A service, not a glance
A real tune-up takes the better part of an hour with the cabinet open. The burners come out and are cleaned. The flame sensor is polished and the igniter inspected for cracks. The heat exchanger is examined for corrosion and splits, with a carbon monoxide reading taken at the supply air. The blower wheel is cleaned, and the motor and its capacitor are tested under load. Gas pressure at the manifold is measured and set to the rating plate. Each limit, rollout and pressure switch is proved to trip. The intake, the exhaust and the condensate trap are cleared, the filter is changed and the thermostat is checked against a reference.
The last step is a combustion analysis of the flue gases, which is the only way to know that the furnace is burning cleanly at its rated efficiency. Many cheap "furnace inspections" never do it. The full checklist, and why each item is on it, is in how often a furnace needs maintenance.
What it costs and what you get
A complete annual service on one gas or propane furnace, including the combustion analysis and a written report, is typically $139 to $219 in the Ottawa area in 2026. A second furnace, a boiler or a heat pump serviced in the same visit is priced lower. The price is confirmed when you book. Anything the technician finds that needs attention is written up and priced separately, and nothing beyond the service is touched without your say-so.
The case for every autumn
Most furnace makers make annual professional maintenance a condition of the parts warranty, so skipping it can cost you a control board or a blower that would otherwise have been covered. Beyond the warranty, a furnace that is cleaned and set up each year keeps closer to its rated efficiency for its whole life, and the gas it would otherwise waste shows up on the winter Enbridge bills. It also fails less: most of the no-heat calls we take in January trace back to a part that was already on its way out in October.
The best window is late September to mid October, before the first cold snap fills the calendar. If you have let it slide, book it anyway; a mid-winter service is still far better than none. Between services, change a one-inch filter every two to three months through the heating season, sooner in a house with pets or renovation dust.
Maintenance plans
A plan puts the annual service on the calendar for you and moves plan members to the front of the queue when the weather turns and everyone calls at once. Plans usually include a discount on any repair during the year. Ask what the current plan covers and costs when you book.
