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

Depending on what you're smelling, 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 even indicative of a harmful situation, like a natural gas leak.

At Pliescott HVAC Services LLC, we are skilled at diagnosing and fixing these type of problems. If you smell something odd coming from your cooling system, there's a good chance our team of qualified pros has smelled it, too—and fixed it! We’ve earned the reputation as the go-to team for air conditioning repair in Cambridge.

What does a certain smell coming from your air conditioning mean? Here are several typical air conditioner odors and what they could mean:

Your AC Smells Like Feet

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

Another possible explanation for the smell might be a dirty air filter. When the air filter becomes filled with dirt, dust and other debris, it can result in low air quality and a musty smell that bears a resemblance to feet.

To fix this unpleasant situation, 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 change the air filter on a regular basis to provide good air quality and prevent the development of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your air conditioning unit smells like 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 very 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 immediately.

Your AC Smells Like Mildew

If your air conditioner emits a smell like mildew, it could be due to a accumulation of moisture inside the unit. When moisture accumulates inside a cooling system, it can cultivate the growth of mold and mildew. This can cause a musty smell that it similar to mildew.

Another possible explanation for the smell may be a clogged air filter. Once the air filter becomes clogged, it can cause poor air quality and a musty smell that has a resemblance to mildew.

Routine air conditioning maintenance from Pliescott HVAC Services LLC can help protect against both of these issues, because a good cleaning, inspection and filter change is a terrific way to keep your system working at its best!

Your AC Smells Like Urine

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

If your air conditioning stinks like urine, it could could be caused by multiple factors. One possible cause is a accumulation of bacteria or mold in the your HVAC. This can happen when moisture accumulates in the system and creates a damp environment that is conducive to bacterial growth. The bacteria can produce a foul odor that some people describe as smelling like urine.

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

Your AC Smells Like Burning Plastic

If your air conditioner smells like burning plastic, a possible cause could be an electrical issue with the unit. After a while, the electrical components in the air conditioning system can wear out or bust, which can make a burning smell that resembles plastic.

Another possible root cause of the smell could be a foreign object lodged in the HVAC system. If something foreign gets trapped in the air conditioning system, it can get hot and result in a smell similar to burning plastic.

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

My Air Conditioner 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 smell, often described as smelling of rotten eggs or sulfur. That’s because this scent is put into natural gas to make sure that it is easily detectable.

As we said 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, leave the building and call your gas company or emergency services right away.

Why My Air Conditioner Smells Like Fish

When your AC smell like fish, you may have a situation where there's a build-up of bacteria or mold in the unit. Moisture creates an environment that promotes 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 create a smell like dirty feet.

Another possible cause of the smell could be a dead animal or other biological material trapped within 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 correct the issue, it's important to have a professional check out and clean your HVAC system. They should be able to determine the source of the smell and take the proper steps to remove any contaminants and keep the problem from recurring.

The Air Conditioning Smells Like Vinegar

There could be multiple reasons an AC smells like vinegar. One possible cause might be a dirty air filter. Another possible cause of the smell could be a refrigerant leak. When the refrigerant leaks, it can create a chemical odor that is similar to vinegar.

To fix the issue, it's essential to have a skilled specialist examine and clean your air conditioning.  If the odor lingers after the cleaning and exchanging 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, they can tell you if your air conditioning should be replaced.

If you are planning to upgrade, Pliescott HVAC Services LLC can help select the ideal unit to fit your home’s needs. We offer dependable, professional air conditioner installation in Cambridge.

Your AC Smells Like Chemicals

If the smell of chemicals is emitting out of your air conditioning unit, it could be caused by 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.

One other possible reason for the smell could be something wrong with the electrical wiring or parts inside the air conditioning system. This can result in a burning smell that it similar to chemicals or burning plastic.

If you believe there is a refrigerant leak or an electrical concern, it's important to turn off your air conditioning system right away 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.

Strange Smell Coming from Your AC? Call the Pros at Pliescott HVAC Services LLC

If your air conditioner reeks and you aren’t able to fix it quickly on your own, contact the cooling experts at Pliescott HVAC Services LLC. We have years of experience working with a wide variety of AC systems. Our crew has fixed a multitude of air conditioning concerns throughout the years—including weird smells. Call us today for quality AC repair in Cambridge!