Carbon monoxide rules to change in Ontario for 2026 and update affects most homes

Ontario is rolling out new, strict carbon monoxide safety rules, and they'll affect almost every type of home across the province next year. 

Starting Jan. 1, 2026, updates to the Ontario Fire Code will expand where carbon monoxide alarms are required in houses, apartments, condos, as well as rental units, and here's everything you need to know. 

Carbon monoxide (CO), often referred to as the "silent killer," is an invisible, odourless gas produced when fuels, such as propane or natural gas, do not burn completely in appliances, including furnaces, stoves, hot water heaters, and gas or wood fireplaces. 

The provincial government notes that over 65 per cent of CO-related injuries and deaths in Ontario happen in the home, hence the updated regulations. 

If you live in a house, a CO alarm must be installed if you have a fuel-burning appliance, fireplace, attached garage, or if your home is heated by air from a fuel-burning appliance that is not contained within the residence (comes into effect on Jan. 1, 2026). 

There are several locations where a CO alarm must be installed in a house, including adjacent to each sleeping area, and on every storey of your home, even those that do not have sleeping areas (comes into effect on Jan. 1, 2026). 

For apartments or condos, a CO alarm must be installed if your unit has a fuel-burning appliance or fireplace, the building has a service room, and your unit is located above, below, or beside the room, the building has a garage, and your unit is located directly above, below, or beside it, or if your unit is heated by air from a fuel-burning appliance that is not contained within your unit (comes into effect on Jan. 1, 2026). 

In an apartment or condo, a CO alarm must also be installed adjacent to each sleeping area, on every storey of your unit (comes into effect on Jan. 1, 2026), and in public corridors of the building if they are heated by air from a fuel-burning appliance (comes into effect on Jan. 1, 2026). 

Building owners will be responsible for complying with the updated carbon monoxide alarm requirements, and landlords will be responsible for installing and maintaining CO alarms in their rental units, testing alarms annually, and providing tenants with a copy of the alarm's maintenance instructions. 

Tenants will be responsible for notifying their landlord of any issues with the CO alarm in their unit. The provincial government also notes that it's against the law for anyone to remove the batteries or tamper with CO alarms in any way.