Best Carbon Monoxide Detectors

Over the years we’ve grown used to the presence of smoke alarms in most homes and businesses. They’re ubiquitous and reassuring and have a proven safety track record. Carbon monoxide alarms (CO), on the other hand, are relatively new to the home market. More and more people are becoming aware of what a crucial role they can play in terms of home safety. They are vital in protecting us from deadly poisonous gases that are both odourless and invisible, and because of this it is universally agreed that every home should have at least one installed. 

However, not as much is known about carbon monoxide detectors. They are a more recent addition to the market than smoke detectors. What’s more, as more become available on the market, it can be difficult for anyone without expert knowledge to get their heads around the technical specifications of the multitude of models available. So, we’ve tried to put together a list of the seven top carbon monoxide models available on the market right now.

Kidde 5CO 10 Year Life LED Carbon Monoxide Detector

The Kidde 5CO detects carbon monoxide gas and gives a loud acoustic warning if this poisonous by-product of incomplete fossil fuel burning is present. It’s important to note that this is just a CO detector/alarm, and not a combination of CO and smoke detector/alarm. Nevertheless, it is an essential lifesaver that every home with gas or solid fuel heating needs. Excellent customer reviews across all platforms and scores highly in terms of efficiency and value for money.

Talking about the design details, it is great to know that it will monitor CO2 24/7 365 days a year. In addition to that, it is a convenient product that can be installed near almost any CO2 source including boilers and stoves. It operates on AA batteries and will trigger an alarm once the battery life is about to drain. The interface of this CO2 detector is newbie-friendly and comes down to monitoring the activity via the green and red LED display. To top that off, it comes with a 10-year limited warranty that is perfect if you are worrying about built-in defects. The only issue is that the batteries are not easy to replace especially if you’ve removed the tab.


  • Continuous monitoring
  • Can be positioned in all rooms with boilers, stoves, or open fires
  • End-of-life alarm
  • Test/reset button
  • Battery operation
  • Multifunction green and red LED display
  • Early warning alarm to protect against the first signs of carbon monoxide build-up
  • Alarm sounds and lights flash before dangerous levels of CO are reached in the room
  • 10-year sensor life span
  • 10-year replacement guarantee if faulty


  • The warning signal for high levels of CO2
  • Newbie friendly with a simple installation process
  • Comes with a 10-year warranty for built-in defects
  • Powered by two AA batteries
  • Can be placed near any CO2 source


  • Batteries aren’t that simple to replace after tab removal

Check price at Amazon

Fireangel C0-9D Digital Sealed-for-life Carbon Monoxide Alarm

The Fireangel CO-9D digital 7-year life carbon monoxide alarm provides an early warning of the presence of CO in your home. The digital LCD display shows low levels of CO down to 10ppm and peak readings over the previous 4 weeks. Excellent customer reviews across all platforms and scores highly in terms of efficiency and value for money.

Offers continious CO2 monitoring no matter even when there is a power outage. Highlighted by a photoelectric sensor that is set to detect fire and high levels of CO2 near the source. Pretty simple to install and operates on long battery life. Most importantly? You don’t need an electrician to set this product up. It is great to know that the battery can be replaced without removing the alarm making this product newbie-friendly and minimizing the risk of faulty appliances. The only issue? The alarm could be louder. 


  • 7 year sealed-for-life lithium battery
  • Portable appliance so can removed from the home to use on holidays.
  • Can be positioned in all rooms; bedrooms, living rooms, kitchens, boiler rooms
  • Ease of installation
  • Room thermometer function designed to provide temperature indication
  • Certified to BS EN50291-1:2010+A12012 & BS EN50291-2:2010


  • Highlighted by a 7-year limited warranty
  • Can be installed near almost any CO2 source
  • Newbie-friendly with an easy battery replacement
  • Comes with an accurate photoelectric sensor
  • Offers continious monitoring even when there is an outage


  • The alarm should be louder

Check price at Amazon

Google Nest Protect

Nest Protect is a combined smoke and carbon monoxide alarm with a split-spectrum smoke sensor to detect both fast -and slow-burning fires. It can send an alert to your phone, speak to you, and even light the way in the dark. It tells you what the danger is and where it is. The Split-Spectrum Sensor looks for both fast-and slow-burning fires.  Google Nest Protect has garnered excellent all-round reviews for both its specifications and efficiency. However, it is considerably more expensive than the other carbon monoxide alarms on offer – though you also get an added smoke alarm for the price.

