We've all heard the annoying sound of a smoke alarm when a Sunday fry-up doesn't go to plan, frantically opening windows to make the beeping go away. Much like a smoke alarm, a carbon monoxide detector operates by alerting us of the presence of lethal gas, which is crucial to ensure the safety of any household.
When it comes to choosing the right detector, there's no room for error. For that reason, we've rounded up the best carbon monoxide detectors in terms of quality, longevity, and price.
Best carbon monoxide detector at a glance
But what causes carbon monoxide in the home? Appliances such as boilers, gas fires, central heating systems, and open fires can all lead to carbon monoxide exposure, where gas does not burn fully. If a household appliance, like a cooker or boiler, has not been installed or maintained adequately, this could lead to the presence of carbon monoxide. Camp stoves, charcoal grills, and burning fuels in an enclosed space can also lead to the build-up of carbon monoxide in your home.
Luckily, there are plenty of things you can do to prevent the release of carbon monoxide (CO), the main one being installing a carbon monoxide detector.
Remember, if your CO detector ever sounds, leave your house immediately and call 999.
How we tested these carbon monoxide detectors
Our Home, Pets and TV writer Arabella Horspool unboxed the following carbon monoxide detectors, placed the batteries in and used the 'Test' feature on the devices to simulate a real "alarm". She assessed the pitch and frequency of the alarms, and how clear the indicators were (e.g.: digital screens, lights etc.), as well as how easy they are to install and if they had any standout features or controls.
The best carbon monoxide detectors 2024
TESTED
A truly 'smart detector', this device uses a friendly human voice to give you an early warning of danger and tells you exactly where the danger is. It can connect to your phone, alerting you of a problem even when you're not home, and if carbon monoxide reaches dangerous levels, the alarm is sounded, along with pulsing red lights.
The Nest Protect performs tests on itself over 400 times a day so you don't have to, and even lights up every time you walk beneath it for some assistance en route to your midnight snack.
Tested by Yours.co.uk Editor Claire Tapley: "I'm really impressed with gadget. It's a smoke detector and carbon monoxide detector in one. I really like how it lights up when you walk past it. This is very helpful for nightly toilet trips as it means i don't need to put the lights on and wake everyone else up. I also really like the fact it can be controlled from my phone and shows me a timeline of all the events. It's very assuring that it tests itself up to 400 times a day so you don't need to.
It is more expensive than the other detector on this list but is well worth the extra money, especially if you already have other Nest gadgets as they can all be controlled from one app on your phone."
Pros
- Tells you what's wrong and where the problem is
- Phone alerts include for low-battery, smoke, carbon monoxide, sensor failure
- Detects smoke and carbon monoxide
- Battery powered not wired
Cons
- On the pricey side but worth the money
Tested
Upon opening the Kidde 5CO Battery Powered Carbon Monoxide Alarm, I felt like it was easy to use and I was correct. I slotted in the two batteries (which came with product) and it beeped once to - which was so loud that it made me jump - to indicate that it was on and working.
Then I slotted on the baseplate, pressed the 'TEST WEEKLY/RESET' button to give it a try and it the 'OPERATE' button lit up green, indicating that it was on. It does 4 beeps and then has a 5 second pause, before beeping again.
I like it's flexibility, as it can be mounted onto the wall with kit provided, or it can work just as well freestanding, making it ideal for taking with you on holiday if you want some peace of mind.
Unlike some of the options on the list, it doesn't have a digital screen, but this isn't necessarily needed as the light indicators are simple enough to understand.
Reviewed by Yours Commercial Content Writer, Arabella Horspool.
Pros
- Can be freestanding or wall-mounted
- Lifespan of 10 years for the sensor (reportedly)
Cons
- No digital screen
| Power source: | 2 AA batteries (supplied) |
Tested
Fireangel's multi-function carbon monoxide detector will provide audible and visual warnings of the early presence of CO in your home. The LCD display continuously measures levels of carbon monoxide and it also gives you humidity and temperature temperature readings which are an added bonus.
The 10-year lifespan means you don't need to worry about changing it every so often, and the quiet self-test will give you peace of mind about the effectiveness of the product. It's also portable, meaning you can take it with you to a holiday home etc..
Reviewed by Yours Commercial Content Writer, Arabella Horspool.
