Why Does My Heater Smell Like It’s Burning?
If you notice a burning smell coming from your heater, it can be alarming. Learn what’s normal, what’s not, and what to do when your furnace smells like burning.
By Anne Fonda
As the leaves start to change color and the nights start to get colder, homeowners across the country are turning the heat on and asking the same question - why does my furnace smell like burning? In most cases, there’s no cause for alarm.
In this guide, we’ll go over some of the reasons why your heat smells like burning, and what to do about it.
Causes of the burning smell from your heater
If you notice a burning smell from the furnace vents, you may not need to do anything. But you may need to play detective to find the source of the burning odor.
Burning dust
Is it normal for a furnace to smell like burning? Maybe. A common reason for a burning smell when you initially turn on the heat is dust buildup on the furnace. If you live in a region with four seasons, such as the Midwest, Northeast, or Mid-Atlantic, your furnace may sit dormant for months.
This allows dust to accumulate. When you turn on the heat, the accumulated dust ignites, resulting in that burning dust smell permeating your home. The good news is it should only last a few minutes.
Pet hair
If the furnace smells like burning hair, look to your pets as the reason. Our furry friends can shed - a lot. That pet hair can make its way into the air ducts and the furnace filter. When heated, it will smell like the hair is burning.
You can help prevent this smell by changing your filters, vacuuming at least weekly, and investing in a whole-house air cleaner like the AccuClean™ Whole-Home Air Cleaner. It can do a better job trapping pet hair and pet dander, as well as other allergens and pollutants.
Clogged air filter
Dirty air filters can also cause a burning smell. Be sure to change the filters regularly, and check them often if you have pets or it’s pollen season. A clogged air filter can also harbor mold and mildew growth, giving off a musty smell through your air vents.
Debris in the ductwork
If the furnace smells like burning plastic or burning rubber, see if you can pinpoint the room where the smell is the strongest. A burning plastic smell from the furnace may not be because of the furnace itself, but rather debris in the ductwork. Turn off the furnace, and carefully remove the vent where the smell is coming from.
If you see something like a small plastic or rubber children’s toy or piece of plastic wrap, remove it and dispose of it. Put the vent cover/register back, and turn the furnace back on. The smell should dissipate. If the smell persists, call an HVAC service company for help.
New furnace
If your new furnace smells like burning, it may be a result of some of the protective coatings on the unit and should dissipate within an hour of first turning the heat on. To help clear the smell, you can crack some windows or doors to ventilate your home.
If the smell persists, contact your HVAC installer to come visit and verify the system is running safely and get to the bottom of the smell.
When to call for HVAC repair
If you’re asking yourself “Is it safe if my furnace smells like burning?” it is if the smell lasts only a few minutes - it’s likely dust burning. But if the smell is persistent (more than an hour), turn the furnace off and contact an HVAC professional. The scenarios we’ve described above are all temporary, non-dangerous smells.
If the burning smell is persistent, it could mean there is electrical damage or a malfunctioning furnace component such as an overheating blower motor or damaged heat exchanger. An HVAC technician can track down the source of the smell and make any needed repairs, as well as recommendations for keeping your furnace running smoothly and odor-free.
Preventing a furnace burning smell
The best way to prevent a furnace burning smell - or other smell, for that matter, is to schedule a yearly maintenance visit with an HVAC company near you. Ideally, you do this in late summer or early fall, before you turn on the heat for the first time.
As part of a furnace tune-up, the HVAC technician will inspect your furnace, clean various components, and check to make sure everything is in working order. Doing this can prevent the heater from smelling like burning when it’s first turned on.
Change the furnace filters
In addition, check the furnace filter before you turn on the heat for the first time. If you had a cool end to summer, you may have forgotten to change the filter. If it’s dirty, change it, and maintain a regular filter change schedule.
Keep debris out of the ductwork
Last but not least, if you catch a small child pushing something through a floor vent, explain to them why that’s a no-no. Get in the habit of looking into floor vents to see if there’s anything in them that shouldn’t be there.
If you have long-haired dogs or cats, you may need to periodically lift out the floor vents and gently vacuum hair and dust from the visible part of the ductwork directly beneath the vents.
Schedule a furnace tune-up or furnace repair
When was the last time an HVAC professional inspected your furnace? Can’t remember? Schedule a tune-up now to ensure the system is operating safely and at peak performance. Is your furnace struggling to heat your home? Schedule a furnace repair appointment to get your home warm and cozy again.
Contact your local American Standard dealer for all your HVAC service needs.
Anne Fonda, Content Writer at Trane Technologies
A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.
She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism. When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.
Expert review by John Kim, Senior Product Manager, Furnaces
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