Product comparisons
Smoke and CO Alarms compared, with a verified Canadian price.
10 products verified · checked Oct 6, 2026
For a Canadian homeowner who's never sure whether an aging detector is still legal, or whose beeping unit just hit its 10-year expiry date. By Ontario Fire Code, every home needs a working smoke alarm on every storey and outside every sleeping area, and a working carbon monoxide (CO) alarm adjacent to every sleeping area if the home has a fuel-burning appliance, a fireplace, or an attached garage — a law named the Hawkins Gignac Act after a Woodstock, Ontario family who died of CO poisoning in 2008, in the same county this site already serves. The ten alarms below split into three groups: smart combination alarms that push an alert to your phone; interconnected alarms, wired or wireless, that all sound together without an app; and 10-year sealed-battery alarms and plug-in CO alarms you install once and mostly forget. Every row states exactly which certification mark — ULC, CSA, ETL, or only a US UL standard — was actually printed on the merchant's own page, never assumed.
Smart combination alarms — app alerts, voice, self-test
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| Product | Type | Sensor | Power | Smart features | Certification | Price | Our take |
|---|---|---|---|---|---|---|---|
First Alert SC5 Hardwire Smart Smoke & Carbon Monoxide Alarm First Alert | Combination smoke and CO alarm | Not stated as a specific type on this listing — product description names ionization and photoelectric generically, not tied to this exact model | Hardwired (120V) with battery backup | First Alert app push alerts, voice alerts naming the hazard and location, works with Google Home | not stated | Google's own named replacement for the discontinued Nest Protect — hardwired, app alerts, and voice warnings, though its own reviews are mixed on reliability. More+ Fits the existing Nest Protect ceiling mount and wiring harness, and is the replacement First Alert and Google both point Nest Protect owners to – 3.3 out of 5 stars on Amazon.ca with repeated verified-purchase reports of 3 a.m. false alarms that could not be silenced — read the reviews before buying three of these for every bedroom | |
Kidde Smart Smoke & CO Detector with Ring (RGCUAR-RW) Kidde | Combination smoke and CO alarm | Photoelectric (smoke) and electrochemical (CO) — stated directly on the listing | Hardwired (120V) with 2 AA battery backup | Ring app push alerts (no subscription needed for basic alerts); works with Alexa; optional $5/mo Ring monitoring | UL only | A hardwired combination alarm that reports to the Ring app without a subscription, built for a household already on Ring cameras or a doorbell. More+ Real-time Ring app alerts for every hardwired Kidde alarm in the house after adding just this one unit, no subscription required – Shipped from Amazon's US warehouse (import charges included in the price shown) and its own certification claim names only the US UL 217 standard, not a Canadian ULC or CSA mark | |
HEIMAN Smart Smoke Detector, Matter over Thread HEIMAN | Smoke alarm only — does not detect carbon monoxide | Dual-beam photoelectric | Battery (CR123A, included) | Matter over Thread — works with Apple Home, Google Home, Alexa, SmartThings, Home Assistant (requires a Thread Border Router hub) | UL only | A smoke-only (no CO) alarm that joins a Matter/Thread smart home directly, for a household already running Apple Home, Google Home, or Home Assistant. More+ The only alarm in this table that joins a Matter/Thread smart home directly, without a vendor's own cloud app or subscription – Smoke only, no carbon monoxide sensor, and several verified Canadian reviews report it failing to send any alert even once connected — treat it as a smart add-on to a real alarm, not your only one |
Prices and specs read directly from each merchant's Canadian product page on the date shown — never a guess. A product never appears here until we've verified it first-hand.
