Why Is There a Burning Smell When You Turn on Your Heat?

As soon as the evenings start turning colder, people flip on the furnace. You might have to turn it off midday, but the evenings are just too chilly to leave the furnace off. Yet, every year your home smells like it’s burning down. Understanding what causes that smell will help you avoid some embarrassing phone calls to the fire department and HVAC repair technicians.

Dirt in the Furnace

Cold air return vents suck everything up at floor level and pull it back into the furnace. This includes dust and pet hair. When it accumulates, you get a lot of dirt in the furnace. Turning the furnace on to heat cold air results in the lint and dirt burning up. Don’t worry. It can’t start a fire unless your ducts and vents are cut off with dust bunnies. If you clean out the ducts and maintain the furnace, this burning smell cause disappears.

Ignition Wiring

There’s an ignition switch with metal wiring attached in every furnace. It heats up and makes a metallic odor that blows up through the vents into the home. It will dissipate as the furnace is turned on more often. If the smell persists over a week or gets worse, get an HVAC technician to check it. It may be that the wiring is burning so hot it melts, although that is less common.

Dirty Air Filter

The air filter is responsible for cleaning the heated air as it is pumped back up into the rooms in your home. If you can’t remember the last time you changed the furnace filter, it is time to change it. Most filters should be changed once a month, although you can pay extra for filters that can last two or three months before changing. The long and short of it is to maintain your furnace and ventilation system. Keep it clean and cleared out. Your HVAC technician can help.