The Furnace Repairs We See Most in Toronto Homes
After enough service calls, patterns show up. In Toronto homes, from older semis with mid-efficiency furnaces to newer townhouses with high-efficiency units, the same handful of repairs come up again and again.
Hot surface igniters
The igniter glows red-hot to light the gas. It’s a ceramic part and eventually cracks. Symptoms: the inducer fan starts, you hear clicks, but no flame. Touching the igniter with bare fingers during replacement shortens its life, which is a common DIY mistake.
Flame sensors
A thin rod that confirms the burner is lit. Oxide builds up on it and the furnace shuts off after a few seconds. Cleaning fixes it most of the time.
Pressure switches and condensate problems
High-efficiency furnaces use a pressure switch to confirm the venting is clear. A plugged condensate trap, a cracked hose, ice in the vent pipe in a cold snap, or a weak inducer motor can all trip it. The switch itself is often fine; the problem is what it’s detecting.
Blower motors and capacitors
If the furnace lights but no air comes out of the vents, or the blower hums but doesn’t spin, it’s often the run capacitor (on PSC motors) or the motor itself. Dirty filters shorten blower motor life a lot.
Control boards
Less common than people think. Boards fail from power surges, water dripping from an AC coil or humidifier above, or age. Before replacing one, we confirm it’s really the board and not a sensor or wiring problem upstream.
Limit switch trips
The furnace overheats and shuts the burners off. Almost always an airflow problem: filter, closed registers, a dirty AC coil sitting on top of the furnace, or undersized return ducts.
Our furnace not turning on guide walks through the safe checks you can do yourself. For repairs in Toronto and the GTA, see our heating services or contact us at 647-657-2977. Emergency service is available 24/7.
