Check both the conditions and the locations
Ontario’s carbon monoxide guidance says a house requires CO alarms if it has a fuel-burning appliance, fireplace or attached garage, or receives heated air from a fuel-burning appliance outside the home. For applicable houses, alarms belong adjacent to each sleeping area and on every storey, including levels without sleeping areas. The expanded requirements took effect January 1, 2026.
Apartment and condominium requirements depend on the unit and building. Ontario includes units with fuel-burning appliances or fireplaces, units directly beside, above or below certain service rooms or garages, and units receiving heated air from an outside fuel-burning appliance. Its guidance sets out alarm locations in applicable units and additional requirements for certain heated public corridors.
Bring building-specific questions to the fire department. A neighbour’s layout may not establish which requirements apply to your own home.
Know the alarm response before it is needed
If a CO alarm sounds, leave the building immediately and call 911 from outside or another safe location. Do not wait for someone to feel unwell. Carbon monoxide cannot be identified by its colour or smell.
Test alarms monthly and follow the manufacturer’s instructions for replacing batteries and the device. Ontario distinguishes a low-battery or end-of-life chirp from an emergency alarm; learn the signals for the equipment installed in your home.
The City also recommends annual maintenance of fuel-burning appliances by a qualified technician and keeping outside vents clear. Never run vehicles, generators or other fuel-burning equipment in enclosed spaces.