Troubleshooting Tips: Furnace Smells and What They Mean

An unusual smell coming from your furnace is almost always a sign there’s something wrong with it. But what does a certain smell mean exactly? 

The Different Smells

• Musty odors – There are usually two culprits behind a musty smell: dirt and dust or mold and mildew in your air ducts. Check your air or furnace filters—mold or dust may have accumulated in them and could be spreading the musty odor. HVAC installation contractors recommend inspecting your filters at least once a year to prevent problems like this.
• Burning dust – Other times, however, dust manages to find its way to the heat exchanger, which in turn burns the dust off, producing this particular odor. Keep in mind that a burning dust smell is normal if you haven’t turned on your furnace for some time—dust may have been accumulating during the time you weren’t using the furnace. The smell should disappear in a few hours, but if it doesn’t, check your air filters.
• Smoke and oil – The smell of smoke and oil from an oil furnace indicates a serious problem, which only a residential HVAC services contractor can properly diagnose and address.
• Electrical, burning smell – This odor could be coming from burning plastic or electrical furnace parts, although it could also come from a foreign object, usually a toy, that got stuck in an overheating air duct. In any case, it’s best to have a technician inspect your furnace as soon as possible.
• Rotten eggs – If you have a gas furnace, a gas leak might be responsible for the smell of rotten eggs in your home. Open your windows to let leaking natural gas out and call an HVAC contractor right away.

When to Call In the Professionals

Of course, the only way to locate the source of the smell is to have a contractor inspect your furnace. Remember: When in doubt, it’s always best to consult an experienced professional. A-1 Comfort Care, an HVAC contractor with more than two decades’ worth of experience, offers furnace and air conditioning repair services. To schedule an appointment with one of our NATE-certified contractors, call us at (732) 578-0379 or leave us a message here. We serve homeowners in Freehold and Wall, NJ, as well as the surrounding communities.