Should it smell weird when your furnace kicks in?

Posted by on Monday, October 31st, 2016 at 8:38pm.

Autumn in Southern Alberta – that lovely time when you turn on your forced-air furnace for the first time since spring and an odd burning smell blows through your home.  Is it normal or does your gas furnace need a tune up?

It could be something simple like dust or a filter that needs replacing.  But it might possible be something in the electrical system.  Do you know for sure?  Read on….

Your Dad Says It’s Burning Dust

Perhaps you remember being a kid and smelling that interesting furnace smell in late fall when your parents finally gave in and turned on the heat.  It’s burning dust, you were told.  Dust collects on the heat exchanger in your furnace over the summer months and when the fan starts to blow that hot air the smell wafts through the vents.  This is normal.  If you have smelled this every autumn, then it’s a familiar smell and there’s no cause for concern.

What About Musty Smells?

Another less familiar odour might be something that smells like a damp basement. This type of smell comes from dirt and dust that’s been sitting in the ductwork.  This is a smell that might not dissipate and could be a sign that the air filter needs changing or that the ducts need cleaning.  The latter is a chore than should be done every five years.   Perhaps it’s the filter in your furnace’s humidifier that requires cleaning.  If so, mix equal parts water and vinegar and soak the filter for an hour or so then wipe gently with a cloth.

The Acrid Smell of Burning Electrical

This type of smell in your home is much different than burning dust.  It might smell like burning plastic and this should be investigated rigorously.   If the smell is there but faint, you could check for random objects in the ductwork like a small toy – that type of thing is easy.  But a strong smell could point to more serious issues such as the fan motor overheating.  An expert might have to come in a check for cracks in the heat exchanger.

What Would Cause a Smell Like Oil or Smoke?

Here in Western Canada we don’t have many oil-fired furnaces cranking out heat all winter long.  No oil truck trundling down the street with its trusty hose delivering monthly rations of oil to the basement tank.  If you live on a rural property with an oil furnace, you’re aware that the house smells like oil on delivery day but if it smells like oil on any other day then you have an issue that requires immediate attention.

Rotten Eggs

The slight sulphuric smell has been added to natural gas so that home owners and technicians are aware of a leak.  Otherwise, gas is odourless.  If you detect this, turn off the furnace and open windows to let fresh air in.  If the odour is very strong you’ll want to get out of the house too. Call the gas company from your car or from the neighbours.

Leave a Comment