One of the coolest points about this product is that instead of a buzzing alarm it alerts you in a pre-recorded human voice if there are high levels of CO2 or fire on going in your house. In addition to that, it is the Spectrum Sensor that plays an essential role in detecting the source of the ongoing threat. 

We were pretty happy that the app Google Nest Protect can be connected to sends notifications and alerts in a matter of seconds. Thus, if you are outside of your property you are still to know if something went wrong. Also, you can use this app to silence the alarm in case the levels of smoke don’t present any danger but are rather a normal phenomenon while you are in the kitchen. The main downside? The fact that the installation is pretty complex and takes over 60 minutes.


  • Nest Protect has a 10-year CO sensor so that it can tell you where poisonous, invisible CO is hiding.
  • Nest Protect can alert your phone when you’re out and about that if something is wrong at home. You’ll receive a message if the alarm goes off if the batteries start to run low or if a sensor isn’t working. And you can silence your Nest Protect using the Nest app
  • Nest Protect checks itself over 400 times a day and lets you know if something is wrong.
  • Nest Protect also has Steam Check, so hot steam from baths and showers shouldn’t trigger false alarms. Pathlight will light your way at night
  • Easy to install. Nest Protect only takes minutes to set up with your iOS or Android device. Once you’ve added each of your Nest Protects to your Nest account, they will automatically connect to each other. Nest Protect is also simple to attach to the ceiling, thanks to a neatly designed back plate.


  • Comes with a 10-year warranty on all manufacturer defects
  • Human voice alarming you on levels of smoke or CO2 
  • Simple to connect with an iOS or Android app 
  • You can adjust the alarm volume and silence it in case of low smoke levels
  • Highlighted by a sophisticated construction


  • Pretty tricky to install (takes over 60 minutes)

Check price at Amazon

YZIF Carbon Monoxide CO Alarm Detector

YZIF Carbon Monoxide Detector CO Alarm Detector battery-powered with digital display and sound alarm for home use. Easy to install, very good competitive price and well regarded by buyers online. Good value for money considering the specification.

While it comes in White-only, this CO2 and fire detector is pretty sophisticated. The highlighting feature is the sounding alarm that is set at 85 decibels once it detects higher levels of CO2 or smoke. Most importantly, you can adjust and lower the volume in case it was triggered by smoke that is not endangering your family or your property. It is made out of ABS and should withstand years of heavy use especially given the two AA batteries that it operates on and that is pretty simple to replace.

Talking about the sensor, it uses a Certified Carbon Monoxide detector that can be installed near any CO2 source. It is easy to install and comes with a readable LCD. The only issue? The test function has some glitches.


  • Light and Sound Alarm Warning: When a dangerous level of carbon monoxide is detected the red LED will flash and the alarm pattern will sound 85-decibel alarm to protect your family’s life and property safety from CO detector.
  • Alarm Standard: the alert time depend s on the level of carbon monoxide concentration. 50ppm, alert within 60 to 90 minutes; 100ppm, alert within 10 to 40 minutes; 300ppm, alert within 3 minutes.
  • High Quality CO Alarm, EN 50291 Certified Carbon Monoxide detector equipped with high accuracy and reliable long-life electrochemical CO sensor to detect CO gas leak quickly
  • Power Supply: (DC3V) 2AA size batteries. (Not included) Sensor Type: Electrochemical Gas Detection Type: Carbon Monoxide Material: ABS


  • Comes at an affordable price
  • Made out of ABS plastic and with sealed two AA batteries
  • Simple to install near the CO2 source
  • Readable LCD with a red and green indicator
  • Triggers a sounding alarm at 85 decibels


  • The test feature is glitchy

Firehawk CO7B-10Y Carbon Monoxide Alarm Detector with 10-year battery

Firehawk CO7B-10Y Carbon monoxide alarm. Battery operated. Sealed-in long life lithium battery. 10 Year sensor. Automatic sensor test. End of life indicator. Alarm silence. Excellent reviews overall for this cost-effective CO alarm. Easy to install, easy to use and with good battery life. Great value for money considering its technical specification and performance. The only criticism is once the batteries are spent, the device needs to be replaced, rather than just the batteries.