Pros
- Automatic self-diagnostic check
- Multi-function digital screen and room thermometer
- Large test and silence button
Cons
- Doesn't display all the functions at once - need to cycle through with the button
Tested
Not only is this device modern-looking and sleek, but it's also highly accurate and efficient. Designed in a way to give you the earliest possible warning of carbon monoxide presence, the X-Sense alarm will put your mind at rest. The unit is battery-operated, so there's no need to worry about playing around with wires or access to wall outlets, and measurements are taken every 10 seconds, clearly displayed on the large LCD display.
I put the batteries in and pressed the test button and boy, was it loud - It has such a loud and high frequency that I'd recommend it for large homes or businesses, as well as those that may be hard of hearing.
Reviewed by Yours Commercial Content Writer, Arabella Horspool.
Pros
- Low energy consumption
- Large LCD display
- Easy to set up
Cons
- Not made to be freestanding
Tested
With a seven-year lifespan, the Mercury alarm is a fantastic and reliable carbon monoxide detector. It's battery-operated, meaning it will still work during power cuts and provides clear, confident CO readings on the LCD display. The LED lights will beam green for power, amber for fault, and red for alarm, keeping you alert and informed at all times.
It has more of a high-pitched, faster beep than the other carbon monoxide alarms I tested. One thing that lets it down slightly in my eyes is that the base is quite loose, but that could just have been the one I tried that has this issue.
Pros
- LCD display with continual readout
- Tested in an approved lab
- Easy to set up
Cons
- Loose base plate
Carbon monoxide alarms we're currently testing
We're currently testing the carbon monoxide alarms listed below and will update this page with our findings. We still wanted to include them in this round-up as they have received some great reviews online.
Best twin pack
Credit: Argos Ensure the safety of your home by equipping it with a crucial defence against the 'silent killer,' carbon monoxide, with our reliable CO alarm. This twin pack is small and easy to use. It can be installed on a wall or ceiling for convenience.
Customer review: "I brought this as a replacement for my last Carbon monoxide alarm of the same model. The alarm I am replacing lasted seven years, so I am hopeful this will last as long."
Best carbon monoxide detector FAQs
Where should I install my CO detector?
Place your carbon monoxide detector high on the wall in any room that contains a fuel-burning appliance. You should also place a detector on every floor of your house in the hallways, close enough to bedrooms so that you can be alerted should the detector sound in the middle of the night.
How to prevent carbon monoxide poisoning
Prevention is key when it comes to carbon monoxide, and these are a few things that will help hinder the chance of exposure.
• Install battery-powered carbon monoxide detectors and place them in hallways close to bedrooms or spaces where people sleep. Make sure to change the batteries once or twice a year, and replace your CO detector every five years.
• Have appliances regularly serviced by qualified professionals.
• Make sure your chimney is swept thoroughly once a year.
• You should never burn charcoal inside your home.
• Never use a gas appliance that isn't properly vented.
• You should never use a generator in your home or within six metres of a window or vent.
What causes carbon monoxide in the home?
Carbon monoxide can result from fuel-burning appliances such as boilers, gas fires, heating systems, cookers, open fires, and water heaters.
How can you tell if there is carbon monoxide in your house?
Carbon monoxide is both odourless and colourless, meaning you can't see or smell it. This is part of what makes CO so dangerous and hard to detect. The best, most effective way to tell if there is carbon monoxide in your home is by installing a CO detector. Having said that, there are some tell-tale signs which might let you know that something is wrong. Things like heavy condensation in a room where there's an appliance or brown-yellow stains or soot around a fuel appliance are both signs of dangerous carbon monoxide levels.
If you have any concerns about CO exposure, leave your home and call the emergency gas number at 0800 111 999.
How does carbon monoxide affect the body?
According to the NHS, symptoms of mild carbon monoxide poisoning are as follows:
• Tension-type headache
• Dizziness
• Feeling and being sick
• Tiredness and confusion
• Flu-like symptoms
• Shortness of breath
• Stomach pain
If you have any concerns about CO exposure, leave your home and call the emergency gas number at 0800 111 999.
Eleanor Weaver is the Deputy Homes & Garden Product Editor for Yours, specialising in home décor, furnishings and appliances. Having worked commercially on Yours magazine and Yours.co.uk for the past six years, she's previously hosted Yours Live events and loves looking for home inspiration online.