the smell and take the correct steps to remove any contaminants and keep the problem from recurring.

Why My Air Conditioner Smells Like Vinegar

There could be several reasons your air conditioning system smells like vinegar. One possible cause is a dirty air filter. One other potential cause of the smell might be a refrigerant leak. If the refrigerant leaks, it can create a chemical odor that is described as smelling of vinegar.

To fix the issue, it’s essential to have a skilled mechanic inspect and clean your air conditioning.  If the odor lingers after the cleaning and replacing 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 tech can tell you if your air conditioning needs to be replaced.

If you are planning to upgrade, Brandywine Heating & Air can help select the right unit to fit your home’s needs. We deliver reliable, skilled air conditioner installation in Wilmington.

The Air Conditioning Smells Like Chemicals

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

Another possible reason for the smell could be a problem 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 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 hazardous and may require immediate attention to protect against injury or damage to your house.

Strange Smell Coming from the Air Conditioning? Contact the Experts at Brandywine Heating & Air

If your air conditioner stinks and you aren’t able to fix it easily on your own, contact the cooling professionals at Brandywine Heating & Air. We have years of experience working with a wide variety of air conditioning systems. Our crew has fixed many air conditioning problems through the years—including funky smells. Call us today for quality AC repair in Wilmington!