Furnace Tune-Up Checklist Before a Lake Simcoe Winter

Homes along the Lake Simcoe shoreline deal with wind-driven cold, higher humidity swings, and — on older cottages-turned-year-round homes — duct runs and mechanical rooms that were never really designed for full-time winter heating. A furnace that's been coasting all summer needs a real check before it's asked to run flat-out through a January wind off the lake.

Before anything else: burner and ignition condition, gas pressure where applicable, and a look at the heat exchanger for cracks or corrosion. This is the part that actually matters for safety, and it's the part a rushed "filter and go" visit skips entirely.

A proper tune-up measures temperature rise against the manufacturer's spec and checks static pressure — the numbers that tell you whether the furnace is actually working correctly, versus just turning on. On lake properties with additions or older ductwork, airflow is often the real issue behind a furnace that runs constantly but never quite keeps up.

Well water, higher ambient humidity, and older basements near the shoreline mean we also check condensate lines, drain paths, and — on high-efficiency furnaces — the PVC venting and condensate trap for buildup. A clogged condensate line is a common cause of a furnace that locks out on the coldest night of the year.

Burner and ignition, gas pressure, heat exchanger condition where access allows, temperature rise, limit and rollout switches, condensate drainage, filter and static pressure, thermostat operation, and CO alarm presence. You get the readings, not just "looks fine" — and if something's trending toward failure, you hear about it in October, not during the first cold snap.