verdict: Unresponsive to carbon monoxide – Don’t Buy

We have tested six alarms that look like the alarm pictured here between 2016 and 2018 and each has failed to detect the presence of carbon monoxide reliably in our tests. If the CO alarm in your home looks like the one shown, you will need to replace it because our tests prove that it’s likely to be unsafe. We’ve given alarms that look like this one our Don’t Buy warning, based on the six seemingly identical alarms that failed our CO tests.

Alarms that look like the one featured here may come with an unfamiliar brand name, or be unbranded, and the packaging can vary from alarm to alarm. But everything we’ve seen in the tests we’ve carried out on six alarms that look like this leads us to believe that they are the same products – and will regularly fail to detect carbon monoxide.We’ve tested six versions of this alarm that we bought for less than £10 from Amazon and eBay. Each of the alarms we tested, first in 2016 and then again in 2018, failed to reliably detect carbon monoxide. Because of this, we have made all alarms that share this design Don’t Buys.

Each alarm we’ve tested has come with instructions which wrongly advise consumers to not install the alarm in the kitchen, where in many UK homes you’ll find a gas boiler, which could be a potential source of carbon monoxide (CO).

 verdict: Failed to detect carbon monoxide three times in our tests

This carbon monoxide (CO) alarm failed to sound in one of our initial carbon monoxide detection tests and also failed to respond and sound the alarm in two later gas tests. Because of this, we’ve made it a Don’t Buy. It’s sometimes known as the JKD-512COM, and in other listings it’s unbranded. Our tests show that you can’t rely on it to detect carbon monoxide every time, so our advice is to give it a very wide berth. If you have one in your home, replace it as soon as possible with an alarm from a well-known brand, and buy from a high street store or reputable online retailer.

This unbranded carbon monoxide (CO) alarm failed to detect CO in three of our gas detection tests. The first failure was when we set it the challenge of detecting a potentially lethal, but low amount of the gas. Later failures were recorded when it failed to detect a huge concentration of the gas and then failed to detect a lower amount. The consequences of an alarm like this failing to sound in your home when you need it to don’t bear thinking about, and that’s why we’re making this dangerously unreliable alarm a Don’t Buy. Head over to our Best Buy carbon monoxide alarms to find the best alarm for you.

 verdict: Avoid this alarm – Don’t Buy.

This dangerous carbon monoxide (CO) alarm cannot be relied upon to detect CO and then sound the alarm when you need it to. That’s why we’re making it a Don’t Buy. It failed to detect CO in 17 of our detection tests and can’t be trusted to alert you if there’s a build-up of the deadly gas in your home. If you have this alarm, you should replace it as soon as possible with a model from a well-known brand.

This dangerous carbon monoxide (CO) alarm has failed 17 of our CO detection tests. What’s more, the instructions don’t meet the requirements of the carbon monoxide alarms standard, and when it does sound it’s too quiet. So, all things considered, this cheap and nasty alarm is the epitome of a Don’t Buy and should be avoided.

 verdict: Unreliable at detecting carbon monoxide – Don’t Buy

Bought from an online marketplace, this is yet another cheap and unbranded carbon monoxide (CO) alarm that you simply can’t rely on to detect CO. We’ve made it a Don’t Buy, as our test results show that after failing to detect CO three times, it’s more likely to endanger lives than to save them. If you have one in your home, replace it with an alarm from a well-known brand that’s available on the high street or from reputable online retailer.

This cheap, nasty and above all dangerous alarm failed to sound in three of our CO detection tests. The instructions give the wrong advice on where to site it, too. It failed to sound in the presence of a huge amount of CO and then failed to recover and sound with a lower concentration of the gas. And in our 90 day test, where the alarm is tested on day one of testing and again on day 90, we found that it again failed to detect the gas. If our test results are mirrored in your home, this alarm would simply fail to detect CO reliably enough. That’s why we’ve made it a Don’t Buy and are warning consumers about it.

 verdict: Excellent

The Lifesaver Carbon Monoxide Alarm 5CO comes with replaceable batteries that you’ll need to change every two to three years during its seven-year lifetime. In return for this upkeep, you’d expect to be able to rely on the Lifesaver Carbon Monoxide Alarm to live up to its reassuring name. To find out if this trust is justified, we tested it back in 2016 against four different levels of the poisonous gas in our test lab. Read on for the results of our test of this Lifesaver carbon monoxide alarm.

