Contents

• Things to Consider When Buying Carbon Monoxide Detectors
• The Best Carbon Monoxide Detectors
• Stand-alone Carbon Monoxide Detectors
• Combination Smoke and Carbon Monoxide Alarms
• Compatibility with Home Security Systems

Things to Consider When Buying Carbon Monoxide Detectors

• Budget for Multiple Detectors:
  When you consider that you may need 4 detectors or more to cover all areas of your home, the price starts to add up - so make sure you leave enough room in your budget for all the detectors you need.

• Sensor Life:
  The sensors in a detector have a limited life span and the entire unit has to be replaced once the time limit is reached - this typically ranges between 5 and 10 years.

• Sensitivity:
  CO concentration levels are measured in Parts Per Million (ppm) with standard detectors measuring levels from 30-40 ppm and sounding the alarm with consistent levels over 70 ppm which is fine for most people. If you have special health concerns such as respiratory illness, advanced age, or pregnancy, then you might want to consider one which measures levels as low as 10 ppm.

• Digital Display:
  This is an important feature which some of the cheaper models don't have. These allow you to look through the history of CO levels since the last time you reset the detector - this is extremely useful for seeing if you have low levels of CO that don't trigger an immediate alarm but which might be harmful if exposure continues long term.

• Power Source:
  You have four main options:

  • Battery operated
  • Plug into a wall socket
  • Hard-wired into your home's electricity supply (this option usually requires a contractor to install)
  • Combination of wire-in or plug-in and battery backup

  A power blackout is a time of heightened risk of CO exposure because that's when many people are most likely to be using fossil fueled appliances such as heaters and power generators, so we advise only to get a detector which uses batteries and will continue working when the power goes out. So be very wary of hard-wired models that don't have some kind of battery back-up, fortunately there are fewer of these on the market these days than a few years ago.

• Manufacturer:
  Over the last year or so there have been a number of new low cost 'brands' appear on the market. Typically it's very hard to find out who the actual manufacturer is, which in turn makes it quite difficult to verify their claims or warranties - many of them have also not been certified by BSI (British Standards Institution - this includes Kitemark) or the EU with CE. For these reasons you won't find us recommending 'brands' like X-Sense (not to be confused with Honeywell's X-Series), Home Security Safe, or Yondwin.

The Best Carbon Monoxide Detectors

These are listed in two categories:

• Stand-alone CO Detectors
• Combination Smoke and CO Alarms

Please note that the prices listed below are subject to fluctuations so I've presented the approximate price that each unit typically sells for.

Stand-alone Carbon Monoxide Detectors

Stand-alone detectors are the option that most people go for because many of these offer the additional feature of a digital readout, or because they already have smoke detectors installed and don't need a combination alarm.

Kidde 10LLDCO

Manufacturer: Kidde | Price: Usually under £25

Power:	Sealed in 10 year lithium battery which can be activated and deactivated when necessary.
Sensor Life:	10 years
Digital Display:	Yes
Sensitivity:	The digital display will show levels down to 11 ppm. The alarm will sound at: 50 ppm detected over 60 to 90 minutes 100 ppm detected over 10 to 40 minutes 300 ppm detected in less than 3 minutes

Kidde did a brilliant job with the 10LLDCO and in my opinion it is the top CO detector currently available for the UK, beating out the competition with its excellent combination of features and value. One of its biggest selling points is that it comes with a sealed battery which lasts for 10 years, as does its electrochemical sensor. It has a digital readout which shows the current CO levels (updated every 15 seconds) or you can use it to see what the peak levels were since it was last reset. Although its up-front cost is a bit higher than some other detectors, the total cost of ownership is lower because of its long life backed by the manufacturer's 10 year warranty and the fact that you don't have to buy 10 years worth of replacement batteries. If you'd like to know more then please read this detailed Kidde 10LLDCO Meta-Review.
Get the latest Kidde 10LLDCO price & customer reviews at Amazon.co.uk.

Honeywell XC100D

Manufacturer: Honeywell | Price: Usually under £40

Power:	Sealed in 10 year lithium battery which can be activated and deactivated when necessary.
Sensor Life:	10 years
Digital Display:	Yes
Sensitivity:	The digital display will show levels down to 10 ppm. The alarm will sound at: 43 ppm or more detected for approximately 75 minutes 100 ppm or more detected for approximately 25 minutes 300 ppm or more detected for approximately 90 seconds It also has an optional pre-alarm which when turned on sounds at: 43 ppm or more detected for approximately 19 minutes 100 ppm or more detected for approximately 6 minutes 300 ppm or more detected for approximately 23 seconds

Honeywell are one of the leading brands in home safety and control equipment (you're probably already familiar with their thermostats). At this time they're less well known for their CO detectors which is surprising because they make some of the best detectors currently available. Although more expensive than most alternatives, the XC100D does have quite a few additional features including working in an environment with up to 95% relative humidity which Honeywell says means it can be used in bathrooms. Due to its heightened sensitivity the Honeywell XC100D is the best CO detector to get if you have anyone in your home with respiratory illness, advanced age, or pregnancy. Although Honeywell says it's upgradable to wireless by using the optional XW100 plug-in module, I have not been able to find any of these modules available to buy so I wouldn't count on this feature. It can be wall mounted or used free-standing. It also has the additional EN 50291-1: 2010 Recreational certification so it can be used in caravans and boats.
Get the latest Honeywell XC100D price & customer reviews at Amazon.co.uk.

