Carbon Monoxide Alarms for Heating Season: The Every Storey Audit Ontario Homes Now Need

System care · Published 2026-11-10 · Last updated 2026-11-10

General information only. This audit covers alarms: counting, dating, placing, and testing them. Furnaces, boilers, fireplaces, and any other fuel-burning appliance belong to licensed technicians. If an alarm sounds, or anyone in the home feels unwell, leave first and call 9-1-1 from outside.

A beeping test button is not proof a home is covered. Since January 1, 2026, an Ontario home with a fuel-burning appliance, a fireplace, or an attached garage needs a working carbon monoxide alarm beside each sleeping area and on every storey, basement included (s1). A single alarm outside the bedrooms, the setup most homes settled for years ago, no longer meets the rule on its own. Heating season is when the gap matters, because the furnace starts running daily, windows stay shut, and over 65 percent of carbon monoxide injuries and deaths in Ontario happen in the home (s1).

Job summary: difficulty is low; this is a walk, a count, and a date check, not a renovation. Allow about an hour for a typical house, plus a shopping trip if floors or dates fail. Cost is the price of the missing or expired units only; a dated example sits in the cost section below. The hire a pro line is the appliances themselves: annual inspection and any repair of fuel-burning equipment is licensed work, and the audit ends wherever that work begins.

What changed on January 1, 2026

The trigger list is short. A home needs carbon monoxide alarms if it has a fuel-burning appliance such as a furnace, water heater, stove, or dryer, if it has a fireplace, if it has an attached garage, or, new in 2026, if it is heated by air from a fuel-burning appliance located outside the home, for example a unit in a utility shed (s1). Electric baseboard heat with no fireplace and no attached garage sits outside the list. Almost every other heated home in Ontario sits inside it.

The placement rule has two halves, and both must hold at once. First, an alarm adjacent to each sleeping area, meaning the hallway or area outside the bedrooms (s1). Second, an alarm on every storey of the home, including storeys with no sleeping areas at all (s1). The basement is the floor the 2026 change most often adds, followed by a main floor whose bedrooms are all upstairs. Installation requirements live in Section 2.16 of Division B of the Fire Code, O. Reg. 213/07 (s3).

One count catches people out. Adjacent to each sleeping area is counted per sleeping area group, not per floor. If bedrooms sit on the same floor but far apart, on opposite sides of a living room for example, that floor needs two alarms, one in the hallway outside each group of bedrooms (s2). A floor can therefore need two alarms while the floor below needs one, and the every storey rule is satisfied only when both counts are done separately and then added together.

Responsibility is assigned, not shared. In an owner occupied home, the homeowner is responsible for compliance (s3). In a rental home, the landlord is responsible for installing and maintaining the alarms (s3), and Ontario adds the testing detail: landlords test alarms annually, when the battery is replaced, when changes are made to the electrical circuit, and at a change of tenancy, and they provide the tenant with the alarm maintenance instructions (s1). Tenants carry one duty, notifying the landlord of any issue (s1). Removing batteries or tampering with an alarm is against the law (s1).

Read the dates before you count anything

An expired alarm that beeps on test is still an expired alarm. Carbon monoxide sensors wear out, and the City of Ottawa puts the service life plainly: replace the alarm every seven to 10 years, or according to the manufacturer instructions (s2). Every unit carries a manufacture or replace by date on its label; find it before trusting the unit. That date, not the test button, decides whether an existing alarm counts toward the totals above.

Buying replacements is a specification check, not a brand choice. Three points decide it:

• Certification mark. Look for the logo of a recognized standards testing agency, such as CSA, ULC, or ETL (s1). Ottawa names the marks CSA-6.19 or UL 2034 as the standards to look for (s2). A unit with no recognized mark does not go on the wall, whatever the packaging promises.
• Power type. Under the Fire Code, alarms may be hardwired, battery-operated, or plug-in devices (s1). Pick the type each location supports: plug-in where an outlet sits at a sensible spot, battery where it does not, and hardwired replacements where the home is already wired for them.
• Combined units count once, for both jobs. Many devices on the market combine a smoke alarm and a carbon monoxide alarm in one unit (s1). A combined unit satisfies one sleeping area or one storey position for both alarm types, and it carries one date to check, not two.

Height is the one placement worry to drop. Carbon monoxide is roughly the same weight as air and distributes evenly through a room, so alarms can be installed at any height (s3). What matters instead is that the alarm sits where it can be heard, and that the manufacturer instructions for that model are followed (s3).

