New Ontario Carbon Monoxide Laws for 2026

What is a carbon monoxide detector?

A carbon monoxide (CO) detector is a vital safety device designed to monitor the air for carbon monoxide, a colourless, odourless, and poisonous gas produced by common fuel-burning appliances.

Because CO is entirely undetectable by human senses, these devices serve as a critical early warning system, identifying leaks from furnaces, stoves, or fireplaces. By sounding an alarm before CO reaches dangerous levels, they provide families with the life-saving time needed to evacuate and prevent serious illness or death.

The technology behind these devices relies on sophisticated sensors, such as electrochemical or metal oxide components, which constantly measure CO concentration in parts per million (ppm).

When the sensors detect that levels have risen above a safe threshold, the device triggers a loud, distinct alarm. This sound is specifically designed to be different from a standard smoke alarm, ensuring that occupants immediately recognize the specific threat and take the appropriate emergency actions.

Is it mandatory to have a carbon monoxide detector?

Yes, it is mandatory to have carbon monoxide (CO) alarms in Ontario, and the law has recently become much stricter.

As of January 1, 2026, the Ontario Fire Code was updated to expand the requirements for CO detectors. While the previous law only required alarms near sleeping areas, the new regulations require significantly more coverage.

To ensure your home meets the latest Ontario Fire Code standards, you are now legally required to install a working carbon monoxide alarm on every storey, including the basement and any floor without bedrooms.

Additionally, you must maintain a CO detector in the area immediately adjacent to all sleeping quarters, typically in the hallway outside the bedrooms.

The updated 2026 laws also mandate protection for homes heated by external fuel-burning appliances, such as outdoor wood boilers or furnaces located in detached sheds, making coverage essential for both resident safety and compliance with home insurance requirements.

Why do carbon monoxide detectors matter for your insurance?

From an insurance perspective, complying with the 2026 Ontario Fire Code is a fundamental element of smart risk management. Most home insurance policies are built on the expectation that you will maintain your property in accordance with local building and fire safety laws.

If a carbon monoxide incident occurs and an investigation reveals the home lacked mandatory detectors on every storey, it could complicate your claims process or even lead to a denial of coverage based on property maintenance failure.

For landlords, the stakes are even higher, as failing to meet these updated standards can result in significant legal liability and the potential loss of insurance protection in the event of tenant injury or death.

Implementing proactive safety measures not only protects lives but also offers peace of mind. This approach can significantly benefit you during premium reviews and policy renewals, as insurers prefer homeowners who actively reduce preventable hazards.

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Pro-tip: document your safety for your insurer

In the event of a claim, demonstrating compliance can expedite the process and safeguard your coverage. We recommend creating a safety folder (either digital or physical) that includes the following:

• Proof of purchase: Retain receipts for all carbon monoxide (CO) and smoke alarms, indicating the date of purchase and model information.
• Installation photos: Take photos of the alarms installed on each floor and near sleeping areas.
• Testing log: Maintain a simple sheet or digital note to record the date each month when you press the "test" button.
• Annual battery replacement: Document the date when you replace the batteries each year.

Who is responsible for carbon monoxide detectors on a rental property?

Under the Ontario Fire Code, building owners and landlords are primarily responsible for ensuring compliance with safety regulations. Building owners are strictly responsible for ensuring their properties meet all carbon monoxide alarm requirements.

In rental scenarios, landlords must take a proactive approach by installing and maintaining functional alarms in every unit. This duty includes testing the devices annually, as well as whenever a battery is replaced, the electrical circuit is modified, or a new tenant moves in. Furthermore, landlords are required to provide each tenant with a copy of the manufacturer’s maintenance instructions to ensure everyone is informed on how the units operate.

Tenants also play a vital role in maintaining a safe living environment. Their primary responsibility is to immediately notify the landlord if they become aware of any malfunctions or issues with the carbon monoxide alarms in their suite.

Safety is a collective effort, and the law is clear regarding interference: it is strictly illegal for anyone to remove batteries or tamper with these life-saving devices in any way.

Where to install carbon monoxide detecors

For those living in apartments or condominiums, the 2026 Ontario Fire Code mandates the installation of a carbon monoxide alarm if any of the following conditions are met:

• Fuel-burning features: Your specific unit contains a fireplace or any fuel-burning appliance (such as a gas stove or water heater).
• Proximity to service rooms: Your unit shares a wall, floor, or ceiling with a building service room that contains fuel-burning equipment.
• Proximity to parking garages: Your unit is located directly above, below, or adjacent to a parking garage.
• Shared heating systems: Your unit is heated by forced air originating from a fuel-burning appliance located elsewhere in the building, such as a central furnace room (a new requirement as of January 1, 2026).

To ensure full compliance and maximum safety, carbon monoxide alarms must be placed in the following specific locations within your unit and the building:

• Adjacent to sleeping areas: An alarm must be installed in the immediate hallway or area outside each bedroom.
• Every level of the home: You must have a working alarm on every storey of your unit, even on floors that do not contain sleeping areas (effective January 1, 2026).
• Heated public corridors: The building must have alarms installed in common hallways if those areas are heated by air from a fuel-burning appliance (effective January 1, 2026).

Carbon monoxide alarms requirements

To ensure your home is fully protected and compliant with the Ontario Fire Code, carbon monoxide alarms must be installed strictly in accordance with the manufacturer’s instructions.

The law provides flexibility in the type of device you choose, allowing for hardwired, battery-operated, or plug-in models. Many homeowners opt for combination units that integrate both smoke and carbon monoxide detection into a single device.

It is crucial, however, that everyone in your household learns to distinguish between the two; a CO alarm produces a distinct sound or alert pattern that differs from a standard smoke alarm.

When shopping for new devices, always verify that they meet Canadian performance standards. Look for the certification logo of a recognized testing agency, such as the Canadian Standards Association (CSA), Underwriters Laboratories of Canada (ULC), or Electrical Testing Laboratories (ETL), to ensure the unit is reliable.

Ongoing maintenance is just as important as the initial installation. To keep your family safe and maintain valid insurance coverage, it is essential to keep all alarms in peak operating condition.

This includes testing the devices monthly using the built-in test button, replacing batteries annually, and replacing the entire unit once it reaches the end of its lifespan, as indicated by the manufacturer.

Check your carbon monoxide alarms and insurance policy

Ensure your home is compliant with the new 2026 carbon monoxide detector laws by checking your alarms today; don't wait for an inspection or an emergency. While updating your safety measures, take a moment to compare home insurance quotes in Ontario for the new year.