  • Sealed 10-year Lithium battery
  • End of life indicator
  • LED indicators
  • Versatile mounting system
  • Compact & stylish design


  • Comes at an affordable price
  • Made out of ABS plastic and with sealed two AA batteries
  • Simple to install near the CO2 source
  • Readable LCD with a red and green indicator
  • Triggers a sounding alarm at 85 decibels


  • The test feature is glitchy

Buy it on Amazon

Honeywell XC70 Carbon Monoxide Detector Alarm – BNIB 7

The Honeywell XC70 has an attractive, compact design and can be used as a free standing or wall mounted unit according to your requirements. The XC70 has a reduced sound level test feature, allowing you to test the detector without the full 90dB alarm sound level. Certified for use in caravans and boats as well as domestic applications, the Honeywell XC70 carbon monoxide detector features a sealed long-life lithium battery, giving the detector a lifespan of up to 7 years. Generally, receives good customer reviews for efficiency, specification, and competitive pricing.

Most importantly, it offers a sensitive CO2 detector and sounds like a loud alarm that you can’t ignore. Our issue? The fact that the installation instructions aren’t that clear. Still, if you’ve had previous experience with CO2 detectors the setup shouldn’t be a problem.


  • Up to 7-year lifespan and manufacturer warranty
  • Battery powered – sealed lithium long-life battery. 90db alarm
  • Certified for use in caravans, on boats and domestic applications
  • Separate coloured status LEDs for alarm, power, fault and ventilate
  • Suitable for free standing or wall mounting


  • Comes with a 90-decibel alarm
  • Can be mounted on a wall or set in a vertical position on a shelf
  • Highlighted by a long-battery life
  • Comes with a 7-year warranty on all manufacturer defects
  • With a readable display featuring red and green indicators


  • Installation features aren’t that clear

Buy it on Amazon

Fireangel C0-9X Carbon Monoxide Alarm

Compact and portable carbon monoxide alarm; provides early warning of the presence of CO through the alarm and LED display.  Advanced electrochemical sensor with a loud, clear alarm. A large test button and end-of-life alert. Wall-mountable or portable for home or travel. 7-year sealed-for-life battery. Excellent reviews for price, specification, and reliability. The only complaint, as is the case for many sealed-for-life battery models, is that once the batteries are exhausted the alarm becomes redundant, though for the relatively small initial outlay perhaps this isn’t too much of an issue after a 7-year life cycle.

It is perfect for people who are on a limited budget but don’t want to miss out on the CO2 detector. It offers a large test and silence button allowing you to have full control over the operation of this product. The main downside? It isn’t as easy to wire in.


  • Automatic self-diagnostic check, 7 years sealed for life lithium battery, loud 85 dB alarm at 1 meter, large test and silence button, visual LEDs for power, alarm, and fault
  • 7 years sealed-for-life lithium battery
  • Loud 85 dB alarm at 1 m
  • Large test and silence button
  • Visual LEDs for power, alarm, along battery fault


  • Comes with an automatic self-diagnostics
  • Highlighted by a long battery life of up to 7 years
  • With a sophisticated test and silence feature
  • The sounding alarm of up to 85 decibels
  • Comes at a great price


  • Not that simple to install

Buy it on Amazon

Scondaor Carbon Monoxide Alarm Detector EN50291 Certified

The Scondaor Carbon Monoxide Detector is a battery-powered LCD Display CO alarm featuring a durable and high-quality CO sensor can provide 10 years long time protection for you and your family. After 10 years operation, the alarm beeps twice every 45 seconds and LCD display “End” indicating it is time to replace the detector. Generally received good reviews for pricing and efficiency, though the build-quality can sometimes be hit and miss. Most customers seem to be pleased with the CO alarm, baring initial teething problems. The only issue? The fact that it doesn’t seem to register lower levels of CO2. 


