Best Carbon Monoxide Detectors

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Carbon monoxide is a completely odourless and tasteless gas which is caused by incomplete carbon combustion. It is not as dense as air. Carbon monoxide is poisonous and can kill you if you are exposed to high levels which is why Carbon Monoxide detectors are so important.

Carbon Monoxide is made up of a carbon atom and an oxygen atom these are connected with a triple bond that is made up of two covalent bonds and a dative covalent bond.

Best Carbon Monoxide Detectors

What are the Best Carbon Monoxide and Gas Detectors?

There are many different kinds of carbon monoxide detectors available to purchase, ranging from very basic battery operated detectors to smart devices with digital displays.

They are available for all budgets and should be a priority for your property.

The different types of carbon monoxide detectors are:

  • Battery operated: The most basic of carbon monoxide detectors, these can come with or without digital displays. It is very important that you do regular checks of the batteries, this is achieved by pressing the test button on the detector. A good practice is to perform this test once every 3 months.

  • Smart detectors: The Smart carbon monoxide detectors are the most advanced detector you can buy and are also the most effective. They allow you to monitor your home even when you are not thereby syncing with the latest smart home automation apps and devices. Smart Carbon Monoxide detectors do all of their own tests and diagnostics to ensure the highest level of safety.

  • Dual Purpose: Dual purpose detectors not only test levels of carbon monoxide but also can act as smoke alarms and test the atmosphere for dangerous levels of other gases.

  • Hardwired: The hardwired carbon monoxide detectors do not use batteries and are wired up to your main power, some believe that these are safer than battery operated detectors as there is no danger of the batteries running out if you forget to check, however, if you have a power cut while sleeping, for example, it would impose a danger,these also have their own dangers as the detector will stop working.

  • Digital: Digital Carbon Monoxide detectors have a digital LCD display which allows you to observe the levels of carbon monoxide present in the house. The LCD display will give a digital readout.

There is no excuse for not buying a carbon monoxide detector as there are many ways to get one. You can buy via hardware shops or simply have them delivered to your door from reputable marketplaces online like Amazon.

I’ve done some extensive research on the best Carbon Monoxide detectors and will list one of each of the types that we have just discussed. The carbon monoxide detector that I will list under each of the categories will be the best in that range and the one with the most positive reviews and feedback.

1. Kidde 7DCO Battery Operated Carbon Monoxide detector

Main Features

  • Battery Operated with the 3 AA batteries included, these provide protection during a power cut.
  • Two red LED’s and one Green, The red LED is activated when in alarm mode and the green when the DC power is present and is operating normally.
  • A Test & Reset Button which test the CO alarm circuit operation and also allows you to silence the alarm.
  • Digital Display which allows you to continuously display the CO levels that are detected.
  • An End of Life Alarm will alert you, the user, to replace the alarm after the 10 years of protection is over.


The Kidde 7DCO Carbon Monoxide detector comes with a 10-year sensor and warranty.

Kidde 7DCO Quick Review

The Kidde 7DCO alarm is powered via a DC outlet but also has battery operation to protect you from a power cut as we discussed earlier making it a very effective and safe choice of alarm.

Kidde is a brand you can trust and are one of the world’s largest manufacturers of fire safety devices and products.

For under $20 this carbon monoxide detector has many great features and has been received very well by its users.

I like that you can either install this or use it as a tabletop unit, meaning that you could actually take it with you if you are sleeping in another property like a hotel a boat or even a caravan.

2. Nest Protect 2nd Generation Carbon Monoxide & Smoke Detector

Main Features

  • Dual detector for both smoke and carbon monoxide.
  • Nest Gen 2 will protect you even when you are not at home by alerting your phone when something is wrong for example, carbon monoxide, smoke, sensor failure and battery levels.
  • Detect both fast and slow burning phones with the split-spectrum sensor
  • Nest will tell you exactly what is wrong and where the problem is located.
  • Nest Protect can be silenced from your phone using their special app.
  • Nearly double the life of standard carbon monoxide detectors Nest has a 10-year product lifespan.
  • Battery powered: Six long-life AA batteries


Nest Protect 2nd Generation comes with a 2-year warranty when installed yourself, or 5 years if installed and purchased from a Nest pro.

Nest Protect 2nd Gen Quick Review

The Nest Protect 2nd Gen is the most sophisticated of the models I have listed on this page and the most expensive.

It protects you against both Carbon monoxide and smoke, it also has low battery indication and will alert you if there is any kind of failure with the system.

It’s very simple to install and works seamlessly when setup with your phone and their app.

It can be used in conjunction with more than one unit thus allowing the nest protect system to tell you exactly where and what is going on in your property when you are away with the alerts it will send to your mobile device.

The list of features is exhaustive, but that doesn’t make the Nest overcomplicated the guides and setup are very straightforward.

Nest is the future of home protection and if you can afford it then I would highly recommend this system, a very good friend of mine swears by it and when I can afford the setup I will be installing one in all of the rooms in my property.

Tests to see how the Nest Protect 2nd gen is functioning can be run via the app on your phone and will display and store the results and all of the previous results.

