Do not install CO alarms within 3 metres of doors or windows, above radiators, or immediately close to anything that gives off steam or fumes like a cooker or shower room. Similarly, it is not recommended to install detectors in dusty areas such as workshops or garages. The best carbon monoxide detector should be built with an electrochemical sensor that constantly measures the levels of carbon monoxide in the air, letting off a loud audible alarm should levels become too high. Combined smoke & CO alarms or mains-powered CO alarms are typically installed on the ceiling and should be at least 30cm away from any wall, light fitting, or other obstruction.

The Nest Protect is very easy to set up: simply remove the battery tab, launch the app, log in to your Wi-Fi, give it a name (kitchen, lounge and so on) and mount it in a suitably elevated place on a wall. This CO detector will protect you and your family from dangerous carbon monoxide gas. The Kidde 5CO carbon monoxide alarm features a 10 year sensor life and is supplied with 2 x Duracell AA alkaline batteries to power the unit. The 5CO continuously monitors the CO levels detected within a room. These units can be wall mounted or free standing, and feature a 7 year manufacturer's warranty. Everyone knows how important it is to have a smoke alarm in the home. If a fire breaks out while you’re asleep, the smoke it emits will set off the alarm, hopefully giving you time to get out before being asphyxiated by the fire’s deadly concoction of chemical gases.The 7DCO comes with a ten-year lifespan and is BS EN 50291-2 certified for camping, caravanning and travel, or even use on a boat. As with all CO detectors, the Kidde provides end-of-life and battery warnings, along with the obligatory test/reset button for peace of mind. The only thing to watch out for is that it’s powered by a pair of AA batteries which need replacing roughly every two years We had no issues whatsoever during tests, but it means this alarm won’t be compliant with the new Scottish regulations. Carbon monoxide is known as the silent killer because you can’t smell it, taste it or see it. Once it enters your bloodstream, it invades the red blood cells (haemoglobin), preventing them from carrying oxygen around the body. Symptoms of carbon monoxide poisoning include a flu-like headache, dizziness and nausea followed by tiredness, confusion, breathlessness, weakness, loss of muscular coordination and – dare I mention it – death. CO is so odourless that even dogs can’t detect it. How do CO alarms work? The best carbon monoxide alarms you can buy in 2023 1. Nest Protect: Best smart CO and smoke detector

Battery powered carbon monoxide alarms can typically be installed wall-mounted or left free-standing on flat, level surface. The Kidde K5CO carbon monoxide alarm will protect you and your family from dangerous carbon monoxide gas, and features a 10 year sensor life. Supplied with 2 x Duracell AA alkaline batteries to power the unit, the K5CO carbon monoxide detector continuously monitors the CO levels detected within a room. These units can be wall mounted or free standing, and feature a 7 year manufacturer's warranty. The K5CO replaces its predecessor (5CO) and can be fitted to existing 5CO baseplates. Carbon monoxide sensors have a finite lifespan of between five and seven years, although a few manufacturers now claim that their sensors will last a full ten years. Generally speaking, it’s worth playing it safe and replacing your alarm a year or two before its life is supposed to run out. Tests in the US have shown that alarms over eight years old can fail to detect CO at levels of above 400ppm.

What's Included?

Also note that carbon monoxide has been proven to spread into neighbouring properties through open windows and, in semi-detached or terrace houses, through loft spaces. If your property has an attached garage with a connecting door through to the house, it is recommended to fit a CO alarm inside the house leading from that doorway.

CO detectors should be installed near potential sources of carbon monoxide, essentially any fuel-burning appliances such as boilers, cookers and ovens, fireplaces (both open and enclosed burners), and portable generators. As you are likely to be most affected by CO in areas of your home that you spend the most time in it is advisable to install alarms in those areas as well, such as the living room and bedrooms. It is also worth noting that while one detector is better than no detectors at all, larger homes may require several detectors to cover the property fully. The Nest Protect passed our sealed incense test with flying colours: the smoke alarm went off first, followed by the CO alarm five minutes later; according to the app, the CO level was 414ppm and increasing. We can’t think of a better CO currently alarm on the market, particularly as it also detects smoke. A reliable carbon monoxide detector should last seven to ten years. It is important to note that this figure relates to the working life of the sensor in the alarm, not the batteries that power it! (Some carbon monoxide detectors are mains-powered or sealed units that contain a lithium battery so the warning does not apply in these cases).Thankfully, there’s an early-warning solution in the form of a carbon monoxide alarm that costs only a few pounds more than a smoke alarm. Be aware, though, that not all CO detectors are sensitive enough and some no-name brands are downright useless – and, therefore, dangerous. Ensure you opt for a reputable brand such as FireAngel, First Alert, Kidde, Nest or Lifesaver. The one downside with this model is that it runs off a pair of AA batteries, which need to be switched out roughly every three years, making three changes during its lifespan. This isn’t a huge issue, but it means this model isn’t suitable for use in Scottish homes. It is, however, suitable for use in a boat or caravan, making it a good option if you need an alarm on your next boating or caravanning trip. The 10 year Kidde 5CO is a carbon monoxide alarm incorporating highly effective detector technology with slimline designer casing and a sleek finish. The alarm continuously monitors the CO levels in the air around it and LED indicators show the current status of operation, fault, or alarm. These units can be free standing and also have the option for wall mounting.

The health effects of CO depend on the concentration and length of exposure (carbon monoxide concentration is measured in parts per million). According to respected CO alarm manufacturer Kidde, “a carbon monoxide detector is a time-weighted alarm that measures the buildup of carbon monoxide in a house. For a person to begin feeling the effects of carbon monoxide poisoning, they would need to be exposed to a carbon monoxide level of 50 parts per million (ppm) for eight hours. An alarm’s response time will vary depending on the level of carbon monoxide in the air. For example, an alarm will sound after three and a half hours of continuous exposure at a level of 50ppm, yet will sound after eight minutes of continuous exposure at a level of 400ppm.”Near an appliance: they should be placed within 1 to 3 metres horizontally from the appliance and between the height of the appliance to 150mm below the ceiling – i.e., not above a stove where it would be in the path of steam or fumes. Most people will not experience any symptoms from prolonged exposure to CO levels of under, say, 40ppm. It depends on the length of exposure, but the real danger level starts at around 400ppm (two to three hours of exposure at this level can be life-threatening). To give you some idea of how dangerous higher levels of concentration can be, 1,500ppm could result in death within an hour and 6,000ppm within 15 minutes. Don’t think that CO alarms are just for your home, either. They’re essential for caravans and motorhomes, and you might even want to take one on holiday if you’re staying in a cottage or self-catering accommodation. Are there any features worth looking out for? The better carbon monoxide alarms feature an easy-to-read digital display that shows the carbon monoxide particle count, room temperature and battery level (assuming the unit is non-sealed). Some units store readings for the last few weeks. Unlike other CO detectors, the Nest notifies you (and anyone else who has registered) with a notification on your mobile device, even if you’re in another country. It also does the same for smoke. The main unit also speaks a warning in a calm English female voice when it detects smoke or CO in a room. If the CO levels are slowly increasing, the voice will warn you before setting off the alarm. But if CO levels become dangerously high, the centre lamp glows red and a very loud, high-pitched beep is emitted along with a spoken warning letting you know which room is affected. You can temporarily cancel any alarms by holding the “Stop” button on the app or by pressing the unit’s central button.