Interconnected alarms without a smart app — wireless or hardwired
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| Product | Type | Sensor | Power | Interconnect | Certification | Price | Our take |
|---|---|---|---|---|---|---|---|
Kidde Wire-Free Interconnect Smoke Detector (20SDR-VRF) Kidde | Smoke alarm only — does not detect carbon monoxide | Not stated as photoelectric or ionization on this listing — the spec table lists "Electrochemical," which is CO-sensor technology, on a device advertised only for smoke; treat that field as a likely listing error and confirm with Kidde before relying on it | 2 AA batteries (included), no wiring | Wireless — links up to 12 compatible Kidde alarms, no electrician needed | ETL | A battery-only smoke alarm that talks wirelessly to up to 12 other Kidde alarms — no app, no electrician, ideal for a renovation or a room with no existing wiring. More+ Links wirelessly with up to 12 other Kidde alarms with zero wiring — the easiest way to extend interconnected coverage into a basement or new room – Shipped from Amazon's US warehouse and its own spec table lists an inconsistent sensor type for a smoke-only device — confirm with Kidde's own documentation before buying | |
Kidde DETECT Photoelectric Smoke + CO Alarm, Hardwired (30CUAR-VCA) Kidde | Combination smoke and CO alarm | Photoelectric (smoke); CO sensor type not separately stated on this listing | Hardwired (120V) with 2 AA replaceable batteries — change every 6 months | Wired — when one alarm sounds, all connected units sound | not stated | A hardwired combination alarm with wired interconnect and replaceable AA backup batteries — Amazon.ca's #1 best seller in the category. More+ #1 best seller in its Amazon.ca category with 1,000+ bought in the past month and a 4.6-star rating across 38 ratings – Replaceable AA backup batteries need changing every 6 months, unlike the sealed 10-year units below — and several reviewers note the new wiring connector doesn't match older Kidde bases |
Prices and specs read directly from each merchant's Canadian product page on the date shown — never a guess. A product never appears here until we've verified it first-hand.
10-year sealed battery alarms and plug-in CO alarms
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| Product | Type | Sensor | Power | Lifespan | Certification | Price | Our take |
|---|---|---|---|---|---|---|---|
Kidde DETECT 10-Year Sealed Battery Smoke Alarm (P3010B-CA) Kidde | Smoke alarm only — does not detect carbon monoxide | Photoelectric | 10-year sealed lithium battery — no replacement batteries, ever | 10 years, sealed, then replace the whole unit | ULC | A Canadian-SKU smoke alarm with a sealed 10-year lithium battery and a voice warning — no battery changes, no low-battery chirps, ever. More+ The "-CA" model suffix and the listing's own certification claim both point to a Canadian-market SKU, with a sealed 10-year battery and no chirping battery changes – One verified reviewer (Liane Le Tendre) reports the mounting plate and screw spacing don't match older hardwired Kidde bases — confirm compatibility before replacing an existing hardwired unit | |
First Alert 10-Year Sealed Battery Combination Smoke & CO Alarm (SMCO210VA) First Alert | Combination smoke and CO alarm | Electrochemical (CO) and photoelectric (smoke) — stated directly on the listing | 10-year sealed battery — no replacement batteries, ever | 10 years, sealed, then replace the whole unit | ULC | A 2026-model combination alarm tested to the current Canadian smoke alarm standard, with bilingual voice alerts and a sealed 10-year battery. More+ Explicitly a "New 2026 model, rigorously tested to meet Canadian ULC 531 5th Edition alarm standards," with bilingual English/French voice alerts naming the hazard – Only one rating on Amazon.ca as of this check — too new to judge long-term reliability the way the higher-review-count alarms above can be | |
Kidde Combo Smoke + CO Alarm, Hardwired with 10-Year Sealed Battery Backup (30CUA10-VCA) Kidde | Combination smoke and CO alarm | Not separately stated for smoke vs. CO on this listing | Hardwired (120V) with 10-year sealed backup battery — no replacement batteries for 10 years | 10-year sealed backup battery, then replace the whole unit | ULC/CSA | A hardwired combination alarm whose backup battery is sealed for 10 years instead of swapped every 6 months — the listing names all three standards bodies at once. More+ The listing states it is "comprehensively tested and designed to UL/ULC/CSA standards" and the 10-year sealed backup ends the twice-a-year battery swap the plain hardwired model above needs – Costs about $14 more than the plain hardwired Kidde combo above for the sealed-battery upgrade — skip it if you don't mind changing AA batteries every 6 months | |