This reliable and loud carbon monoxide alarm did brilliantly in our tests, which is why it’s a Best Buy. It detected all levels of carbon monoxide in our 30+ lab tests, it recovered well to sound again following exposure to a huge amount of the gas and it was just as effective at the end of our three months of testing as it was on day one. So, don’t let the fact that it’s a few years old now get in the way of you buying an excellent carbon monoxide alarm.

 verdict: Dangerously unreliable – Don’t Buy

This unbelievably dangerous carbon monoxide (CO) alarm failed to detect the deadly gas in every single one of our 38 tests. That’s why we’re making it a Don’t Buy. We bought it from eBay, but it’s also available from other online marketplaces. If you have an alarm that looks like this in your home, your best course of action is to replace it with an alarm from a well-known brand that you buy from a high street shop or reputable online retailer.

This alarm simply can’t detect carbon monoxide (CO) and should be avoided. In our tests it failed to detect the gas every single time and that’s why we have made it a Don’t Buy. And like many of the other alarms that we bought from online marketplaces, the instructions are misleading and potentially dangerous. So, ignore the cheap price and don’t buy this dangerously unresponsive alarm.

 verdict: Dangerously unresponsive – Don’t Buy

This unsafe carbon monoxide (CO) alarm failed to detect the deadly gas in all but one of our tests – registering 37 failures to detect CO and sound the alarm – so we’re making it a Don’t Buy. We bought it from eBay, but it’s available from other online marketplaces too. In common with a collection of other cheap and unbranded alarms that we have bought and tested through this kind of site, you simply can’t rely on it to detect carbon monoxide when you need it to. If you have an alarm that looks like this in your home, replace it with a well-known brand from a high street store or reputable online retailer. 

This is yet another unresponsive and downright unsafe carbon monoxide (CO) alarm that we bought from an online marketplace. It failed all but one of our CO detection tests, so in your home you just wouldn’t be able to trust it to alert you about a potentially deadly build-up of the gas. It’s far too quiet when it does sound and the instructions are potentially misleading. This alarm is one of the more worrying and dangerous products that we’ve tested, because of this we’ve made it a Don’t Buy and we would strongly advise you against buying it.

 verdict: Very good indeed

You’ll need to replace the batteries in the Kidde Carbon Monoxide Alarm 7CO every two to three years, but in return it promises a decade of faithful service. So, is this 2016 carbon monoxide detector a worthwhile investment? We tested its ability to alert you to the presence of carbon monoxide in a series of exacting tests, and assessed the clarity of its alarm and installation instructions. Check our results to discover if this carbon monoxide detector has what it takes to be a Best Buy alarm.

This brilliant carbon monoxide alarm passed all 30+ gas detection tests we set it, including detecting low, middling and high levels of the gas. It was loud enough to wake the whole house and we liked the fact that it was just as good at detecting carbon monoxide on day 90 of our tests as it was on day one. All in all, a clear Best Buy and one for your shortlist despite its advancing years.

 verdict: Dangerously unresponsive – Don’t Buy

This a Don’t Buy carbon monoxide alarm and it should be avoided. In our tests it failed to detect the deadly gas a worrying 27 times. It doubles as a <a href=”https://www.which.co.uk/reviews/smoke-alarms/unbranded-smoke-alarm-in-blue-box”>smoke alarm</a> and it was just as bad when we tested its smoke detection abilities. We bought it from a seller on eBay, but you’ll also find it listed on other similar online marketplaces. If you have one in your home, replace it with a well-known brand from the high street or a reputable online site.

This alarm is one of the more dangerous products we’ve ever tested. It’s both a carbon monoxide detector and a smoke alarm, and in the past year we’ve tested it in both modes. As a smoke alarm, it failed to sound in any of our eight smoke detection tests. And in our CO detection tests it failed to sound in 27 of our 38 CO detection tests and even when it does sound, it’s far too quiet. It’s one of the most obvious Don’t Buys we’ve seen and it’s one to avoid.

 verdict: Failed to detect CO every time – Don’t Buy

The X-Sense CO03D carbon monoxide alarm failed to sound in one of our carbon monoxide tests when we tested it in 2018. Because of the safety concerns we have based on the gas detection failure in our tests, we’ve made this X-Sense alarm a Don’t Buy. This product failed to sound when in the presence of a catastrophic concentration of carbon monoxide and all three of the samples of alarm we tested failed in the same way.&nbsp;

This alarm did a good job in almost all of our carbon monoxide detection tests, but due to it not being able to detect CO when exposed to a huge amount of the killer gas, we’ve made it a Don’t Buy. Your best bet is to pass on this model and to go for a Best Buy carbon monoxide alarm instead.

 verdict: An excellent alarm

The FireAngel CO-9B Carbon Monoxide Alarm will last for seven years before you need to replace it, although you’ll need to change the batteries once or twice during its lifetime. It may need a touch more maintenance than some other carbon monoxide detectors, but does it reward your efforts with effective carbon monoxide detection? We tested it back in 2016, so read on for our test results.