Fireangel CO-9D

Manufacturer: Fireangel | Price: Usually under £25

Power:	Sealed in 7 year lithium battery.
Sensor Life:	7 years
Digital Display:	Yes
Sensitivity:	The digital display will show levels down to 10 ppm. The alarm will sound at: 50 ppm detected over 60 to 90 minutes 100 ppm detected over 10 to 40 minutes 300 ppm detected in less than 3 minutes

Fireangel is the second most popular brand of CO detectors in the UK and the CO-9D is their most popular CO alarm which is also one of the top sellers on Amazon.co.uk. Although it only has a 7 year life span, it does have one feature which the Kidde 10LLDCO above does not; it has a thermometer and can display the room temperature on the digital readout. It has also been tested and certified for use in caravans and motor caravans and is designed to be portable. Other than that it has all the features you'd expect including being able to show the current CO levels as well as the peak levels over the previous 4 weeks.
Get the latest Fireangel CO-9D price & customer reviews at Amazon.co.uk.

Kidde 7DCO

Manufacturer: Kidde | Price: Usually under £20

Power:	3 AA alkaline batteries - included
Sensor Life:	10 years
Digital Display:	Yes
Sensitivity:	The digital display will show levels from 11 to 999 ppm. The alarm will sound at: 50 ppm detected over 60 to 90 minutes 100 ppm detected over 10 to 40 minutes 300 ppm detected in less than 3 minutes

The Kidde 7DCO (AKA 7DCOC) is a best seller on Amazon.co.uk. It is essentially the same detector as the 10LLDCO above except that it doesn't have a 10 year battery - it uses 3 AA bateries instead which need to be replaced periodically (usually about once a year). By getting this one instead of the 10LLDCO you'll be saving a few pounds per unit up-front but you may end up spending more over 10 years due to the cost of replacement batteries. It's also missing the "Fault" LED - instead the Red LED flashes and the alarm chirps every 30 seconds to indicate that the unit must be replaced. The 7DCO has also been tested and certified for use in Boats and Caravans as well as homes. There is also a cheaper version which doesn't have the digital display: Kidde 7COC.
Get the latest Kidde 7DCO price & customer reviews at Amazon.co.uk.

Aico Ei208DW

Manufacturer: Aico | Price: Usually under £70

Power:	Sealed in 7 year lithium battery which can be activated and deactivated when necessary.
Sensor Life:	7 years
Digital Display:	Yes
Sensitivity:	The alarm will sound at: 43 ppm detected over 60 to 90 minutes 80 ppm detected over 10 to 40 minutes More than 150 ppm detected in less than 2 minutes

The special feature of the Ei208DW is that you can also buy the Aico Radiolink Fire & CO Alarm Controller which lets you control multiple alarms from a central point. This means you can remotely locate where the threat is, and you can also test and silence any alarms in your system. Aico is the UK subsidiary of Ei Electronics in the US which has been making fire safety products since 1988, and this particular detector is manufactured in Ireland. The Ei208DW can be mounted on a wall or it can be used as a portable detector. It has BS EN 50291-2:2010 certification as well as being Kitemarked to BS EN50291-1:2010 so it is suitable for UK landlords, home owners, and for use in caravans and boats. The digital display will show CO levels once 43 ppm is detected or when you want to see the recent peak levels. One minor downside is that although the sensor has a 7 year life the manufacturers warranty is only for 5 years.
Get the latest Aico Ei208DW price at Amazon.co.uk.

FireAngel W2-CO-10X Wireless

Manufacturer: FireAngel | Price: Usually about £50

Power:	Sealed in 10 year lithium battery which can be activated and deactivated when necessary.
Sensor Life:	10 years
Digital Display:	No
Sensitivity:	The alarm will sound at: 50 ppm detected over 60 to 90 minutes 100 ppm detected over 10 to 40 minutes 300 ppm detected in less than 3 minutes

What sets the FireAngel W2-CO-10X apart from the rest is that it makes wireless connections with any other FireAngel Wi-Safe 2 CO or fire alarms with up to 50 devices connected in a single network. This means that regardless of which particular sensor or alarm has detected a threat, that all alarms right throughout your home can all sound at once - this is particularly useful if you have a large home or one with multiple levels. It's designed to be portable, but it can also be wall mounted. It's certified to BS EN 50291-1:2010 and BS EN 50291-2:2010 which means it's suitable for homes as well as caravans and boats.
Get the latest FireAngel W2-CO-10X price at Amazon.co.uk.

