Nice, Knowledgeable & Fast

Bad Smells Coming From Your Furnace Vents & What They Mean

The air that comes out of your heating system or furnace vents should never smell bad to the point where it’s unpleasant. If the air is smelling a little funky or off and you start to notice it, it likely means something within your furnace is malfunctioning. While it could just need a small furnace repair, it could also be a sign of a bigger issue.

Below are some smells that can come from your heating or furnace vents that you should not ignore.

Rotten Eggs

A sulfur smell, or the smell of rotting eggs, is certainly an odor you don’t want in your home. Not only is the odor highly displeasing, it can also be a sign of a gas leak coming from your gas furnace, which is a dangerous situation for the whole family. If you ever smell a rotten-egg odor coming from your vents, you and your family should immediately leave the house and call for help immediately.

Burning Smell

A burning smell from your vents is also unpleasant and poses a safety risk. If you smell a burning odor, it could be due to a component of your furnace or heating system getting too hot, such as a motor or other electrical piece. If you smell what can be described as burning plastic, melting rubber, or hot metal, there may be a part of the furnace that’s burning, which has the possibility of turning into a fire. If you smell this odor, turn off your unit immediately and contact a trusted HVAC company.

Musty, Mildew Odor

If you’re smelling a musty or mildew odor coming from your vents, there is likely a buildup of moisture inside your ducts. Ductwork that has excessive moisture will create an ideal environment for mold to grow. If there’s mold in your air ducts, you and your family will breathe it in, which will have dangerous and detrimental effects on your respiratory system and overall health. If you are smelling a mildew or musty odor, we strongly recommend calling an HVAC company to have it checked out — scheduling an air duct cleaning service is a good idea too. Typically, this type of odor comes from your air conditioner, but it can also come from your furnace too.

Chemical Smell

This is another smell that could be potentially dangerous and should not be ignored. If there’s clearly a chemical odor coming from your furnace vents, such as one that closely resembles formaldehyde, it most likely means there’s a crack in the heat exchanger. The heat exchanger is an important component of a heating system, as it takes heat out of the combustion chamber — but if it’s broken and leaking, there’s a risk of fire and it could possibly be dispelling carbon monoxide into your home.

If you’re smelling a chemical odor coming from your vents, turn your unit off and call a licensed HVAC company immediately to have it checked out.

Contact Us for Local Heating & Furnace Repair & Replacement

Your heating system or furnace should never be emitting any strange or unpleasant odors into your home. If it is, we strongly recommend you give us a call right away to avoid a potentially dangerous situation for you and your family. Moreover, catching and repairing furnace problems early will often save time and money in the long run, as a small issue now can turn into a big, costly problem later without repairs.

Our team of HVAC technicians are trained, licensed, and experienced in all types of heating and furnace system repairs. We’ll identify the problem quickly, and fix whatever the issue may be by recommending the most efficient solution possible.

We service the local Ventura County and San Fernando Valley areas of California, providing heating repairs, furnace repairs, and other heating system services — give us a call today!

Contact Us Today!

Need Fast Service? We're Here to Help!

Office Location

1090 Lawrence Dr. #105
Newbury Park, CA 91320

License #739136


Ventura County


San Fernando Valley