Other nice features include the night light which gives a little green glow when you turn out the lights in a room to give you the peace of mind that Nest is there and protecting you.

Highly recommended and the future of home carbon monoxide and smoke alarms!

3. Kidde 10SCO Combination Smoke & Carbon Monoxide Alarm

I have put this under the best combination smoke and carbon monoxide detector, however, the Nest I previously mentioned under smart devices is also a combination detector and if your budget stretches would also be my top choice!

Main Features

  • Voice Alarm feature which tells you the danger that has been detected even after the event.
  • Easy battery changing with front-loading battery compartment.
  • Silence button which temporarily silences false alarms.
  • Test button which allows you to regularly test the alarm function
  • 9 Volt Battery operation (supplied)


The Kidde 7DCO Carbon Monoxide detector comes with a 10-year warranty.

Kidde 10SCO Quick Review

The Kidde 10SCO is a dual detector which detects both Carbon Monoxide and smoke. The built-in voice feature will alert you to which danger is present.

It is designed to either be wall or roof mounted and is easily installed. You simply attach the backplate via screw to the ceiling and then you place the unit onto the backplate. A ten minute job and you’re all done!

The unit is very simple and compact, a true no-frills reliable budget dual detector.

Kidde is one of the leading detector manufacturers and their carbon monoxide alarms are very popular and well received.

The Kidde 10sco  dual alarm is a budget detector and has made the Amazon choice status with many positive reviews.

4. Mains Powered Kidde 4MCO Carbon Monoxide Alarm

Main Features

  • Powered by mains 230v with a 7 Year Sealed backup lithium battery
  • CE & Kitemarked to BS
  • Possible interconnection with the Kidde Firex smoke & heat alarms
  • 30ppm parts per million CO gas sensitivity level
  • Test & reset button for regular testing
  • Choose between standard LED or digital display.
  • 7-year  lifespan
  • 6-year manufacturers warranty
  • The unit will give you an end-of-life warning when it is about to run out.
  • The 85dB audible alarm is very loud and clear.
  • LED displaysan alarm state, low battery warning and end of life.
  • The Digital display shows early warnings of regular low CO levels and will show fire or CO when connected to the other Kidde alarms.


The Kidde 4MCO Carbon Monoxide detector comes with a 6-year manufacturers warranty.

Kidde 4MCO Quick Review

If you’re renovating, rewiring or even building your home the Kidde 4MCO detector is ideal and convenient. It is mains powered with a backup battery in case of power failure.

A very durable and well-built unit with everything you need from a Carbon Monoxide detector.

As per most Kidde alarm models they are very straightforward and easy to fit and install.

Discreet and unobtrusive with a very loud alarm system.

The Kidde 4MCO is also inter-connectable with the heat and fire alarms.

A little bit more expensive mainly due to the fact it is hardwired via the mains power, but for 7 years protection a small price to pay.

5. Fireangel CO-9D Digital Sealed for Life Carbon Monoxide Alarm

Main Features

  • A self-diagnostic feature allows the unit to perform its own regular tests.
  • 7-year lifespan sealed unit with a built-in Lithium battery.
  • Very loud and clear 85dB alarm.
  • Large Test & Silence button for easy muting of false alarms and testing the functionality.
  • Large easy to read multi-function LED Digital screen with temperature display.
  • Temperature readouts designed to provide a room temperature indication.


The Fireangel CO-9D comes with a 7-year manufacturers sensor warranty and lifespan.

Fireangel CO-9D Quick Review

Perhaps the most popular digital carbon monoxide detector in the world and also the award-winning “Which best buy”

The Fireangel CO-9D unit can be mounted to a wall, roof or be kept as a portable alarm system meaning you can take it wherever you go on your travels.

Packed with features and very reliable and well built the Fireangel CO-9D alarm is everything you expect and need in a detector.

The digital display tells you the amount of carbon monoxide present in the room and also gives you a temperature readout. It also has a historic display which allows you to view previous CO levels.

An absolute bargain price for a digital detector and also comes with Amazon’s choice title!

What are the best carbon monoxide detector manufacturers and brands

What are the best carbon monoxide detector manufacturers and brands?

When buying a carbon monoxide detector or alarm it is the safest option to do a little research beforehand which I hope is why you are here. To ensure that you are buying a quality product that will save your life then naturally it is better and safer to stick with established brands that have departments and the resources for carrying out tests on their products.

There are a couple of main manufacturers that dominate the market in carbon monoxide detector production here’s a little information about them.


The company Kidde was first founded by Walter Kidde in 1917 and are now perhaps the largest manufacturer of fire and carbon monoxide alarms and detectors.

They are well known for their charitable approach as a corporation and donate over 100,000 units per year to non-profit organisations and fire departments. All of their products are thoroughly tested and guaranteed and are trusted by millions of people worldwide.

Not only do they produce Carbon Monoxide alarms but they also produce a range of other safety equipment like fire extinguishers, safety escape ladders, Smoke Alarms and numerous security devices.

If you see the Kidde brand you can rest assured it is a quality and safe product.


Fireangel is based in Europe and is one of the leading manufacturers of home safety devices and products. Due to the quality and reliability of their safety products, statistically, they are now used by over 90% of the UK’s Fire and rescue services.

