Why Does My Furnace Smell

Nov 19, 2019 | Furnace, Heating, Hilliard-Dublin

Have you ever turned on your furnace and noticed a strange smell? If so, don’t be alarmed, at least not just yet. Older furnaces are notorious for emitting unusual scents. And while some of those scents might be normal, others might not be. How can you tell the difference? Read on! You’re in the right place.





If you notice a smell that seems more like a chemical scent, this is the most significant indication of a crack in your heat exchanger. The heat exchangers’ function is to remove the heat out of your furnace’s combustion chamber and out of your residence. A crack could be very dangerous because it could catch the home on fire or even permitting carbon monoxide to build up. For this purpose, make sure that your carbon monoxide detector always has good batteries. So remember, before you fire up your furnace, replace those old batteries!

Electrical Burning Smell

The electrical wires within your unit are often located very close together. At times, they might even become loose. If you detect an electrical scent, it could mean your system is overheating, or the wires are tangled, causing them to malfunction.

It’s important to remember, these wires are close to metal that could cause them to heat up and possibly even catch on fire. Moving forward, be sure to shut your unit down if you notice this smell and to give us a call right away.


Smoke is plausibly the worst smell you could have come from your furnace. If smoke is coming out of your unit, it can mean only one thing, an obstructed chimney. When your chimney is blocked, there isn’t anywhere else for the smoke from the pilot light to go, other than for it flow back into your home. If this happens, you will need to turn your furnace off promptly and call a professional and open a window.




Burning Dusty Smell

While your furnace is shut down for the summer, it’s natural for your units to grow dusty. This is the most prevalent call we get when a unit is not working properly. You will want first to locate your filter and then have it replaced.

If you continue running your unit like this, when it’s still a small problem, it can lead to something bigger. If there’s one thing you learn here, it’s that you should never ignore simple smells like these. It may mean that air isn’t able to reach the unit.

Oil Smell

When smelling oil, it means only one thing. You need to replace your filter because it is probably clogged. Most HVAC companies offer filters in most sizes. If, after changing the filter, the smell remains, call a professional before proceeding.

Musty Smell

If your unit has been down for a few months, it is normal to smell must once you’ve turned it back on. It might just need to be cleaned off. However, if you clean it off and the smell continues, you will need to let a professional inspect your unit for mold. If your air seems damp and smells musty, this is the most significant sign of mold. Having mold run through your vents can be very poisonous, and it is not a job for just anyone to clear out.


If you have any more concerns beyond what is above or have more questions, please make sure to give call Hilliard-Dublin Heating & Air today at 614-490-7520, or schedule an appointment now at www.hilliarddublinheatingandair.com/schedule-now/. Thank you, and have a great rest of your day!