Carbon monoxide (CO) is a gas you can’t see, smell or taste. A CO alarm is how you find out it’s there. This guide covers what Health Canada says to look for, where to put the alarm, what to do when it sounds, and which models are currently top sellers on Amazon.
Quick picks
Affiliate links (paid links) below. Details
| Model | Good for | Where to buy |
|---|---|---|
| First Alert plug-in CO alarm with battery backup | A hallway outlet near bedrooms; mute and test button | Check price on Amazon |
| First Alert 10-year CO alarm with digital display | Seeing CO levels at a glance; no battery changes for ten years | Check price on Amazon |
| Kidde plug-in CO alarm with AA battery backup | A plug-in alarm with a test-hush button and peak level memory | Check price on Amazon |
What Health Canada says about CO alarms
Health Canada advises installing at least one carbon monoxide alarm with battery backup if you use combustion appliances or equipment at home, such as a furnace, fireplace, gas stove or fuel-powered generator. It says the most important place for an alarm is in hallways, outside of sleeping areas. It also advises testing your alarms regularly, replacing batteries as the manufacturer recommends, and writing the install and replacement dates on the battery or device. (Source: Health Canada, Carbon monoxide: Preventing exposure.)
Two more points from the same page are worth acting on. First, it suggests choosing an alarm with a digital display that shows low CO levels, which can help you catch problems early. Second, it says to buy alarms certified to Canadian safety standards: certification marks must be on the alarm and on the packaging, and if you buy online, buy only from sellers who can confirm the product is certified and bears a Canadian mark. Smoke alarms detect fire, not carbon monoxide.
Plug-in or battery?
- Plug-in with battery backup: plugs into a standard 120 V outlet with no mounting, and the backup battery keeps it working during a power outage. It matches Health Canada’s “battery backup” advice.
- Sealed battery model: no outlet needed, so it can sit on a shelf or mount on a wall. The model below uses sealed ten-year lithium batteries, so there are no battery changes during its life, but you still need to test it and note the replacement date.
If your CO alarm sounds
Health Canada’s steps are short: leave the home immediately and get to fresh air, don’t try to find the source, and once outside call 9-1-1 or the local fire department. Return only after a professional has fixed the problem. (Source: Health Canada, Carbon monoxide: Preventing exposure.)
Where CO comes from, and how to keep it out
Health Canada lists common sources as heating appliances such as a furnace, fireplaces and wood or pellet stoves, fuel-powered vehicles, gas stoves and dryers, camping stoves and barbecues, fuel-powered generators and equipment such as lawnmowers and snowblowers. Mild poisoning can feel like tiredness, headaches and shortness of breath; severe poisoning can cause loss of consciousness, coma and death. (Source: Health Canada, Infographic: Carbon monoxide.)
- Have fuel-burning appliances inspected by a professional at least once a year, or as the manufacturer instructs.
- Never idle a vehicle in the garage, even with the garage door open, and keep the door between the house and garage closed.
- Never run a fuel-burning generator indoors or in a garage or shed. Keep it at least 6 metres (20 feet) from buildings.
- After a snowstorm, check dryer, furnace and fireplace exhaust vents for ice, snow or debris.
- Electric heaters don’t burn fuel. If you’re choosing one, our space heater safety guide covers the features to look for.
Top-selling picks on Amazon
These show a top Best Sellers rank in Amazon’s Carbon Monoxide Detectors category (checked October 15, 2026). Rankings change daily, and the details below come from each product listing, so confirm them on the product page. Check that the alarm and its packaging carry a Canadian certification mark, as Health Canada advises, and ask the seller before buying if the listing doesn’t say.
First Alert plug-in carbon monoxide alarm with battery backup
- Listing describes an electrochemical CO sensor, a plug-in design for a standard 120 V outlet with no mounting, and a 9V backup battery.
- The listing says one mute button silences nuisance alarms and also tests the alarm, and the battery door opens from the front.
- Best for: a hallway outlet near the bedrooms.
First Alert 10-year carbon monoxide alarm with temperature and digital display
- Listing describes a backlit digital display that shows CO levels or room temperature, and a peak level feature that retrieves the highest CO concentration measured.
- Powered by sealed ten-year lithium batteries; the listing lists a 10-year limited warranty and tabletop or wall-mount placement.
- Best for: seeing CO levels at a glance, in line with Health Canada’s display advice, without battery changes.
Kidde plug-in carbon monoxide alarm with AA battery backup
- Listing describes a plug-in design for a standard 120 V outlet, a two-AA battery backup for power outages, and an 85-decibel alarm.
- Peak level memory records the last time CO was detected or when the unit was last tested, and a test-hush button tests the alarm or silences false alarms.
- Best for: a simple plug-in alarm with battery backup.
Before you buy
- Pick an alarm with battery backup, and check it is marked as certified to Canadian standards on the device and the packaging.
- Plan for the hallway outside the bedrooms first; if you can, add alarms on other floors with fuel-burning appliances.
- Test it when you install it and on a regular schedule, and write the install date on it.
- Check the expiry date and replace the alarm when the manufacturer says to.
- Looking at other indoor air tools? Our air purifier sizing guide covers Health Canada’s CADR rule.
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