CO Detector Placement Ontario 2026: Hawkins-Gignac Act, One-per-Level Rule, and Where to Actually Install Them

The Hawkins-Gignac Act, in Plain English

In December 2008, Laurie Hawkins, her husband Richard, and their two children died of carbon monoxide poisoning in their Woodstock home. A blocked vent on the gas fireplace sent CO into the house overnight. There was no CO alarm. Laurie's uncle, OPP officer John Gignac, spent the next five years lobbying for a law that would put CO alarms in every Ontario home with a fuel-burning appliance.

The result was Bill 77, the Hawkins-Gignac Act, passed in November 2013. It amended the Fire Protection and Prevention Act and authorized Ontario Regulation 194/14, which folded CO alarm requirements into the Ontario Fire Code effective October 15, 2014.[2] The 2014 rule was straightforward: one working CO alarm adjacent to each sleeping area in any residence with a fuel-burning appliance, a fireplace, or an attached garage. That is the baseline that has been enforceable through local fire services for more than a decade.

The Hawkins-Gignac Foundation still operates as a public education charity funded by CO alarm manufacturers and the gas industry, and its materials remain the best plain- language explanation of the law from the family that pushed it through.[1]

The One-per-Level Rule (2026 Amendment)

On January 1, 2026, the Ontario Fire Code was amended again. The sleeping-area rule still stands, but now you also need a CO alarm on every storey of a residence that has a fuel-burning appliance, attached garage, or fireplace. "Every storey" includes storeys that do not have sleeping areas: finished basements, furnace rooms, unfinished attics used as storage, upper floors with only a den or office.[4] The Office of the Fire Marshal publishes the plain-English version of the current rule on Ontario.ca, which is where most homeowners and landlords are going to run into the requirement.[3]

Practically, in a three-storey townhouse with a gas furnace in the basement and bedrooms on the top floor, you now need three alarms minimum: one in the basement (because the furnace is there), one on the main floor (because it is a storey), and one in the hallway outside the bedrooms (because it is adjacent to sleeping areas). A detached bungalow with a finished basement and no garage needs two: one outside the bedrooms and one in the basement.

The rule is retroactive. Existing homes are expected to comply as of January 1, 2026, not just new builds. Ontario Fire Services do not proactively inspect every house, but non-compliance can surface at the worst possible moment: during an insurance claim after a fire, during a home sale inspection, or during a routine rental unit inspection.

The "Outside Every Sleeping Area" Rule

The sleeping-area requirement has not changed and it is the most important one, because CO alarms only save lives if they wake you up. Install a CO alarm in the hallway or common area directly outside each set of bedrooms. In a typical two-storey home with bedrooms upstairs, that means one alarm in the upstairs hallway between the bedrooms.

If your home has bedrooms on multiple floors (a finished basement guest room plus upstairs bedrooms, or a main-floor primary with secondary bedrooms above), each sleeping area needs its own nearby alarm. An alarm in the basement hallway does not satisfy the upstairs sleeping-area requirement and vice versa.

The sleeping-area alarm should be mounted according to the manufacturer's instructions, usually on a wall 150 mm (6 inches) below the ceiling or on the ceiling itself, in a location that is not blocked by furniture, curtains, or a closed bedroom door. Do not tuck it inside a bedroom behind a door that gets closed at night. The whole point is that the hallway alarm reaches every sleeper through open bedroom doorways.

The 5-Metre Rule for Fuel-Burning Appliances

The single most common reason a CO alarm nuisance-trips is that it was installed too close to the furnace, the water heater, or the gas range. Most Canadian-certified alarms specify a minimum of 4.5 to 5 metres horizontally from any fuel-burning appliance.[6] Within 5 metres, the brief CO spike that occurs when a burner first ignites (before the flame fully stabilizes and the draft establishes) can push the sensor above its alarm threshold, even though the appliance is working exactly as designed.

In a tight furnace room, 5 metres is often impossible. That is fine: the Fire Code says the alarm goes on the storey, not specifically next to the furnace. Mount it in the adjacent hallway or the room that opens off the furnace room rather than directly above the burner. First Alert's Canadian product documentation and Kidde's equivalent both list this clearance as the primary cause of nuisance tripping, and both manufacturers recommend mounting the alarm on a wall in an adjacent space if the mechanical room is too small to accommodate the 5-metre offset.[7]

The 5-metre rule also applies to gas ranges, wood stoves, gas fireplaces, and pellet stoves. If your combination smoke-and-CO alarm is in an open-concept kitchen right above the gas range, expect it to nuisance-trip when you sear a steak with the hood fan off.

Hardwired vs Battery vs Plug-In

The Fire Code permits all three power types and all three can be legal if they carry a Canadian certification mark (CSA, ULC, or ETL).[3] Each has a different practical case.

Hardwired

Hardwired alarms are wired into the electrical system with a 9-volt battery backup. They are the standard in new construction because they can be interconnected: when one alarm detects CO, they all sound. Interconnection is a real safety feature in a multi-storey house because a basement furnace-room trip wakes the bedrooms upstairs immediately, not after CO has already spread to the second floor. A licensed electrician installs a hardwired alarm in a new box for roughly $80 to $150 per location if the wiring is accessible. Full-house retrofits with new wiring are expensive; most homeowners pick hardwired only where ceiling boxes already exist.