  • EN 50291 Certified Carbon Monoxide Detector: High accuracy and reliable long life electrochemical CO sensor and the CO alarm detector complies with EN 50291 standard.
  • Sound 85dB audible alarm and Red LED flashes when dangerous level CO gas is detected to alert home members effectively
  • Large Digital LCD Screen: Display CO concentration PPM Level and Battery status. And three LED indicators display three working statuses: Red (Alarm mode), Yellow (Fault mode), Green (Power On, Normal Standby mode)
  • TEST/MENU Button: Press “Test” to manual test the CO alarm circuit operation to ensure the proper working and Press “MENU” to view the alarm record. The alarm features self-test function automatic detect hardware failures such as internal circuit and CO sensor in normal standby mode to ensure the alarm always proper operating
  • 3×1.5V AA Battery operated (Battery Not included). Alarm features Low Battery warning to alert users to replace the batteries. Alarm features End of Life warning to alert user to replace the alarm after 10-year operation
  • Widely Used: Carbon monoxide alarm detector can be wall-mounted or free-standing- the best choice for home or travel


  • It is newbie-friendly with a simple installation process
  • Highlighted by a readable LCD
  • Long battery life of up to 10 years
  • Can be installed near any CO2 source


  • Doesn’t detect low CO2 levels

Buy it on Amazon

Buyer’s Guide

Before purchasing a carbon monoxide detector, there are a few factors you need to keep in mind to ensure you purchase the correct model for your needs. We will take a look at the primary considerations below.

Local Regulations

Before settling on a particular carbon monoxide detector, you should check your region’s regulations. Your state or town could have particular requirements on what to use, detector placement, and types considered. Additionally, some insurance firms provide discounts for homes that have smoke detectors.

Detector Display

Most carbon monoxide detectors don’t come equipped with a display. Nonetheless, many units feature small lights that blink steadily or glow on normal operation, an alarm, or an error. For extra information from the detector, go for models with a display to read carbon monoxide levels in parts per million, the highest levels recorded, a status update on battery life, and room air temperature. 

The Power Source

A hardwired carbon monoxide and smoke detector is typically linked to the house wiring and therefore requires professional installation. It usually has backup batteries. However, installing battery-only detectors is simpler as they will continue working despite power failures. Some models are powered by removable batteries that need annual replacement. Others utilize sealed lithium batteries with a lifespan equal to that of the detector. You can also choose a plug-in detector, though electrical sockets are usually located on inconvenient wall sections, with the best detector placement being near or on the ceiling. 

Sealed battery detectors have batteries sealed in the units. When the batteries start to run out, that alarm starts chirping, notifying you that the unit needs replacement. It is a tamper-proof battery unit, with some models having about 10 years of a lifetime before replacement is necessary. Getting a sealed battery carbon monoxide detector is an excellent idea if you want to avoid constant battery replacement every year.

Replaceable battery detectors, on the other hand, require battery replacement once every two to three years. However, the alarm lasts five to 10 years with such a detector. Replaceable battery detectors are often cheaper than sealed battery types. Nonetheless, since the batteries require replacement after a couple of years, the cost is almost similar. 

Smart Detector or Not

Smart carbon monoxide and smoke detectors offer you the benefit of identifying whether there is something wrong when you are away from home. However, the devices have a greater price tag. If you fit your home with such a detector, experts recommend installing extra dual-sensor smoke detectors. A battery-powered or hardwired smart detector also interconnects with similar model detectors.

Check for UL Stamp

Check on the packaging of the detector to ensure that it meets the standards of Underwriters Laboratories, indicated by a UL Label. Also, check the manufacturer date printed towards the backside of the detector. With time, units lose sensitivity, so a newer device is better. The rule of thumb is to replace carbon monoxide detectors after five years and after 10 years of smoke detectors. 

There have also been announced updates on UL standards, which need all manufacturers to make detectors capable of distinguishing between cooking smoke and smoldering fires. Initially, it was intended to be effected by June 2021 but has been delayed twice due to supply chain issues. The new effective date is June 2024. As part of the updated standard from Underwriters Laboratories, the expectation is that manufacturers stop producing conventional single-sensor smoke detectors. 

