If Your Air Conditioner Smells, Here's How to Fix It

When your air conditioner starts putting out strange or gross smells, it is important to take notice because it could be a sign of a significant problem. Ignoring unpleasant smells coming from your cooling system could lead to serious damage to your air conditioning or even pose a risk to your health and safety.

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

At All Solutions Heating & Cooling, we have a nose for these sorts of things. If you smell something peculiar coming from your AC, chances are our team of skilled pros has smelled it, too—and fixed it! We’ve earned the reputation as the premier company for air conditioning repair in Portland.

What does a specific odor billowing coming from your cooling system mean? Here are some frequent air conditioner smells and what they may mean:

My Air Conditioner Smells Like Feet

If your air conditioner smells like feet, it could be due to a buildup of bacteria or fungus inside of it. When moisture collects inside the unit, it can produce an environment that is conducive to the growth of bacteria and fungus. This can produce a nasty odor that is often described as smelling like dirty feet.

Another possible explanation for the stench of dirty feet could be a dirty air filter. When your HVAC system's air filter becomes choked with dirt, dust and other contaminants, it can cause 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 replace the air filter on a regular basis to promote good air quality and restrict the growth of bacteria and fungus.

The Air Conditioning Smells Like Rotten Eggs

If your smells 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 recognizable 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 extraordinarily 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, get everyone out of the building and call your gas company or emergency services immediately.

My Air Conditioner Smells Like Mildew

If your AC smells like mildew, it could be due to a buildup of moisture inside the unit. When moisture forms inside a cooling system, it can promote the growth of mold and mildew. This can cause a musty smell that it similar to mildew.

Another possible reason for the smell may be a dirty air filter. If the air filter becomes clogged, it can lead to poor air quality and a musty smell that is similar to mildew.

Routine air conditioning maintenance from All Solutions Heating & Cooling can help protect against both of these problems, because a good cleaning, inspection and filter change is a terrific way to keep your system running at its best!

The Air Conditioning Smells Like Urine

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

If your air conditioning smells like urine, it could be due to a variety of factors. One potential cause is a accumulation of bacteria or mold in the your cooling system. This can happen in the event that 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 feasible cause of the smell could be a blocked drain line. The condensation that forms inside the air conditioning unit needs to drain away correctly, but if the drain line becomes stopped up by debris, it can cause water to back up and build up inside the unit. This can create a musty smell that resembles urine.

The Air Conditioning Smells Like Burning Plastic

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

Another possible reason for the smell could be a foreign object lodged in the unit. If something foreign gets caught in the air conditioning system, it can heat up and cause a smell similar to burning plastic.

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

Your AC Smells Like Gas

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

As we said before, a natural gas leak can be VERY harmful 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 as soon as possible.

Why My Air Conditioner Smells Like Fish

If your AC smell like fish, this could be a sign of 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 foul 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 can happen if an animal such as a mouse or bird is trapped inside the unit and dies.

To fix the issue, it's important to have a professional examine and clean your air conditioning system. They can identify the source of the smell and take the appropriate steps to remove any contaminants and stop the problem from recurring.

Your AC Smells Like Vinegar

There could be multiple reasons your AC smells like vinegar. One possible cause is a plugged air filter. One other possible cause of the smell might be a refrigerant leak. When the refrigerant leaks, it can create a chemical odor that is described as smelling of vinegar.

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

If you are planning to upgrade, All Solutions Heating & Cooling can help select the correct unit to fit your home’s needs. We deliver trustworthy, professional air conditioner installation in Portland.

Your AC Smells Like Chemicals

If the smell of chemicals is coming out of your air conditioner, it could be due to a refrigerant leak. In a situation where the refrigerant leaks, it can create a chemical scent that is often described as smelling like chemicals or paint thinner, vinegar or acetone.

Another possible reason for 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 believe there is 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 residence.

Weird Smells Coming from Your AC? Contact the Experts at All Solutions Heating & Cooling

If your air conditioner reeks and you aren’t able to fix it smoothly on your own, contact the cooling specialists at All Solutions Heating & Cooling. We have lots of experience working with a wide variety of HVAC systems. Our crew has fixed a multitude of air conditioning concerns over the years—including weird smells. Call us today for quality AC repair in Portland!