This excellent carbon monoxide alarm might be advancing in years, but it did a great job of detecting the gas in our tests. It’s a worthy Best Buy and you’ll have no problems hearing it when it sounds. We also liked how well it recovered from being exposed to a catastrophic amount of carbon monoxide, as it continued to work reliably even after such an event.

 verdict: Recommended

The FireAngel CO-9D Carbon Monoxide Alarm has a sealed battery, which means you’ll never have to buy replacements during its seven-year lifetime. It sounds like a convenient buy, but does it deliver where it really matters? To find out if you can trust this 2016 carbon monoxide detector when you need it most , we tested its reactions to different levels of carbon monoxide in a series of stringent safety tests.

This carbon monoxide alarm might be a few years old now – we tested it back in 2016 – but we still have no hesitation recommending it to you. It sailed through all of our gas tests and detected carbon monoxide every time we set it the challenge. It’s a product that we think you can rely on and is therefore a Best Buy model that we would recommend.

 verdict: A very good alarm

If you buy the FireAngel CO-9X-10T-FF Carbon Monoxide Alarm you won’t need to replace it for a whole decade, which is about the top end of any carbon monoxide detector we’ve seen. It’s certainly long-lasting, but is it actually any good at sniffing out the deadly gas? We tested this FireAngel carbon monoxide detector back in 2016 to find out. Read on for the results of our carbon monoxide gas detection tests.

This is a long-lasting carbon monoxide alarm that our test results show you can rely on. It’s up to the task of detecting both high and low levels of the deadly gas, it recovers admirably from exposure to super-high concentrations of carbon monoxide and you won’t have any problems hearing it when it goes off.

 verdict: Excellent in our tests

If you’re looking for a device that needs minimal maintenance, then the FireAngel CO-9X Carbon Monoxide Alarm may well catch your eye. It has a sealed battery, which means you won’t have to replace the batteries during its seven-year lifetime. We’ve tested its detection of killer carbon monoxide in a series of stringent lab tests back in 2016 to see if it pairs convenience with the quick reactions you need to keep you and your family safe in an emergency. Read on for the results of our tests.

This excellent carbon monoxide alarm passed all of the 30+ gas tests it was faced with, sounding its alarm at the right time every single time. It has a loud alarm, and is robust and reliable. It was as sensitive to the threat of CO on day 90 of our tests as it was on day one and all of this makes it a worthy Best Buy. It might be a little long in the tooth now – we tested it back in 2016 – but it’s still one of the best carbon monoxide alarms we’ve seen, so don’t allow age to be a barrier.

 verdict: Imperfect in our tests

The Aico Ei208 carbon monoxide alarm failed to sound in one of our 2018 carbon monoxide tests and that’s why we’ve made it a Don’t Buy. In one of our tests, we flooded three of the Aico alarms with a catastrophic level of carbon monoxide to which they responded correctly and sounded. But later, when we tested them with a lower but still dangerous level of the gas, none of the three alarms sounded. Aico told us that it’s concerned, that it takes all matters of alarm quality and reliability very seriously, that all of its alarms are independently tested, it hasn’t had a problem with these alarms since they were launched in 2010, and that it is confident its alarms meet the carbon monoxide alarms standard.

This Aico alarm failed one of our carbon monoxide detection tests and we have made it a Don’t Buy because of this failure. It passed all of our other carbon monoxide detection tests, but it was unable to recover and continue to sound reliably after exposure to a very high concentration of carbon monoxide.

 verdict: First-class

The clue is in the name of the Kidde Long Life Carbon Monoxide Alarm 10LLCO – it should last up to 10 years before you’ll need to replace it. Along the way you won’t even need to replace the batteries, which are safely sealed inside the unit. But does it pair this long life with the ability to detect even small concentrations of carbon monoxide in the air? We put the Kidde carbon monoxide detector through a series of gas detection tests back in 2016 to find out.

This Kidde carbon monoxide alarm did a first-class job of detecting the deadly gas in our lab when we tested it in 2016. And even after being presented with catastrophic levels of carbon monoxide, it recovered well to carry on working reliably. It’s as loud as an alarm needs to be, and its 10-year lifespan is impressive, too.

 verdict: Truly outstanding

The Nest Protect Smoke + CO Alarm can send alerts about dangerous levels of carbon monoxide or smoke direct to your smartphone, which is a handy touch if you’re out of the house at the time. This more advanced two-in-one functionality, along with its 10-year lifespan, pushes the price up far above the price of a standard CO alarm. This review is of how well the Nest detects CO, but it’s also a smoke alarm and since testing it, the law on smoke alarms has changed in Scotland. This means that as the Nest doesn’t come with a heat detection function, it won’t be suitable for Scottish homes from 2022. We put the Nest Protect Smoke + CO Alarm through a series of stringent carbon monoxide safety detection tests to find out how well it detects the deadly gas. Read on for the results of our tests.

