Every Storey, Every Alarm: Getting Your Furnace and CO Alarms Ready for the 2026 Ontario Rules

Canadian context

Ontario's 2026 heating-season check has two separate parts. First, the supplied April 7, 2026 Hamilton guide reports that the federal efficiency rule applies when a new gas furnace is installed in Canada: it must meet a minimum 95% AFUE rating. The same source says an existing furnace may continue operating regardless of its rating. Second, the supplied sources report that, effective January 1, 2026, Ontario Regulation 87/25 under the Ontario Fire Code requires a working carbon monoxide alarm on every storey of a home with a fuel-burning appliance, including the basement, plus one adjacent to each sleeping area. Furnaces, water heaters, and stoves are examples of fuel-burning appliances; an attached garage is also identified as a reason to check coverage.

There is no gas-furnace ban in Ontario in the supplied evidence. The practical distinction is this: an existing system is not automatically due for replacement because of its efficiency rating, while a replacement has a stated efficiency minimum and may involve permits and qualified installation. Timing matters too. The supplied winter-readiness material contrasts a fault found on a 14-degree September afternoon, which may allow a scheduled visit, with the same fault on the first minus-5 night, when contractors may be booked. That is planning context, not a service guarantee. This issue is a readiness and record-keeping guide, not a furnace diagnosis or a determination that a particular home complies.

Dated evidence

• The April 7, 2026 Ontario Gas Furnace Rules: 2026 Guide for Hamilton Homeowners reports the 95% AFUE minimum for new gas furnaces, continued operation for existing furnaces, the January 1, 2026 CO-alarm change, and the need for a TSSA-licensed technician and municipal permit for installations. It also reports that gas furnaces are not banned and that non-compliance can lead to fines or fire-department inspection. Because those are legal and enforcement claims from a secondary source, verify current details with the relevant official authority.
• The Furnace Ready for Winter: 8 Easy Checks guide places the homeowner check in late September or early October, before a first cold snap. It identifies filter replacement, open registers, a clear area around the furnace, outdoor vent checks, alarm tests, a humidifier restart where applicable, and one test cycle as no-tools checks. It draws a firm boundary around gas work and anything inside the furnace cabinet.
• The Old Furnace in Toronto: Replace Before January or Wait? article reports that Ontario's Home Renovation Savings program does not rebate a gas furnace and covers heat pumps among other upgrades. Treat that as a dated program claim: check the administrator directly before making a financial decision.
• The Canadian Association of Home & Property Inspectors' fall maintenance checklist recommends checking roofs, gutters, and possible air, moisture, and water penetration so small problems do not become larger ones.
• The September 2026 2026 Fall Home Maintenance Checklist for Ontario Homes groups furnace filters, leaks, windows and doors, outdoor water lines, roofs, gutters, smoke alarms, and CO alarms into seasonal preparation.
• A 2026 landlord maintenance checklist for Niagara Falls reports a local snow-clearing by-law taking effect October 1, 2026. It says property owners must keep sidewalks clear of snow and ice; confirm the current municipal requirement if it applies to your property.

Practical checklist

Use a mild day in late September or early October. Keep the work outside the furnace cabinet and do not work on gas connections.

• Set the thermostat to heat and run one complete test cycle. Note unusual sounds, smells, failure to start, or an unexpected shutdown rather than trying to diagnose the cause.
• Install a fresh filter of the size and type specified by the equipment or filter label, and open every register.
• Keep at least one metre clear around the furnace. Check outdoor vent pipes for leaves, nests, snow, or other visible blockage without dismantling them.
• Test every CO alarm and smoke alarm. Record the result and expiry date. Check that CO coverage includes every storey, including the basement, and an alarm adjacent to each sleeping area under the reported 2026 rule.
• If the home has a humidifier, restart it according to its equipment instructions.
• From the ground or with binoculars, look for damaged, loose, or missing roof shingles. Clear gutters and downspouts before freeze-up if they can be reached safely.
• Look for drafts around windows and doors, signs of water leakage, and exterior water lines that should be shut off or drained according to the system instructions.
• Record the date, what you observed, and what needs follow-up. If an alarm is not working, a CO alarm activates, gas is suspected, or the furnace shows a safety finding, leave the equipment untouched and use local emergency or qualified-professional guidance.

Where professional help begins

The homeowner portion ends at observation and routine, no-tools checks. Anything involving gas, the inside of the furnace cabinet, repairs, installation, or permit-related furnace work belongs with a qualified TSSA-certified gas technician and the relevant municipality. Do not treat this article as permission to open, adjust, or repair fuel-burning equipment.

Bring these prompts to a qualified professional:

• Is the current furnace safe to run through another winter, and are there findings that should not wait?
• If replacement is needed, does the proposed unit meet the reported 95% AFUE minimum, and what installation, venting, drainage, or permit requirements apply to this home?
• Are the CO alarm locations and equipment dates appropriate for this floor plan under the current rule?
• Which program administrator should confirm current rebate eligibility, if any, before a purchase is made?

Evidence limits

The supplied research is mainly trade, contractor, inspection-association, and home-maintenance material; it does not include a linked official Ontario regulation, TSSA page, municipal permit page, or program-administrator page. The links above disclose where the dated claims came from, but they are not a substitute for checking current official requirements. Code, permit, product, rebate, and municipal by-law details can change, and a condo, rental, or other building may have additional obligations. This issue does not provide individualized legal, insurance, financial, structural, electrical, plumbing, HVAC, construction, or contractor advice, and it makes no safety or savings guarantee.