5 Different Air Conditioner Smells and How to Solve Them

It’s happened to all of us: a strange smell coming from the air conditioner.

Sometimes it’s noticeable immediately. You enter a room on a hot day with the air conditioning on, and right away, your nose tells you something isn’t right.

Or it can happen gradually. Your AC runs during the hottest times, and day by day, you start to notice a growing unpleasant odor. Soon, you narrow the culprit down to your AC.

What are those air conditioner smells?

Are they dangerous?

And how do you make them go away?

As an experienced HVAC business in Tyler, Texas, ETR knows how frustrating it can be when your air conditioner suddenly starts smelling up the whole house.

Some odors require a simple solution, but others can be potentially dangerous.

If you’re not 100 percent sure what the smell coming from your air conditioner is, contact your local HVAC repair company right away.


1.Does your AC have a chemical smell?

A chemical odor coming from the air conditioner could mean multiple things.

Some air conditioners use Freon to cool the AC unit. If there’s a leak somewhere, the freon will create a chemically, sometimes sweet smell.

Some AC units use different refrigerants, and if there’s a leak in the line or elsewhere, it means the coolant is escaping, and that’s what you’re smelling.

Once you know it’s your air conditioning unit causing the smell, you should turn it off right away and call a technician. In addition, you should open all the windows and keep the home well-ventilated. For their safety, don’t allow children or elderly members of the household to be in the room until the HVAC specialist has diagnosed and fixed the problem.

2.Do you smell smoke from your AC?

The fact is electric appliances can present a fire hazard.

If you smell smoke or the odor of burning plastic, it’s important to immediately check your AC unit.

If you discover smoke or melting plastic, immediately turn off your air conditioner. It is also a good idea to turn off the breaker. Once electricity has been cut to the unit and you’ve confirmed there’s no immediate fire danger, contact your local HVAC experts immediately.

If your air conditioner hasn’t been cleaned in a long time and you have a lot of dust buildup, there’s a chance the burning smell could be coming from an accumulation of dust. Make sure you’re regularly cleaning your ductwork and not allowing dust to build up.


3.Does your air conditioner smell musty?

Especially in humid locations like East Texas, mold and/or mildew can build up in your air conditioner.

Even though air conditioners also serve to remove excess moisture from the air, if they’re not working properly, moisture can build up and create the perfect environment for mold and mildew to thrive.

It’s not only the smell of mold and mildew that’s unpleasant. Mold and mildew can also cause significant issues for the health of anyone in your home, particularly if they suffer from respiratory problems.

The culprit behind this AC issue can be several things, but most often, you can narrow it down to a dirty air filter. A clogged air filter means the airflow in your AC is compromised, and it could cause damage to the compressor or elsewhere if not addressed quickly. While an air filter is cheap and easy to clean or replace, a compressor or heat pump replacement can be costly.

If you notice a musty smell, it’s a good idea to get your AC unit inspected and cleaned by professionals with state-of-the-art products and diagnostic equipment.


4. Does your air conditioner smell like rotten eggs?

If you notice a sulfurous, rotten egg odor suddenly coming from your AC, it’s important to open windows and get proper ventilation into the room as quickly as possible. Once the air is clearing in the room, make sure the unit is turned off. Don’t allow family or pets in the room.

This stinky smell could mean your AC has a dangerous gas leak. A gas leak means the potential for carbon monoxide poisoning.

Call your local HVAC technicians immediately if you suspect you might have a gas leak, and don’t allow people or pets back in the home until the professionals have given you the “all clear.”

5.The unidentifiable stinky smell in your AC?

Unfortunately, sometimes animals get into your HVAC system—and can’t get back out again.

If you have an unidentified bad smell in your air conditioning unit, it could be caused by a dead rodent or bird caught in the air duct. If you’re experienced and/or brave enough, you could attempt a DIY fix and try to remove it yourself, but we recommend calling in an experienced technician.

You don’t want to accidentally break or damage your air conditioner and make more repairs necessary.

It can be frustrating when our HVAC systems aren’t working properly.

However, paying attention and being aware of issues like strange smells coming from the unit means you can usually catch the problems before they get worse and require a new air conditioner.

For safety reasons, if you’re unsure of the odor’s origin, it’s always a good idea to call professional HVAC technicians.