Smoke Alarm Expiry Dates: The Codes Printed on the Back, and Which Alarms Are Already Past Them

Dates are the main event, but they are not the only thing the back of an alarm, or the alarm's voice, can tell you. The table below sorts the signs you are most likely to meet into three levels: replace now, fix today, and monitor.

Reading the chirps correctly

Chirp patterns are where many households get tripped up, because each brand speaks a slightly different language. On First Alert and BRK alarms, one chirp about once a minute means a low battery, three chirps mean a malfunction and five chirps mean end of life, according to First Alert's chirp troubleshooting guide. The end-of-life warning can be hushed for about two days, and after roughly two to three weeks it can no longer be silenced at all. First Alert also points out that pulling the battery or unplugging the alarm will not stop a low-battery chirp, and that dust and insects are a common cause of intermittent chirping.

Kidde uses a different code. On its 10-year sealed alarms, the end-of-life signal is an amber light blinking twice and two chirps every 60 seconds, while a low-battery warning is a single amber blink and a single chirp every 60 seconds. The end-of-life chirp can be quieted temporarily with the button but cannot be silenced after seven days. Universal's low-battery chirp comes a little more often, about every 40 seconds. So before you conclude that an alarm is "just the battery," count the chirps and check the brand.

Sealed 10-year alarms are a different conversation

A sealed 10-year alarm has a lithium battery that is built in and cannot be replaced. That is a convenience for a decade, and a firm instruction at the end of it: when a sealed alarm gives its end-of-life signal, the whole unit needs to come down. There is no battery drawer to open and no fresh cell that will fix it.

Kidde's sealed alarms also include a way to switch the battery off permanently before disposal, using a screwdriver to turn a red slotted arrow to the "permanently disable and discharge alarm" position until it clicks, according to its Kidde 20SD10 user guide. The same guide is refreshingly direct on two other signs in the table. Paint seals the vents and interferes with the sensor, so a painted alarm needs replacing, and if the alarm does not sound when tested, or sounds erratic or weak, the unit must be replaced.

The habits that keep a healthy alarm healthy between now and its replacement date are simple, and they are worth building into the same monthly routine as the test button.

Maintenance habits that keep smoke and CO alarms reliable lays out the cleaning, testing and battery routine month by month.

It helps to separate two things that often get blended together: what a manufacturer recommends, and what a provincial code or municipal bylaw requires. In several provinces, those two meet in the middle, because the code points back to the manufacturer's instructions. That makes the date on the back of your alarm more than good advice. In some places it is the trigger for a legal obligation.

Ontario

Ontario's Fire Code makes the connection explicit. Division B requires that smoke alarms be maintained in operating condition and that they be replaced within the time frame indicated in the manufacturer's instructions, as set out in the Ontario Fire Code's smoke alarm maintenance provisions. Because most manufacturers set that time frame at 10 years from the date of manufacture, an alarm past its date is out of step with the code, not just with best practice. The installation rules in Section 2.13 are a separate matter; they govern where alarms go and require them to meet the Canadian smoke alarm standard, CAN/ULC-S531.

The Office of the Fire Marshal's plain-language summary lines up with this. It states that every Ontario home must have a working smoke alarm on every storey and outside all sleeping areas, that homeowners are responsible for installing and maintaining them, and that "all smoke alarms wear out" and should be replaced every 10 years according to the manufacturer's instructions. According to the Government of Ontario's fire safety at home page, failing to comply with the smoke alarm requirements can bring a $360 ticket or a fine of up to $50,000 for individuals.

Renting in Ontario

For rental homes, the Fire Code treats the landlord as the owner. Landlords must give tenants a copy of the manufacturer's maintenance instructions, test alarms every year and after every change in tenancy, and keep them in working order, which includes replacing them on the manufacturer's schedule. Tenants, in turn, must tell the landlord as soon as they notice an alarm is disconnected, not working or impaired, and no one is permitted to disable an alarm.

That gives renters a useful role in the date check. If you find an alarm in your unit that is past 10 years, the right move is to let your landlord know in writing. In Toronto, the city's Toronto smoke alarm guidance explains that tenants whose landlord does not comply can call 311 for a referral to Toronto Fire Services, and a fire inspector will attend.

Quebec

Quebec's provincial guidance is the most direct statement anywhere in the country about where the clock starts. The Gouvernement du Québec's smoke detector page says smoke alarms must be replaced every 10 years from the date of manufacture and that all smoke detectors must meet Canadian standards and carry the ULC logo. In Montreal, the city bylaw makes building owners responsible for installing and maintaining alarms, with at least one per floor including the basement, while owners and tenants share the job of checking that they work.

Alberta and British Columbia

In Alberta, the City of Calgary's fire guidance keeps it simple: replace smoke alarms after ten years and look at the back of the alarm for the date of manufacture, as its Calgary smoke alarms page explains.

