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Central Air Conditioner Smells Like Chemicals? 3 Methods Explained

Blog By Alexandra / July, 06, 2025

If you live in a place that has long spells of summer, an air conditioner unit becomes a necessity. And things get worse when it does not work properly or goes for a toss. Thus, to avoid permanent damage to your AC machine, you need to wary of the signs that your AC sends out. Surprised to know this? Well, it’s true that your AC sends some signals to let you know that something is not right with it And one of those signs that your central air conditioner smells like chemicals.

There could be a lot of reasons behind this “oh-so-awful” smell. In this article, we shall discuss the different types of chemical smell, the reasons behind each smell, and if and how you can fix them.

 Central Air Conditioner Smells Like Chemicals | 3 Type Of Smell

  • Ether-like or chloroform-like smell
  • Paint like or like other common pungent chemicals
  • Acidic, ammonia, or musty

Ether-like or chloroform-like smell

Possible Problem

Refrigerant Leak

What is Refrigerant?

Before we discuss the signs and implications of a refrigerant leak, you need to first understand what a refrigerant is. A refrigerant is a chemical that is found in either a gaseous or fluid state. It has the capability to absorb heat and provide refrigeration when it comes in contact with other components like compressors.

Refrigeration or air conditioning is not possible without a refrigerant. In simple words, a refrigerant is what removes the hot air from your home and fills it with cool air. In an air conditioner, the refrigerant is stored inside copper coils. Often, with the passage of time, these copper coils can crack and leak. This leak could release the chloroform or ether-like smell and that is when you can be sure that it is a refrigerant leak.

Signs of a Refrigerant Leak

Besides the smell, there are other signs that you can note to be sure that it is the refrigerant leak that is guilty of the chemical smell.

  • AC struggling to cool the room
  • Warm air from the vents
  • Bubbling or hissing noise from the AC
  • Ice on the evaporator coil or refrigerant lines
  • High electricity bill

Causes of Refrigerant Leak

The most common cause of a leak is a corroded connection between the coil and the refrigerant line.

How To Fix The Leak?

You need to first identify the leak before getting it fixed. While you can try to identify the leak yourself, we recommend that you get a professional to identify and fix the coil or line. It is because a refrigerant is toxic and flammable too. The system also needs to be recharged with refrigerant after the leak is fixed.

Paint like or like other common pungent chemicals 

Possible Problem

Open chemical containers near the AC’s indoor unit

In most homes, the indoor unit of the AC is kept in basements, the attic, or other closed spaces. And often those are the places where people tend to store their home renovation supplies like cans of paints, cleaning components, or other chemicals. If you leave any of these cans open and if the AC’s indoor unit (also called air handler) is in front of these open can(s), it can pick up the chemical smell and disperse it in your room through the ducts, which makes your room smell of those chemicals.

Signs That There is An Open Can of Chemicals

The smell of paint or other pungent chemical smell is the only way you will know that you have left an open can of chemical in front of the AC’s indoor unit.

How To Fix the Problem?

Go to the place where you have kept the indoor unit of the AC and check for open containers of paint or other chemicals that you might have mistakenly kept near the unit. Close the containers tightly to ensure that there is no leakage and move them to some other place in your home. Yes, it is that simple!

Acidic, ammonia, or musty 

Possible Problem

Mold growth in the evaporator coil or ducts

The perfect environment for the growth of mold is damp and dark spaces and where they can feed on bacteria and dirt. And unfortunately, an AC’s system provides mold the perfect place to grow and prosper. Mold growth is noticed the most during humid months.

Signs That There is Mold Growth in the AC

Besides the acidic or musty smell, you can find out if there is mold growth by peeping into the ductwork. You can also check for mold growth on the evaporator coil.

Causes of Mold Growth

After dehumidifying your home, the evaporator coil gets really cold. There is also a condensation of the moisture from the air on it. This creates the perfect damp and dark environment for the growth of mold.

How To Fix the Problem?

The only solution to the problem is getting rid of the mold. You can do the cleaning yourself by using a self-rinsing foaming coil cleaner. Or you can also call in a technician to do the job for you.

Conclusion

While these are the common reasons that make your central air conditioner smells like chemicals, other issues like ozone from your air filter/cleaner, and glue from your new AC ducts could make your AC’s indoor unit dispense air that smells of chemicals. While in the case of the former, you can try setting your air filter’s setting to low so that it produces less ozone, in case of the latter, you just need to wait till the smell goes off on its own.