Why Does My Furnace Smell? – WeatherMakers

Why Does My Furnace Smell?

What Do Furnace Odours Indicate?

You know that smell the first time your home furnace fires up–a little bit dusty, a little bit … unnerving? Honestly, that hot dust smell upon first fire-up is OK–nothing to be worried about if it goes away. Your fan has been sitting idle for a couple weeks to a couple months and some dust has settled in the works. It’ll blow clear and diminish in minutes. It’s the other smells that you want to use as an early warning sign that your furnace needs an adjustment or repair. Sniff something weird or unrelenting, take action immediately.

Man adjusts his home thermostat
Sulphur or Hard-Boiled Egg Smell

Here in Canada, natural gas is given a distinct odour so we can recognize when pipes, joints or fittings are leaking. It’s unmistakable because it smells like rotten eggs, or more correctly, sulphur. We do this because natural gas is highly flammable, and we don’t want it floating around in our buildings. Also, it can cause dizziness, nausea, fatigue, and irregular breathing in people and our pets.

In short, if you have a gas-powered furnace that smells like rotten eggs or sulfur, you may have a gas leak. Call your utility provider or an HVAC professional immediately, and follow their instructions. In the meantime, they will rush out with specialized equipment to test the air and track down any leaks.

Corn Chips or Locker Room Stink

Locker-room scents–nobody wants them in their home. These smells can occur when bacteria build up inside your heating system, particularly during shoulder seasons when the system is firing up irregularly here and there. It’s due to condensation accumulating in the system, and though it’s rare in our dry Alberta climate, it does happen. Don’t worry, though, a good, old-fashioned furnace cleaning will sort this out. For tougher cases where the bacteria have migrated into duct work, you can completely eliminate the problem with a full duct cleaning.

Electrical Burning Smell or Ozone

This scent is harder to describe, but you’ll know it immediately when you sniff it. It’s a little bit like air in a rainstorm, or burning wires, or an acrid metallic smell. Your furnace might create a similar smell when it overheats.

As furnaces age, their bearings wear out, and these bearings can in turn cause the blower motor to bind or seize. If the unit doesn’t stop working entirely, it could continue to heat, melting wire insulation, and in some cases causing sparks and arcs. If you smell electrical burning, cut the power to your unit immediately and call an HVAC technician for help. This is a serious issue, and [we suggest annual furnace inspections and tune-ups] to check the health of blower motors mainly to avoid this issue altogether.

Burning or Smoke Smell

This one is simple. Keep the area around your furnace (and hot water heater) clear of debris. If you smell burning or smoke, be sure to check the surrounding area around your furnace. Be sure to always keep the furnace panel screwed in place as well. That piece of metal is what keeps everything from mice to pets to artifacts from your life from coming into contact with the flames inside your furnace.

In Short, Trust Your Nose

If you smell any of the above, don’t hesitate to call WeatherMakers to perform a furnace inspection or make repairs. If you smell something that’s not on this short list but it seems worrisome, persistent, or it’s just plain annoying, call a pro for a quick inspection. Even if there’s no issue, you’ll have gained peace of mind knowing your furnace is running in peak condition.

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