Carbon monoxide (CO) is often called the silent killer for a reason — it’s colourless, odourless, and virtually impossible to detect without an alarm. Even low-level exposure can cause headaches, dizziness, or confusion; higher levels can be fatal within minutes. With most CO incidents linked to fuel-burning appliances, fireplaces, or vehicles running in attached garages, early detection is everything.
Starting January 1, 2026, updates to Ontario’s Fire Code will come into effect to strengthen CO protection in homes and residential buildings. Here’s what’s changing — and what homeowners, landlords, and property managers should do now to stay ahead of the rules.
What’s Changing in 2026
Ontario is expanding carbon monoxide alarm requirements through Ontario Regulation 87/25, amending the Fire Code O. Reg. 213/07. The goal is simple: ensure CO detection in any building where a fuel-burning appliance or attached garage creates a risk.
Key updates to the Ontario Fire Code include:
More alarms required in homes
If you live in a detached home, semi, townhouse, cottage, or similar dwelling with:
- a fuel-burning appliance,
- a fireplace,
- an attached garage, or
- ducted heat from a fuel-fired appliance located elsewhere
…you must continue to have a CO alarm near every sleeping area and now must add an alarm on every storey – including basements and floors without bedrooms.
More coverage in multi-unit buildings
Apartments, condos, hotels, motels, boarding houses, and retirement homes will all see expanded requirements. CO alarms will be required in:
- suites adjacent to service rooms with fuel-burning appliances,
- suites adjacent to parking garages,
- service rooms themselves, and
- in some cases, public corridors heated by fuel-burning systems.
Special rules for care and treatment occupancies
Group homes, care facilities, and retirement homes face stricter installation rules to protect residents who may need assistance evacuating.
Enforcement and responsibility
- CO alarms may be hardwired, battery-operated, or plug-in, and combination smoke/CO units are acceptable if properly certified. If hardwired or plug-in, the alarm must have a battery backup that will kick in if a power failure occurs.
- Property owners, including landlords and condo boards, are responsible for installation and maintenance.
- Tenants must not remove or disable alarms and must report issues.
- Non-compliance can result in fines ranging from tickets in the hundreds to more significant penalties for repeated violations.
Quick Safety Tips to Prepare Before 2026
Whether you’re a homeowner, landlord, or managing multiple properties, the best time to get ready is now.
1. Map your fuel-burning appliances
Identify anything that burns fuel: furnaces, water heaters, woodstoves, fireplaces, generators, and attached garages. Have fuel-burning appliances and venting inspected and maintained regularly by qualified technicians to reduce CO risk. This will help you determine where alarms must be installed under the new rules.
2. Install alarms on every storey NOW, not later
Getting ahead of the January 1, 2026 deadline gives you time to test placement, budget for upgrades, and ensure consistent coverage across all levels.
3. Don’t forget maintenance
Test alarms monthly and replace a unit or its battery if it fails a test and according to the manufacturer recommendations. Batteries should be replaced at least annually. For landlords and property managers, incorporate testing into routine maintenance schedules and keep documented records. Landlords are responsible for testing units when a change of tenancy occurs or changes are made to the electrical system. Landlords must also provide tenants with a copy of the alarm’s maintenance instructions.
4. Ventilation matters, keep exhaust outside
Never run unvented fuel-burning equipment indoors, and don’t idle vehicles in garages, even with the door open. Garages trap exhaust and CO can seep into living spaces through doors, cracks, and shared ventilation
Staying Compliant with Confidence
Managing compliance across multiple units or complex building systems can be a lot—especially when requirements change. ECOH provides practical guidance to help you stay safe, compliant, and confident in your next steps. For a more complete approach to risk management and compliance, our Occupational Health & Safety team is also available to support your organization.