Kidde Plug-In Carbon Monoxide Alarm with Digital Display and AA Battery Backup Kidde | Carbon monoxide alarm only — does not detect smoke | Electrochemical | Plug-in (120V) with 2 AA battery backup | Not stated on this listing | UL only | The lowest-priced plug-in CO alarm in this table with a digital ppm display — #1 top-rated on Amazon.ca, though its own certification claim names only US standards. More+ #1 top rated on Amazon.ca at 4.8 stars across 1,269 ratings, and the cheapest plug-in digital-display CO alarm in this table – Shipped from Amazon's US warehouse and its own listing names only US UL 2034/UL217 standards — no ULC or CSA mark stated, so a Canadian inspector may not accept it on its own | |
First Alert Plug-In Carbon Monoxide Alarm with Digital Display (CO3-P01DA) First Alert | Carbon monoxide alarm only — does not detect smoke | Electrochemical | Plug-in (120V) with AA battery backup — change batteries roughly every 6 months | Not stated on this listing | CSA | A 2026-model plug-in CO alarm tested to the current Canadian CO alarm standard by name, with a digital peak-level display and AA battery backup. More+ Explicitly "New 2026 model, rigorously tested to meet Canadian CSA 6.19 2nd Edition alarm standards" — the only plug-in CO alarm in this table whose own listing names the Canadian standard by edition – No customer reviews yet on Amazon.ca as of this check — a newly listed model with no track record |
Prices and specs read directly from each merchant's Canadian product page on the date shown — never a guess. A product never appears here until we've verified it first-hand.
Also on Amazon.ca
A few things most owners of the systems above end up buying anyway — verified on Amazon.ca's own page, same rules as the table.
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Energizer Ultimate Lithium 9V Batteries (2-Pack)
A sealed 10-year alarm needs no battery at all, but every hardwired unit with a replaceable 9V backup, and every older stand-alone alarm, lasts years longer on lithium than on alkaline and won't leak and ruin the alarm.
CRC 2105 Smoke Test Brand Liquid Smoke Detector Tester
The alarm's own test button only checks the horn and circuitry, not whether the sensor can actually detect smoke — a real functional test needs an actual simulated-smoke spray like this one, done every few months.
Kidde Nighthawk Battery-Operated Carbon Monoxide Alarm (KN-COB-B-LP)
A furnace room or the wall next to an attached garage door needs its own CO alarm, not just the ones adjacent to bedrooms — this battery-only model needs no outlet and runs seven years on three AAs.
Reviewed by John Moelker
Founder, CompareLocal.ca · Oxford County, Ontario · Updated Oct 6, 2026 · How we choose
Near you: Woodstock, Stratford, St. Thomas — local water, utility and installer notes for safety.
How we chose
This category runs Amazon-first, same as the rest of this site: all ten alarms and all three consumables below link through Amazon.ca, where John earns a real commission once you buy (disclosed above every table). The Frizzlife LP365 also has a second link to Frizzlife's own Canadian store, which pays us a commission too. We opened each product's own Amazon.ca listing ourselves and read the price, sensor type, power source, and certification claim off it before it appears here — see each row's source for the exact page and date. Google discontinued the Nest Protect in 2025 and no longer sells it anywhere; rather than list a discontinued product with no real price, we checked Google's own support page and the press coverage of the discontinuation, which both point to the First Alert SC5 as the named replacement, and listed that instead. This is life-safety equipment, and we are not electricians or fire inspectors: we report exactly what each listing states about ULC, CSA, ETL, or UL certification, sensor type, and interconnect, and where a listing doesn't state something — or, in one case, states a spec that looks like a catalogue error — we say so plainly rather than guess. A row with no certification mark stated is not necessarily unsafe; it means the page we read didn't say, and you should look for the mark on the box itself, or ask the retailer, before you buy.