British Columbia's provincial guidance asks residents to get new smoke alarms every 10 years or according to the manufacturer's recommendations, and it offers a practical bonus for anyone clearing out an old unit. According to the Province of British Columbia's smoke alarm guidance, broken or expired alarms can be dropped off for free at more than 200 recycling locations across the province. In both provinces, local bylaws and your municipal fire department are the best places to confirm any additional requirements for rental properties.

Where sealed-battery alarms are required

A handful of cities go a step further and require sealed 10-year alarms in some homes. First Alert Canada's summary of those rules notes that Winnipeg has required them since 2016 in rental properties without hardwired alarms, Regina since January 1, 2020 on the same basis, and Montreal since a bylaw adopted June 26, 2019 for residences built before 1985 without hardwired alarms, according to its overview of 10-year smoke detector requirements. The company itself flags that this is its own interpretation, so check with your city before relying on it. What it does confirm is that in these homes, the end-of-life chirp means replacing the entire alarm.

While the alarm is off the ceiling and the model number is right in front of you, it takes only a moment to check it against Health Canada's recall database. The recall picture in Canada has changed in an interesting way. The notices that have landed most often in 2026 are not about ageing alarms from established brands. They are about new, uncertified alarms sold through online marketplaces.

Health Canada has been clear on the underlying rule for several years. Every hardwired and battery-operated smoke and CO alarm sold in Canada must be certified to Canadian standards, and its advisory on Canadian certification marks tells Canadians to immediately replace any smoke or CO alarm that does not carry a mark such as CSA, cUL, ULC or cETL.

In the spring of 2026, that rule turned into a steady run of warnings. Health Canada flagged PGST and GauTone photoelectric alarms, model PG-S11, sold through AliExpress in March. In April it added the Green Scenic smoke and CO alarm and the NestPulse WJ-SC05. In early May came two plug-in combination alarms sold on Amazon.ca under the same HD11 model number but different brand names: Gedsffati, with 3,588 units sold in Canada, and IQYEF, with 7,296 units sold. Each lacked a Canadian certification mark, and in each case Health Canada advised consumers to stop using the alarm, dispose of it according to municipal hazardous waste guidelines and replace it with a certified model.

The practical lesson for your date check is a comforting one. If your alarm carries a Canadian certification mark, a readable date inside 10 years and a model number that does not match a current notice, you can put it back up with confidence. If any of those three is missing, the alarm goes on your replacement list.

Health Canada's IQYEF disposal advisory explains how that case unfolded and what owners of HD11 alarms should do.

Carbon monoxide alarms and combination smoke-and-CO units deserve their own look, because their clock is not always the same as a smoke alarm's. Kidde advises replacing CO alarms every 7 to 10 years depending on the model, according to its guide on when to replace smoke and CO alarms, and First Alert likewise describes a typical 7-to-10-year life after first activation. That means a CO alarm can reach the end of its life a few years before a smoke alarm bought at the same time. Read the manual for your model, and if you no longer have it, look up the model number on the manufacturer's site before assuming you have the full decade.

A combination alarm follows whichever limit the manufacturer sets for the unit as a whole. Kidde's combination alarm manual, for example, recommends replacing the entire unit ten years from the date code on the back. When that alarm reaches its date, both your smoke protection and your CO protection in that spot go with it, so it is worth replacing it promptly rather than leaving it until the next convenient weekend.

It also helps to remember why CO alarms matter as a separate device. As Health Canada's guidance on preventing carbon monoxide exposure explains, carbon monoxide cannot be seen, smelled or tasted, and smoke alarms alert you to fires, not carbon monoxide. A smoke-only alarm, however new, does not cover that risk.

For Ontario households, replacing an expired CO or combination alarm is a natural moment to check placement too. Ontario's Fire Code changes in force since January 1, 2026 require CO alarms in existing homes with a fuel-burning appliance, a fireplace or an attached garage both next to each sleeping area and on every storey, as the Technical Standards and Safety Authority's summary of the new CO alarm rules explains.

Ontario's new CO alarm requirements for 2026 walks through which homes are covered and how many alarms a typical house now needs.

The most satisfying part of this job is the end of it. Picture a small list on the fridge or in your phone: every alarm in the house, the room it lives in, its brand, its manufacture date and the month it is due. It turns an easy-to-forget safety device into something you can see coming, the same way you might track a furnace filter or a car's next oil change.

As you replace older alarms, write the install date on the new ones, keep the manuals together in one folder, and set a reminder for the replacement month now rather than relying on a chirp years from now. If you are replacing several alarms at once, it is also a good moment to confirm you have one on every storey and near every sleeping area.

CO and smoke detector placement across Canada explains where each type of alarm belongs under Canadian standards, room by room.