Furnace maintenance before winter: what a tune-up includes

A furnace works hardest when you can least afford it to stop. An annual tune-up is the difference between a planned visit in October and an emergency call in January.

What a tune-up covers

• Inspecting the burners and heat exchanger for cracks and wear.
• Checking the flame sensor and ignition.
• Testing safety controls and the venting, including for carbon monoxide.
• Checking the blower, belts and motor.
• Replacing or cleaning the filter.
• Checking the thermostat is reading and switching correctly.

Who can do it

Gas furnaces in Ontario are serviced by technicians certified under the Technical Standards and Safety Authority (TSSA), working for a TSSA-registered contractor. Ask for the certificate before work starts.

Signs it needs a look now

• It turns on and off every few minutes.
• Rooms heat unevenly, or not at all.
• Banging, squealing or rattling when it starts.
• A yellow, flickering flame instead of a steady blue one.
• Your gas bill rose with no change in use.