Already comparing basic gas and battery backup options for an outage? See portable power stations and basic gas generators we've already verified →
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Frequently asked questions
What does Ontario actually require, and what's the fine for not having an alarm?
By law, every home in Ontario — house, cottage, cabin, or apartment — must have a working smoke alarm on every storey and outside all sleeping areas; failing to comply with the Fire Code's smoke alarm requirements can mean a $360 ticket or a fine up to $50,000 for an individual and $100,000 for a corporation (ontario.ca/page/fire-safety-home). Separately, a CO alarm is required if the home has a fuel-burning appliance, a fireplace, or an attached garage, installed adjacent to each sleeping area — and, under a Fire Code change taking effect January 1, 2026, on every storey of the home too, even ones without a bedroom (ontario.ca/page/carbon-monoxide-safety). The CO requirement traces back to the Hawkins Gignac Act (Carbon Monoxide Safety), 2013, named for a Woodstock, Ontario family who died of CO poisoning in 2008 — the same county this site already serves with local vendor comparisons.
What's the real difference between a photoelectric and an ionization smoke sensor?
Ontario's own fire-safety page puts it plainly: ionization alarms tend to respond slightly faster to fast, flaming fires, while photoelectric alarms tend to be quicker at catching slow, smouldering fires — and the province recommends having both types in the home, or a dual-sensor unit, for the best coverage (ontario.ca/page/fire-safety-home). Several alarms in this table state their sensor type directly (photoelectric on the Kidde 10-year sealed units, electrochemical plus photoelectric on the First Alert 10-year combo); where a listing doesn't separately state the smoke-sensing technology, our table says so rather than guessing, since a few listings' own spec fields were inconsistent with the product description.
Why does interconnection matter, and do I need an electrician to get it?
In a two-storey farmhouse or a home with a finished basement, a fire or CO leak in one room may never be loud enough to wake someone two floors away — interconnection means every linked alarm sounds together the moment any one of them triggers, so nobody sleeps through a danger that started on another level. Wired interconnection needs an electrician to run the extra wire between units, which is straightforward if you're already replacing hardwired alarms on the same circuit. Wireless interconnection, like the Kidde 20SDR-VRF above, needs no wiring at all and links up to 12 compatible alarms by radio — the easiest way to add coverage to a basement, loft, or renovated room with no existing wiring run.
Will a smart smoke alarm actually alert me if nobody's home — at the cottage, or at the church building?
That's the whole point of the smart group above: a First Alert SC5 or Kidde Ring unit pushes a phone alert the moment it detects smoke or CO, even if nobody's inside to hear the horn — useful for a cottage left empty over a winter weekend, or a church building that sits unoccupied most weekdays. The tradeoff is dependence on the home's Wi-Fi or the unit's own app staying connected, and our own research turned up real complaints about both: a verified First Alert SC5 review describes repeated 3 a.m. false alarms the owner couldn't silence, and a verified HEIMAN Matter reviewer reports the unit showing as "online" in Google Home while sending zero actual alerts. A smart alarm is a useful second layer, not a substitute for the loud local horn every alarm in this table has regardless of connectivity.
How do I know if my current alarms are too old, and how often do I actually need to test them?
Test every smoke and CO alarm monthly using its test button, and replace the backup battery at least once a year, or whenever you hear a low-battery chirp — but the test button only checks the horn and the circuit, not whether the sensor itself still detects smoke or CO, which is what the tester spray in our consumables below is for. All smoke alarms wear out and must be replaced every 10 years per Ontario's Fire Code, full stop, regardless of how clean they test; CO alarms get replaced on the schedule stated in the manufacturer's own instructions, commonly 7 or 10 years depending on the model (ontario.ca/page/fire-safety-home, ontario.ca/page/carbon-monoxide-safety). If you don't know your alarm's install date, the safest assumption under Ontario's own guidance is that it needs replacing now.
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