Detector Interconnection 

It is possible to interconnect some carbon monoxide and smoke detectors to ensure all the house units raise the alarm as soon as any of them are triggered. Modern homes may already feature wiring that links the detectors. Homes without this kind of wiring require detectors that you can wirelessly interconnect. Such interconnected carbon monoxide and smoke detectors are vital for homes with several levels, though standalone detectors might be sufficient for small single-level houses. 

While your home is much safer with interconnected alarms, they have shortcomings. Usually, an interconnected alarm may interconnect only with the same brand models. As such, ensure you check with manufacturers to see the models compatible with the brand. Also, note that some brands change the interconnect system with time.

The limitations notwithstanding, interconnected detectors are recommended. They enhance the home’s safety by informing you of danger before spreading carbon monoxide or fire throughout the house. 

Voice Alert Feature

A child typically sleeps much deeper than an adult, and a traditional alarm may fail to awaken them. Some detectors use voice commands, though it is still uncertain what the most efficient means of waking children is. Studies have shown many children between the ages of six and 12 awake to the sounds of the prerecorded voice of the mother than alarm tones.

Some carbon monoxide detectors feature audible alarms with 85-decibel sounds. However, some models feature voice alarms. Functionality differs from device to device, though they can alert of danger or specify where exactly a threat is detected. 

The Type Of Security System

One can combine some carbon monoxide and smoke detectors with security systems to sound alarms inside and outside the house. These systems usually have monitoring services to notify the fire department or police or call your mobile phone. 

The Type Of Detector

Your monitoring requirements influence the carbon monoxide detector type ideal for you. For example, if smoke detectors are installed, then a unit tailored to identify carbon monoxide will be enough. Nonetheless, suppose you want a unit to detect carbon monoxide and smoke or live in areas that necessitate both of them. In that case, it will be more efficient to install combination devices to meet legal and safety requirements. 

Sensitivity and Sensors

A carbon monoxide detector will use electrochemical sensors to identify the colorless and odorless gas presence. The sensitivity of the detector must be in line with UL safety standards. The standards specify that carbon monoxide detectors should trigger an alarm less than 15 minutes after carbon monoxide levels reach 400 PPM, in under 35 minutes for levels of up to 200 PPM, and in under 90 minutes for levels of up to 100 PPM. 

CO alarm sensors may become damaged by particles in the air. Therefore, avoid installing the detectors in furnace rooms since the detector’s sensor could become damaged or clogged by tiny particles ejected from the furnace. 


How frequently should I replace my carbon monoxide detector?

Usually, a carbon monoxide detector will have a five to 10-year life span. Once the detector nears the end of its life span, it typically triggers an alarm. To distinguish this end-of-life span detector alarm from carbon monoxide alarms, seek guidance by looking at the product or checking its packaging for details on the difference between the alarms. 

An end-of-lifetime alarm is usually a series of low beeps occurring every few minutes. A carbon monoxide detector will often have some space on it to label the date of purchase to ensure you remember to replace it once it reaches the end of its lifespan. 

Where is the ideal location to place a carbon monoxide detector?

It would be best if you placed carbon monoxide detectors close to potential sources of CO gas like water heaters or dryer vents. In addition, it is essential that you have the detector close to sleeping areas. The recommendation is to have one installed in your house’s bedroom/sleeping area. The carbon monoxide detector should be placed in the bedroom or not more than 10 feet away. For those sleeping in the basement of houses, the recommendation is to have a carbon monoxide detector inside the basement. 

Is a carbon monoxide detector necessary to have in each room?

It is typically not necessary to have carbon monoxide detectors in each room of your home. However, EPA (Environmental Protection Agency) states that at least a single unit should be available on each house floor. In addition, you also need to install a carbon monoxide alarm near sleeping areas, which may translate to having more than a single device on one floor of the house.

What are some of the common sources of carbon monoxide in houses?

Carbon monoxide is a gas that occurs naturally but becomes toxic at elevated levels. Everything that burns fuel based on carbon, be it a charcoal grill, gas grill, wood-burning fireplace, or propane-powered generator, produces carbon monoxide. Electricity-powered devices are the only household appliances that do not emit carbon monoxide. 

