Why annual — not 'when it acts up'
A furnace can run with a cracked heat exchanger, failing inducer motor or drifting gas pressure long before you notice symptoms. Annual service catches these while they're cheap: combustion analysis reveals incomplete burning, a static pressure reading exposes duct restrictions, and an amp-draw test shows a blower motor heading toward failure. Waiting for symptoms usually means an emergency call in January — the most expensive possible timing.
What a proper furnace service includes
Expect combustion analysis with a calibrated analyzer, heat exchanger inspection, burner and flame-sensor cleaning, gas pressure verification against the rating plate, safety-limit and pressure-switch testing, condensate trap cleaning on high-efficiency models, blower inspection, and filter replacement. If the visit takes fifteen minutes and no instruments come out of the bag, it wasn't a service.
The BC-specific factors
Coastal humidity is hard on venting and secondary heat exchangers, and many Lower Mainland furnaces sit in crawlspaces or garages where damp accelerates rust. High-efficiency condensing furnaces — now the majority of installs — also produce acidic condensate that must drain freely; a blocked trap is one of the most common no-heat calls we see after the first cold week.
Older furnace? Service is also your planning tool
Gas furnaces typically last 15–20 years. From about year 12, the annual service doubles as a condition report that tells you whether to budget for replacement — and whether a heat pump conversion makes sense, given the provincial and utility rebates available for switching. We give you the measured data and let the numbers drive the decision.