First Alert CO410

Manufacturer: BRK | Price: Usually under £25

Power:	2 AA batteries.
Sensor Life:	5 years
Digital Display:	Yes
Sensitivity:	The digital display will show levels down to 30 ppm. The alarm will sound at: 70 ppm detected over 60 to 240 minutes 150 ppm detected over 10 to 50 minutes 400 ppm detected over 4 to 15 minutes

First Alert, by BRK Electronics, is a brand well known to many home owners so it's not surprising that many people want to get a First Alert carbon monoxide detector, and this is one of the few from this brand that is available in the UK. It's important to note that it's built to American standards which, as you can see from the table above, means that it is not as sensitive as ones built to UK or EU standards. I would not recommend this for Landlords, but it's perfectly fine for home owners who don't require extra sensitivity. If you'd like to read more then take a look at this First Alert CO410 Meta-Review.
Get the latest First Alert CO410 price & customer reviews at Amazon.co.uk.

The Best Combined Smoke and Carbon Monoxide Detectors

If you don't need a digital readout then buying combination detectors can save you a few dollars compared to buying both types of detectors separately. The reason these don't have digital readouts is because they need to be mounted on or close to the ceiling to do their smoke detection work effectively.

Kidde 10SCO with Voice

Manufacturer: Kidde | Price: Usually under £20

Power:	9v battery.
Sensor Life:	10 years
Digital Display:	No
Sensitivity:	The alarm will sound when: 50 ppm CO detected over 60 to 90 minutes 100 ppm CO detected over 10 to 40 minutes 300 ppm CO detected in less than 3 minutes Anytime smoke is detected

The Kidde 10SCO (AKA KID10SCO) is a top seller on Amazon.co.uk which is due largely to the fact that it offers the best value for money in its class. It tells you what the problem is when the alarm sounds so that you know if the danger is carbon monoxide or smoke. It also speaks when you want to know historical peak CO levels, when the battery needs replacing, and also when you've activated or deactivated the hush mode. It's designed to be mounted on either the ceiling or wall - I recommend mounting on a wall at about eye level for easy access. For more information please see: this Kidde 10SCO Meta-Review.
Get the latest Kidde 10SCO price & customer reviews at Amazon.co.uk.

Nest Protect

Manufacturer: Nest | Price: Usually Under £110

Power:	6 Lithium Metal batteries (included).
Sensor Life:	10 years
Digital Display:	No, provides information via Smart Phone or Tablet
Sensitivity:	The alarm will sound when: 70 ppm CO detected over 60 to 240 minutes 150 ppm CO detected over 10 to 15 minutes 400 ppm CO detected over 4 to 15 minutes Either smoke or fire is detected

Although the Next Protect costs as much as three times more than many of the alarms it competes with, it is still an Amazon top seller because it has a few features that the others don't have including:

• If you have a Nest Thermostat then Nest Protect can shutdown appliances such as your furnace or air conditioning systems in an emergency.
• It sends progress alerts to your phone or tablet letting you know if smoke and/or CO readings have fallen to safe levels.
• You can set it to detect movement at night and turn on a night light.
• You can view historical information via its App.

It also speaks and can tell you the nature of the alarm and where the problem is located - here's an example:

Nest go out of their way to make their products stand out from the rest, both in terms of features and aesthetics. You can read more in this Nest Protect review.
Get the latest Nest Protect price & customer reviews at Amazon.co.uk.

First Alert SC05UK

Manufacturer: BRK / First Alert | Price: Usually under £37

Power:	2 AA batteries.
Sensor Life:	5 years
Digital Display:	No
Sensitivity:	The alarm will sound when: 70 ppm CO detected over 60 to 240 minutes 150 ppm CO detected over 10 to 15 minutes 400 ppm CO detected over 4 to 15 minutes Smoke is detected

The First Alert SC05UK CO is certified to Certified to UL 217 & UL 2034 as well as EN 14604: 2005 & LPS 1282 Issue 1.0 so it is suitable for both home owners and UK landlords. Although it doesn't have all the features of the other models listed here, I have included it because it's currently the best offering from the First Alert brand in the UK. It utilises two different alarm sounds and flashing LEDs to indicate whether the threat is smoke or CO. It also gives you a 30 day low battery warning. Although Amazon.co.uk lists some of the features differently to the manufacturer you can get the official datasheet here.
Get the latest First Alert SC05UK price & customer reviews at Amazon.co.uk.

Compatibility with Home Security Systems

There are also carbon monoxide detectors which are designed to work with home security systems. Some of these detectors will only work with specific brands of security systems. Some have 'open protocols' so that theoretically they could work with any compatible standard, however many of these have only been certified when used with the same brand of security system. For these reasons I have not listed any of these types of detectors here - if you have a home security system and you'd like your CO detectors to work with it, then contact the manufacturer to find out which detectors are compatible.