An innovative product that worked brilliantly as a carbon monoxide alarm in our tests. The alarm sounded exactly when it was meant to and a message was received by our smartphone around 30 seconds later. It’s loud enough and was as good at detecting the gas on day 90 of our tests as it was on day one. It’s also a Best Buy as a smoke detector, but from 2022, due to a change in Scottish law, it won’t be suitable for homes in Scotland as one.

 verdict: Responsive and impressive

Offering a market-leading 10-year lifetime, the FireAngel W2-CO-10XQ promises a full decade of service before you need to replace it. Does it pair this long life with a first-class ability to detect poisonous gas? To find out we put this carbon monoxide alarm through a full range of safety tests back in 2016, assessing everything from the clarity of its alarm sound to how sensitive it is to four different levels of carbon monoxide. Read on for our summary of how this FireAngel carbon monoxide alarm fared in our lab tests.

This effective carbon monoxide alarm passed every single one of the 30+ gas tests we put it through and it was just as good at detecting CO 90 days into our testing as it was on day one. It’s loud enough for everyone to hear and we’re delighted to add it the list of Best Buy alarms that we recommend. So, don’t worry about this alarm being a few years old – it might be getting on a bit but it’s still one that we’d recommend to you.

 verdict: An excellent alarm

The Kidde 4MCO mains-powered carbon monoxide (CO) alarm is designed to last for seven years before it will need to be replaced. It comes with a rechargeable backup battery so that it will sound even during a power cut. A test button allows you to check it’s working and the alarm chirps to let you know when it reaches the end of its life. It can be connected to other Kidde alarms so that if one detects danger, they will all sound. We tested the Kidde 4MCO – the 4MDCO is identical other than it has a digital display. We tested the Kidde 4MCO back in 2019 to find out how well it detected a variety of concentrations of carbon monoxide. Read on for our verdict on this mains-powered carbon monoxide alarm and to find out whether this is the right alarm for you.

This excellent and dependable carbon monoxide (CO) alarm was outstanding at detecting the deadly gas in our tests. We tested it with concentrations of carbon monoxide from 30 parts to million (PPM), where an alarm shouldn’t sound right through to a catastrophically high concentration of 5,000ppm. In each case this Kidde alarm was superb at detecting the gas and sounding the alarm in good time. It was easily loud enough too, and a worthy Best Buy even if it is a few years old now.

verdict: Very impressive

The mains-powered Ei Electronics Ei3018 carbon monoxide alarm is built to detect CO for five years and has a warranty to cover this. There is a backup rechargeable battery, which kicks in if there’s a power cut. The alarm can be used in a network of other Aico/Ei alarms, so that if one detects danger, they all sound. You’ll need the Ei3000MRF interlink module (£48) to do this, which also sends data to your smartphone regarding when it detects CO. To find out how well this Ei Electronics mains-powered CO alarm detects the deadly gas, we tested it in 2019. Read on for our verdict on this alarm.

This is an outstanding mains-powered Best Buy CO alarm. It was excellent at detecting the gas and sounding the alarm in all our CO gas detection tests. It was well able to detect CO and raise the alarm whether being tested with low or high concentrations of the gas. It continued to detect reliably after being drenched with an ultra-high amount of the gas. It was as dependable on day 90 of our tests as on day one, and was more than loud enough.

 verdict: A very good CO alarm

The Honeywell XC100 carbon monoxide alarm is built with longevity in mind. It comes with a sealed-in and tamper-proof 10-year battery, so you won’t need to worry about finding replacement batteries for it. It also comes with a backlit warning message in red, which shows through the case. When there’s CO in the air, the Honeywell not only sounds, but also displays the message ‘Alarm evacuate’. But how well does it detect carbon monoxide? To find out, we tested it back in 2018. Read on for the full results.

This might be a little long in the tooth but it’s still a very good carbon monoxide alarm. We challenged it to detect CO at a range of concentrations, from very low levels where the alarm isn’t required to sound right up to catastrophic levels and everything in between. In all of our tests this superb alarm triggered when it needed to, it was loud enough and it was as good after three months as it was on day one. And that’s why it’s a Best Buy.