Everything you need to know about carbon monoxide alarms

Detecting carbon monoxide

A carbon monoxide alarm is a device that detects carbon monoxide (CO) in your home and sounds an alarm to evacuate when the level of CO becomes too dangerous.

CO is silent, colourless, odorless and tasteless - making it almost impossible to detect without the help of an alarm. It can occur naturally from forest fires and volcanic eruptions, but occurs mostly commonly in our homes from the incomplete combustion of fuels. When the gases released in the burning of these fuels are not properly ventilated out of the building, CO levels inside the building start rising.

Installing carbon monoxide alarms

The Ontario Building Code and Ontario Fire Code regulate the locations where carbon monoxide alarms are required in your home.

Residential buildings must have a working carbon monoxide alarm if they have:

• An attached garage;
• A woodburning fireplace; or
• A fuel-fired appliance, such as a gas stove, gas water heater, or gas fireplace

In detached homes and townhouses, carbon monoxide alarms must be installed in any hallway immediately outside of a bedroom, including basement hallways.

For example, in a two-storey house that has bedrooms in the basement, main floor and second floor, a carbon monoxide alarm would be required in each of the three hallways.

This PDF guide can help homeowners identify where to install carbon monoxide alarms in a houseOpens in a new tab or window (link is external).

In apartment and condo buildings, carbon monoxide alarms must be installed in:

• A hallway or other area immediately outside of the bedrooms, if the unit contains a fuel-fired appliance.
• A hallway or other area immediately outside of the bedrooms, if the unit shares a wall, floor or ceiling with:
  • A service room containing a fuel-fired appliance, or
  • A parking garage.
• Within a service room, if located outside of a suite, where a fuel-fired appliance is installed.

For example, in a one-bedroom condo with a gas fireplace in the living room, a carbon monoxide alarm would be installed immediately outside the bedroom.

This PDF guide can help landlords identify where to install CO alarms in an apartment or condo buildingOpens in a new tab or window (link is external).

Carbon monoxide alarm testing and replacement

Just like smoke alarms, carbon monoxide alarms don't last forever and require monthly testing and regular replacement.

At home, you must make sure that your carbon monoxide alarms are working. The best practice is to:

• Once a month, push the "Test" button to make sure the alarm is working,
• Once a year, replace the batteries to make sure your home has continuous protection, and
• Once every seven to 10 years, or as instructed by the manufacturer, replace the carbon monoxide alarm. Replacements must be labelled as meeting "CSA-6.19" or "UL 2034" safety standards.

In a rental, your landlord must make sure that there are working carbon monoxide alarms in the units. Renters should:

• Test the alarms in their unit once a month.
• Report any issues with the alarm to their landlord immediately.

Safety tips

With winter around the corner, we're closing our windows and turning on the heating systems in our homes. Alongside testing your carbon monoxide alarms, follow these safety tips to prevent a carbon monoxide-related emergency:

• Book an annual inspection and cleaning for:
  • Furnaces, chimneys and fireplaces
  • Gas dryers
  • Gas stoves
  • Any other fuel-burning appliances or equipment
• Shovel snow away from exhaust pipes, dryer vents, and intakes for fuel-burning appliances.
• Remove your vehicle from the garage immediately after starting it.
• Use generators or other gas equipment in a well-ventilated location outdoors away from windows, doors and vent openings.

Remember to:

• Never use gas appliances such as ranges, ovens, or clothes dryers to heat your home.
• Never use a barbeque or portable fuel-burning camping equipment inside unless it is specifically designed for use in an enclosed space.

For more fire safety tips and resources, visit Ottawa Fire Services' Fire safety, prevention and education page or contact the Fire Prevention and Education Team.

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