Why Does My Furnace Smell

Nov 19, 2019 | Furnace, Heating, Winter

Whenever we use our home furnace systems, most of us have faith our unit is going to circulate fresh, warm, and pure air throughout our homes. And on an average day, it does so — with ease. On an average day, we probably will not even think about our furnaces at all, as it runs noiselessly and smooth, not a sight or scent. And then one day you perceive something. You notice something; only it’s not a noise. It’s a fragrance and a peculiar one at that. At points, the aroma overwhelms you and your family, and at other times, you only regard an obscure whiff of the indistinct smell. At times, you might even question whether it’s even arising out of your furnace at all. Regardless of how strong the smell seems, there are sorts of scents you should never ignore, as they often mean there could be an injury to your furnace or a hazard to your family.

To ensure your family stays safe this winter, we at Lewis Center-Powell Heating and Air compile a list of the most frequent smells that could be originating from your furnace and the most probable reasons behind them.




If you discern a smell that resembles a chemical-type fragrance like formaldehyde, it normally suggests only one thing. There could be a fracture in your heat exchanger. A heat exchanger is a component of your home’s furnace system that pushes hot air out of the combustion chamber.

A broken heat exchanger raises the chances of a house fire. It can also emit carbon monoxide fumes into your home.

Because of the dangers for this, make sure you have carbon monoxide detectors throughout your home, and they have functioning batteries.

Electrical Burning Smell

Electrical and metallic aromas ordinarily arise from extreme heat within your home’s furnace. A smell comparable to scorched wires probably suggests a metal part is overheating. A more metallic odor could result from a damaged rubber part.

To avoid a shutdown and reduce the chances of fire, shut down the furnace promptly and give us a call. Have one of our trusted technicians find and replace the parts that are getting too hot.


This is reasonably the most serious smell you could notice coming from your home’s furnace. It normally indicates one thing and one thing alone. Your flue or chimney is blocked up. When your chimney or flue is blocked, the smoke from your furnace’s pilot light has no other way of getting out.

As a consequence, it makes its way into your home. If this happens, you will need to turn your furnace off quickly and call a professional. Don’t wait, either. If the smoke is reasonably faint, you can pull open some windows and then call, but we suggest you to leave your home and get to safety.




It’s typical for your furnace to become dusty, especially if it is located in a basement area like a lot of furnaces. Because your heater is off all summer and spring, your furnace frequently collects dust on its housing and within its interior components. The collected dust ignites and burns up once the weather cools off, after you turn on the furnace.

This aroma is mainly prevalent when you initially use the heater after it’s been off for such a long period of time. Customarily, a burning dust fragrance is not an indication of a critical problem unless it persists for more than 24 hours.

Oil Smell

When detecting the fragrance of oil, it simply indicates it’s time to change your filter. It is probably clogged and needs to be replaced. Most HVAC companies offer a variety of sizes and types of filters. After changing this, if the odor remains, give us a call before letting it go on. Oil smells that won’t go away usually indicate there’s an oil leak somewhere.


The smell of mustiness ordinarily arises when the furnace has gotten some dampness inside. If the odor is faint and it disappears after running the heater for a few hours, don’t fret about it. The problem resolved itself. However, if the smell does not pass after a few days, there could be mold in your furnace system, and it’s circulating a damp fragrance within all of your treated air. Because mold can be hazardous to you and your family’s health, call an expert to assess the seriousness of this dilemma as soon as possible. No one wants to be breathing mold all day lone.


If you have any concerns we haven’t covered above or have more questions, please make sure to call Lewis Center-Powell Heating & Air today at 614-4907530 or schedule an appointment online now at www.lewiscenterpowellheatingandair.com/schedule-now/.

Thank you, and have a blessed day!