why does my furnace smell like brown sugar?At first, a wafting sweet smell from your furnace may be pleasant. But, you’ll want to investigate this smell because, over time, it tends to get stronger and yeast-like. You may start to get headaches and nausea from the smell. Plus, it is typically a sign that something is wrong with your furnace.

To prevent further damage to your furnace, and protect your health, it’s wise to address the smell right away. So, why does your furnace smell like brown sugar and what can you do about it?

Heat Exchanger Issues

That sweet smell may seem a lot less mysterious when you learn that it’s a common symptom of a broken heat exchanger—a critical part of any gas furnace. If your heat exchanger is giving off a brown sugar smell, it may be clogged, cracked, or otherwise broken.

You should call your HVAC technician right away if you suspect your heat exchanger is having issues. Leaking heat exchangers can release dangerous gases along with the sugary smell. An intense sugar smell may mask the rotten egg smell of leaking gas. Or, an odorless gas may be leaking into your home.

Your HVAC professional will be able to check for gas leaks, ventilate your home and replace the broken heat exchanger. If they find a leak you may also need to call your fire department and utility company, as gas leaks can be emergencies.

Check the Vents

If an HVAC professional has checked up on your furnace and not found any problems, the source of the sweet smell could be in your vents instead. Any sugar, from maple syrup to molasses, could have spilled into your kitchen vents. It is counter-intuitive, but gross and decomposing things that are stuck in your vents may smell like sugar too.

Again, your HVAC professional can help locate the smell and clean out whatever is causing it. While they are looking, you should consider investing in a duct-cleaning. A good clean can help improve your air quality even if the smell ultimately isn’t coming from your vents.

Is It a Burning Sugar Smell?

If your air smells like it’s burning when the furnace comes on, typically, you should look for dust. A furnace may get hot enough to burn off dust and create this smell. There are a few other causes an HVAC tech could inspect for you. But, if the burning smell also seems sweet, it may be wise to look for nearby sugar.

It’s rare, but possible, that families who are big on baking could spill enough sugar near their furnace to cause a caramel-like smell when it burns off. If your furnace is near a pantry or cold cellar where you keep sugar or maple syrup, it’s wise to look nearby for spills.

What If It’s Not Your Furnace?

When people find an unusual smell in their home, they typically call us HVAC professionals. That’s a wise move, but it isn’t always the answer. If your air smells sweet, but no one else can smell it (including us), you may be experiencing a phantom odor or another health problem. If we’ve cleared your furnace, it may be time to call a doctor.

How to Learn More

If you need more help figuring out the burning sugar smell in your home, our team can help. Our heating team has diagnosed and fixed a wide variety of furnace issues, including some strange ones, making them uniquely equipped to handle your furnace issues. You can also visit American Standard’s guide to furnace smells and sounds for more information.