Battery-Only

Battery alarms are $25 to $60 for a combination smoke-and-CO unit and install in minutes with two drywall anchors. Newer units have sealed lithium batteries rated for the full 7-to- 10-year life of the sensor, so you never change the battery: the whole unit gets replaced at end-of-life. For existing Ontario homes being brought up to the 2026 one-per-storey rule, battery combos are usually the fastest and cheapest path to compliance.

Plug-In

Plug-in alarms with battery backup plug into a standard outlet and are useful where there is no ceiling box and mounting on a wall with an outlet makes sense (finished basements, rental suites). The downside is that they occupy an outlet, a toddler or a vacuum cord can unplug them, and they cannot be mounted at the optimum height (ceiling or high on a wall) unless the outlet happens to be up there.

Combination Smoke and CO

A single combo unit handles both Fire Code smoke alarm requirements and CO alarm requirements. For a retrofit, combo units cost roughly the same as a CO-only alarm and eliminate a second device on the ceiling. Make sure the unit is labelled as meeting both CSA 6.19 (CO) and ULC S531 (smoke) standards, and has a Canadian certification mark visible on the back or the packaging.

Sensor Life and the 7-to-10-Year Replacement Rule

An electrochemical CO sensor is a wet-cell electrochemical reaction. The electrolyte slowly degrades and the sensor becomes progressively less sensitive over the years, whether the alarm has ever gone off or not. Canadian-certified CO alarms carry a manufacturer's expiry of 7 to 10 years, and that expiry is printed on the back of the unit, not the packaging.

If you pull an alarm out of a clearance bin, the relevant date is the date of manufacture, not the date of purchase. A unit stamped "Manufactured 2018" is in its final year in 2026, regardless of whether it was installed in 2023. Most post-2013 alarms emit a distinct end-of-life chirp (typically a different pattern from the low-battery chirp) so you cannot simply swap the battery and keep going.

The cheapest approach is to buy sealed-battery combo units and replace the whole unit at its end-of-life date. For a typical Ontario home, that is four or five units on a 7-to- 10-year rotation: call it $30 to $50 per unit on average, amortized across the decade. It is the best safety spend in the house.

Nuisance Alarms vs Real Alarms

A real CO alarm in Ontario is a distinct pattern: four rapid beeps, a pause, four rapid beeps, repeating. That pattern is the standard across all Canadian-certified alarms and means CO has exceeded a threshold (usually 70 ppm for an hour, or higher levels for shorter periods). If you hear it, get everyone outside, call 911 or the gas utility from outside the house, and do not go back in until the fire service confirms it is safe.

A nuisance alarm is a real reading of CO that briefly exceeded the threshold but was not sustained at a dangerous level. Common causes: a cold-start furnace that burned slightly rich for 30 seconds before the draft stabilized; a car left running for a minute in an attached garage; a burst of backdraft from a fireplace when the chimney was cold. The alarm is working correctly; the location is borderline. Silence the alarm, check for an obvious source (running vehicle, blocked chimney), and move the alarm farther from the appliance if nuisance trips repeat.

Repeated nuisance alarms at the same location are a signal, not a false positive. If the alarm is already 5 metres from the furnace and still trips, call a TSSA-registered gas technician to inspect the appliance. A cracked heat exchanger, blocked vent, or undersized combustion air intake can all produce a real but intermittent CO leak.[4] That is what the alarm is designed to catch, and it is what the Hawkins family did not have in 2008.

Test Schedule

The Fire Code requires that CO alarms be maintained in operating condition, which means monthly testing and replacement at end-of-life. A realistic Ontario homeowner schedule:

• Monthly: press the test button on every alarm. A tested alarm chirps and then confirms it is operational. A dead alarm does not chirp at all.
• Annually: replace the 9-volt backup battery in any hardwired or non-sealed battery unit (daylight saving time is the traditional reminder). Vacuum dust off the face of the alarm.
• Every 7 to 10 years: replace the entire alarm at its expiry date. Write the replacement date on the side of the alarm with a Sharpie when you install it.
• After any trip: check the alarm's memory feature (most models) to see the peak ppm reading. If it was a nuisance trip, consider whether the alarm is too close to a fuel-burning appliance. If it was a real trip, have the appliance inspected before anyone sleeps in the house again.

TSSA and the Underlying Appliance

CO alarm compliance sits with the Office of the Fire Marshal and local fire services. TSSA regulates the fuel-burning appliance: the furnace, water heater, gas range, gas fireplace, or propane tank that can actually produce CO.[4] The two systems interact in one important way: when a CO alarm trips repeatedly, the fix is almost never a new alarm. It is a TSSA-registered technician inspecting the appliance.

If a gas tech finds a cracked heat exchanger, a disconnected vent, or a failed draft inducer, they are required to red-tag the appliance, shut off the gas, and refuse to re-energize it until the fault is repaired. That is the enforcement path that closes the loop: Fire Code puts the alarm in your house, the alarm catches the leak, TSSA deals with the appliance. Homeowners who ignore a repeating alarm because "it is probably just the furnace starting up" are the ones who find out the hard way that it was not.

Related Guides

• Ontario CO Alarm Rules 2026: What Changed and What You Need
• Furnace Noise Troubleshooting Ontario
• HVAC Consumer Protection Ontario

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