The Fireangel company have a full team and department that are dedicated to rigorously testing all of the products they develop, approximately 55 tests are made before they can pass a smoke detector. So you can rest assured that Fireangel is a very safe brand for your carbon monoxide detectors.

Frequently Asked Question

What is the difference between a carbon monoxide detector and a smoke detector?

Smoke detectors are used to detect smoke which is generated generally by fire, flames or smouldering fires. Carbon Monoxide detectors are not used to detect smoke they are used to detect dangerous levels of Carbon Monoxide (CO) this odourless killer gas is created usually by fuel burning devices that are not functioning correctly.

In 2018 there are also now many dual detectors available and these will detect both carbon monoxide and smoke and alarm when dangerous levels are present.

What sound does a carbon monoxide detector make?

Carbon Monoxide detectors make a beep sound or a “chirp” to alert you to the dangerous presence of CO in the air. This is often represented by 4 chirps or beeps. The detectors will continue making these sounds until the Carbon Monoxide is not present or you mute the Carbon Monoxide detector. Muting the detector is a very unsafe thing to do.

What is the life expectancy of a carbon monoxide detector?

Generally speaking, your Carbon Monoxide detector should have, on the back, an expiration date or some form of indication on how long your detector is good for. 5 – 7 years is the usual time frame for the life expectancy of a Carbon Monoxide detector.

How do you know if a carbon monoxide detector is working?

To check the status of a carbon monoxide detector and to determine if it is working then you can press the test button located on the device. The detector will then tell you if it has enough power or needs the batteries replacing. If the detector does not make a high pitch chirp noise then it will either need new batteries or will need to be completely replaced.

Please note this is not a thorough test, this will tell you only if the device has enough power.

Is it a legal requirement to have a carbon monoxide detector?

For landlords, it is a legal requirement when renting out properties.

How many Carbon monoxide detectors are required in a home?

There are first and foremost a couple of aspects you will need to take into consideration, the size of your house and the number of bedrooms. There is no required amount but it is a good practice to have one in the kitchen and one near each bedroom.

Why does my Carbon Monoxide detector keep going off for no reason?

Well, firstly you need to make sure that the CO detector is actually going off for no reason and not trying to tell you that there is carbon monoxide present. Remember that Carbon monoxide is invisible and odourless! If you are sure there is no danger and the detector keeps going off this could be for a couple of reasons.

Check your batteries, CO detectors have a safeguard built in that alerts you when your batteries are running low.

Ensure that none of your gas hobs or oven has been left on.

How long do Carbon Monoxide detectors and alarms last for?

Each detector is different and lasts for a different amount of time. Your detector should ideally have a date on the back for when it will run out if not you should check with the manufacturer of your device. Generally, though carbon monoxide detectors last for between 7 and 10 years.

What are the symptoms of carbon monoxide poisoning?

If too much carbon monoxide is present in the air around you it can cause carbon monoxide poisoning, carbon monoxide poisoning takes place as your body replaces the oxygen that your red blood cells contain with carbon monoxide. This, in turn, can cause death and very serious tissue damage.

The symptoms that are most common when someone has carbon monoxide poisoning are as follows:

Headaches, Weakness, Blurred and impaired vision, Lack or shortness of breath, loss of consciousness, vomiting, nausea, dizziness and confusion.

What is a carbon monoxide detector?

A Carbon Monoxide detector is a safety device found in most properties, also known as a CO detector, the device will detect any potential Carbon monoxide in the air. These detectors are of the utmost importance and can potentially save lives by preventing carbon monoxide poisoning.

The Carbon Monoxide detectors measure the carbon monoxide levels in the air and will sound a warning alarm to alert people of the danger if high levels are found in the atmosphere. When a Carbon monoxide detector alarms it is time to evacuate the area or create ventilation. Some of the CO alarms will alert the correct emergency services.

Do carbon monoxide detectors work?

Yes! Carbon monoxide detectors have literally saved millions and millions of lives since they were first ever invented. Of course, there can be a failure of the devices but this is usually down to human error and complacency for example not checking the battery power of the device regularly.

Carbon monoxide detector where to place?

Carbon monoxide detector where to place

The best general practice for the placement of your carbon monoxide detectors is to have one in each of the main areas of your property ie the kitchen, the lounge and in the bedrooms. Most people choose to have just one Carbon Monoxide detector, however, for maximum effectiveness and safety, you really should place them throughout your house.

It is a good idea to have them placed close to where you sleep as this is when Carbon Monoxide is probably at it’s most dangerous as you wouldn’t be aware of the effects it is having on you.

Should a carbon monoxide detector be placed high or low?

Carbon Monoxide detectors are at their most effective when they are placed at 5 feet from the ground. This is where they get their optimum reading on the quality of the air.


The best carbon monoxide detector, in my opinion, is the Nest 2nd generation, it really is the future of home carbon monoxide and smoke protection, that being said 99% of the available detectors out there will be sufficient protection.

Always look for safety standard seals and a good warranty when buying a CO detector.

Every home should have at least one CO detector they truly are life-saving units.

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