Furnace Maintenance: What a Real Tune-Up Includes (and How Often)

2026-07-01 · By Ahmad, Owner & Lead Technician, IKAD Mechanical · Maintenance

Reviewed: 2026-05-21 · This article is reviewed periodically. Pricing and rebate amounts current as of the date shown.

Furnace maintenance is the cheapest insurance in your home. A proper annual tune-up costs a fraction of an emergency no-heat call, keeps your gas bill down, and is often required to keep the manufacturer warranty valid. The problem is that "tune-up" means very different things to different companies. Here is what a real one includes, and how often you actually need it.

How Often Should You Service a Furnace?

Once a year, ideally in early fall before the heating season starts. We are blunt about why: roughly 80% of the January no-heat calls we run across Halton are on systems that had not been serviced in three or more years. Small, cheap problems, a dirty flame sensor, a marginal igniter, a partially blocked drain, quietly become a 2 a.m. failure in a cold snap. Annual service catches them while they are cheap.

What a Real Tune-Up Includes

When we tune a furnace, this is the checklist. If a quote does not cover most of it, it is a filter change with a fancy name.

• Burners: inspect and clean; check flame quality (should be steady and blue, not yellow or flickering).
• Gas pressure: measure and adjust manifold pressure to spec.
• Heat exchanger: inspect for cracks, the number-one safety item, since a cracked exchanger can leak carbon monoxide.
• Draft and venting: confirm proper draft and clear intake/exhaust.
• Blower: measure motor amperage and check the wheel; verify temperature rise is within the nameplate range.
• Flame sensor and igniter: clean the flame sensor (a common no-start cause) and check the igniter.
• Condensate drain: clear the drain and trap on high-efficiency units.
• Safety switches: test the high-limit, pressure and rollout switches.
• Carbon monoxide: test for CO in the supply air and around the unit.
• Filter: replace or clean, and check static pressure if airflow seems off.

What You Can Do Yourself

Between professional tune-ups, you can handle the easy wins: change a 1-inch filter every one to three months (media filters every 6 to 12), keep the area around the furnace clear, and in winter make sure the outdoor intake and exhaust pipes are not blocked by snow or ice. Everything past the filter, opening the burner compartment, touching the gas valve, or disturbing the heat exchanger, should be left to a TSSA-certified gas fitter. See our furnace no-start checklist if yours quits between visits.

When Maintenance Is Not Enough

If your furnace is 18-plus years old and you are paying for repairs every winter, the math has tipped. A modern 96%-plus furnace (we install York, Luxaire and Coleman) burns far less gas, and there are real rebates on replacement. See our 2026 furnace cost guide to compare.

Ready to book a fall tune-up before the rush? Request a visit or call (905) 491-6943. We do not upsell, if your furnace is healthy, we will tell you.

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