When your air conditioner starts emitting odd or unappealing odors, it is important to take notice because it could be a sign of a big problem. Ignoring unpleasant smells coming from your air conditioning can lead to additional damage to your air conditioning or even pose a risk to your health and safety.

Depending on the smell, the root of the problem might be bacteria or fungus in the system. In other cases, it could also signal something mechanically wrong with the air conditioning system. Some smells are even indicative of a hazardous situation, such as a natural gas leak.

At Heartland Heating & Cooling, we have a nose for these sorts of things. 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 a reputation as the premier company for air conditioning repair in Des Moines.

What does a particular smell billowing from your AC mean? Here are several typical air conditioner smells and what they might mean:

The Air Conditioning Smells Like Feet

If your air conditioner smells like feet, it could be caused by a buildup of bacteria or fungus in the unit. When moisture builds 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 feet.

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

To correct 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 replace 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 air conditioning equipment smells like rotten eggs, it could be the result of a natural gas leak in the unit or in the surrounding area. Natural gas has a unique odor, often described as smelling like rotten eggs or sulfur, which is added to it to make it easily detectable.

A natural gas leak can be extraordinarily 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 at once.

Your AC Smells Like Mildew

If your cooling system is giving off an odor like mildew, it may be due to a accumulation 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 reason for the smell could be a clogged air filter. If the air filter becomes clogged, it can result in poor air quality and a musty smell that resembles mildew.

Routine air conditioning maintenance from Heartland Heating & Cooling can help prevent both of these issues, because a good cleaning, inspection and filter change is a great way to keep your system working at its best!

My Air Conditioner Smells Like Urine

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

If your air conditioning stinks like urine, it could could be caused by multiple factors. One possible cause is a collection of bacteria or mold in the air conditioning system. This can happen in the event that moisture accumulates in the system and creates a moist environment that favorable for bacterial growth. The bacteria can create a foul odor that resembles urine.

Another feasible cause of the stink could be a clogged 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 build up inside the unit. This can generate 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 issue with the unit. After some time, the electrical components 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 HVAC system. If something foreign gets caught in the air conditioning system, it can heat up and result in a smell like burning plastic.

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

The Air Conditioning Smells Like Gas

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

As we said earlier, a natural gas leak can be VERY hazardous and requires 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 call your gas company or emergency services right away.

My Air Conditioner Smells Like Fish

When your air conditioner 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 disgusting odor that can be 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 stuck inside 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 solve the issue, it's important to have a professional examine and clean your air conditioning system. They can find the source of the smell and take the appropriate steps to remove any contaminants and stop the problem from recurring.

Why My Air Conditioner Smells Like Vinegar

There could be several reasons an AC smells like vinegar. One possible cause is a plugged air filter. One other potential cause of the smell might 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 specialist inspect and clean your air conditioning.  If the odor lingers after the cleaning and changing of the air filter, it's best to reach back out to a professional to diagnose and repair any persistent issues with your air conditioning. Or, the mechanic can tell you if your air conditioning ought to be replaced.

If you are wanting to upgrade, Heartland Heating & Cooling can help select the ideal unit to fit your home’s needs. We deliver reliable, expert air conditioner installation in Des Moines.

My Air Conditioner Smells Like Chemicals

If the smell of chemicals is emitting 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 odor that is often described as smelling like chemicals or paint thinner, vinegar or acetone.

Another possible source of the smell could be problems with the electrical wiring or parts inside the air conditioning system. This can produce a burning smell that is like chemicals or burning plastic.

If you think your system has a refrigerant leak or an electrical problem, it's important to turn off 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 protect against injury or damage to your house.

Strange Smell Coming from the Air Conditioning? Call the Pros at Heartland Heating & Cooling

If your air conditioner reeks and you aren’t able to fix it quickly on your own, contact the cooling experts at Heartland Heating & Cooling. We have plenty of experience working with a wide variety of cooling systems. Our crew has fixed countless air conditioning concerns through the years—including strange smells. Call us today for quality AC repair in Des Moines!