In most of Canada your furnace runs hard for half the year. A little maintenance keeps it efficient, extends its life, and prevents the worst-case scenario: a failure during a cold snap.
Replace the filter regularly
Check the furnace filter every one to three months during heating season and replace it when dirty. A clogged filter restricts airflow, raises your energy bill, and strains the system.
Book an annual service
Have a licensed HVAC technician service the furnace once a year, ideally in early fall. They'll clean the burners, check the heat exchanger for cracks, test safety controls, and confirm it's venting properly.
Warning signs to watch for
Yellow rather than blue burner flames, frequent cycling, unusual noises, rising heating bills, or uneven heat all point to a furnace that needs attention. A cracked heat exchanger is a carbon monoxide risk — never ignore it.
When to replace
Furnaces last 15 to 20 years. If yours is in that range and needs a major repair, compare the repair cost against a new high-efficiency unit, which can cut heating bills significantly.