Most appliances burning fuel, including furnaces, dryers, and water heaters, do not pose any threat during normal operation. However, carbon monoxide may sometimes leak if the exhaust system or vent becomes blocked. Therefore, it is essential that you monitor and maintain such appliances and have carbon monoxide detectors nearby to alert you in the event of any leakages. 

How does a carbon monoxide alarm work?

The effects of carbon monoxide on your health vary according to the length of exposure and concentration of the gas – concentration here is measured in parts per million. Therefore, carbon monoxide detectors can be considered to be time-weighted alarms measuring the accumulation of carbon monoxide in houses. 

To start experiencing the harmful effects of carbon monoxide intoxication, you will need exposure to the gas at levels of 50 parts per million for eight hours. The alarm response time varies according to the carbon monoxide level in the air. For instance, an alarm will go off following three and a half hours of continuous exposure at 50 PPM levels, yet for 400 PPM continued exposure, it goes off after eight minutes. 

A carbon monoxide sensor will have a limited lifespan of between five and seven years, though some manufacturers claim their sensors can serve you for 10 years. In general, you are better off being on the safe side and replacing the alarm one or two years before its rated lifespan is supposed to end. US tests have revealed that an alarm over eight years old fails to detect carbon monoxide levels that are over 400 PPM. Note the test buttons that come with the devices do not test the actual sensor but are only a means of ensuring that the circuit works fine. 

Why does my carbon monoxide or smoke detector beep intermittently? 

If a smoke or carbon monoxide alarm beeps continuously and sporadically, make sure you check the instructions/user manual to learn what every particular beep pattern implies. This varies from one detector model and manufacturer to another. Below, we have examples of some common signals and what they mean.

  • Beeping once after 30 to 60 seconds could signify that the battery requires replacement or is probably installed incorrectly.
  • Multiple beeps per minute may mean that your detector is old and requires replacement.
  • Several consistent beeps and then a short pause may signify a threat detected by the device.

How do I stop the excessive beeping of my smoke and carbon monoxide detector?

Once you realize that your carbon dioxide or smoke detector keeps going off even without any sign of carbon monoxide or fire threat, the detector may have at least one of the following issues.

  • The device has a loose, incorrectly installed, or dying battery. Inspect the device and check its use-by date. 
  • The sensors of the alarm could be dirty. Try to wipe the alarm and create a habit of regularly dusting it after changing the battery or testing it.
  • You have the device installed close to an air vent or open window. Air currents can easily blow pollen or dust into the sensors. 
  • The area adjacent to the alarm might have high humidity. Hot shower steam can easily set off the alarm if you install it too close to your bathroom. 
  • You have the detector installed too close to your cooking equipment. For example, smoke or steam generated as you cook or bursts of heat from an open oven door can set off the smoke alarm when it is placed close to the stove. The instructions should indicate the optimal positioning of the gadget.
  • Your detectors need replacement. In your user manual, you will find information on the lifespan of your smoke or carbon monoxide detector.


When searching for the origin of the name Alex, you will find that it comes from the Greek name Alexandros which means ‘protector.’ Perhaps that is why protecting and defending the home environment is so important to Alex, the author of this website. It is clear to see that Alex is very passionate about teaching others how to protect themselves and their loved ones from intruders. That can also be because, in ancient scriptures, the name Alex means ‘to assist other men’ by providing them the means for protection. But that is not all for this resourceful person who loves to write, which can be seen in the many articles found on this website. He aims to teach others how to protect their homes and share his wisdom with them through his articles. It is easy to put the face and the name behind this instructive and informative website when you look at it that way. Alex has come a long way in the home security industry, which is proven by the knowledgeable advice in his posts. His love for writing comes from his love for reading, which he has done in spades from a very young age. An insatiable desire to understand things has driven Alex throughout his years of growing up in a home where knowledge was appreciated. Not just knowledge but also the way it can be obtained, and that is through reading, which has been passed on to him. Alex believes that people should be encouraged to do what they want and need to in life to have a better and happier existence. His passionate way of living life can be seen in everything he does, especially in how he shares information with others. The reason and drive behind every tip and piece of advice on this website comes from a good place.

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