Tools and materials

• A phone or notebook for the floor by floor count and the dates
• A step stool for reading dates on ceiling or high wall units
• Replacement alarms for any floor short a unit and any unit past its date, certification mark checked at the shelf
• Fresh batteries for any unit that takes replaceable batteries, unless it uses a sealed battery (s2)
• No tools for the appliances. Inspection of fuel-burning equipment is booked, not opened

The audit, in order

1. List the storeys. Write down every level of the home, basement and attic conversions included, then mark which levels hold sleeping areas. Success check: the list matches the house you walk, not the house on the listing; finished basements with a spare bed count as both a storey and a sleeping area.
2. Read every existing alarm date. Take each unit down or photograph the label, and record the replace by date beside its location. Any unit past its date, or with no readable date, goes on the replace list before any counting happens (s2). Success check: every alarm in the home has a date recorded, and none of the recorded dates has passed.
3. Count sleeping area coverage. Stand outside each group of bedrooms and confirm an alarm sits adjacent to it (s1). Split groups on one floor need one alarm each (s2). Success check: from any bedroom doorway, the nearest alarm is on the same floor and outside that group of rooms.
4. Count storey coverage. Walk floor by floor and confirm each storey has at least one alarm, including storeys with no bedrooms (s1). One alarm can serve both counts when it sits outside a sleeping area on its own storey; it cannot serve two storeys. Success check: every storey on the step 1 list has a unit, in date, on that storey.
5. Place the additions by audibility. Mount or plug in the missing units where they can be heard from the rooms they protect, following the manufacturer instructions for the model (s3). Success check: with bedroom doors in their normal nighttime position, each new alarm location is a place its sound will carry from.
6. Test every unit, old and new. Press the test button on each alarm; Ontario guidance is to test monthly this way (s1). Replace batteries in any unit that chirps or stays silent, and replace the unit if a fresh battery does not fix it. A chirping alarm may also have reached end of life, and the low battery warning, the end of life warning, and the emergency alarm are three different signals (s1). Success check: every unit sounds on test, and everyone in the home can tell the alarm sound apart from the smoke alarm sound, which differs (s1).
7. Teach the response once. If the alarm sounds for real: everyone leaves immediately and 9-1-1 is called from outside the building (s1). Success check: the youngest person in the home can say the first two moves without prompting.

What success looks like overall: a written list where every storey and every sleeping area group has an in date, certified, sounding alarm beside it, dated replacements on hand for anything that failed, and the appliance inspection booked. Anything less is a partial audit with the gaps named, which is still useful, provided nobody calls it done.

What one compliant refresh costs

Prices checked 2026-11-10. Costco.ca lists a Kidde plug-in carbon monoxide alarm with battery backup as a 3-pack at $68.99 (s4). That pack covers the common gap exactly: a basement, a main floor, and one sleeping area floor in a house that already has one working alarm can be brought to the every storey count with a single purchase, at roughly $23 per location before tax. The listing showed out of stock online at check time, so treat the figure as a current listed price reference and expect the shelf price at another retailer to land nearby rather than identical. Homes needing hardwired replacements, or needing five or six units, should budget per unit from that same per location figure and confirm the exact model price on the day.

The mistakes that undo the work

• Counting the house instead of the floors. Two alarms in a three storey house with a basement is one or two alarms short under the 2026 rule, however well placed they are (s1).
• Trusting the test button on an expired unit. The button tests the sounder and the circuit, not the remaining life of a sensor already past its seven to 10 year span (s2).
• Sealing the alarm instead of the problem. Pulling a battery to stop a chirp is tampering, and it is against the law (s1). The chirp is information: battery, or end of life (s1).
• Skipping the outside half of the season. The alarms warn; they do not prevent. Outside vents and chimneys for the furnace, dryer, stove, and fireplace must stay clear of snow and debris all winter, and fuel-burning appliances, chimneys, and vents need professional cleaning and inspection every year before cold weather (s1). Ottawa adds the garage line: never idle a car in the garage, even with the door open (s2), and never use a stove or oven to heat the home (s1).

When the audit ends in a phone call

Three findings close the audit and open a service call instead. An alarm that sounds with no test button involved means the response in step 7, not troubleshooting: out, then 9-1-1 from outside (s1). Symptoms in the household are the second finding. Carbon monoxide exposure can cause headaches, nausea, dizziness, confusion, drowsiness, and loss of consciousness (s1), and a pattern where people feel better outdoors and worse at home deserves the same outside call, not a wait and see evening. The third finding is the appliance side itself: a furnace overdue for its annual inspection, a blocked or snow buried vent that cannot be cleared safely from the ground, or any fuel-burning appliance behaving oddly. Those are licensed technician jobs (s1), and they are the reason the audit and the inspection belong in the same autumn week. Count the alarms, read the dates, book the inspection. The alarms are the warning system; the inspection is what gives them less to warn about.

, Tom Reilly, Home & DIY Writer