The Nest CO Detector

The 10 Best Carbon Monoxide Detectors

One of the most important life-saving security products you can have in your home is a carbon  monoxide detector. Carbon monoxide is a colorless, odorless gas that causes 450 deaths per year and tens of thousands of trips to the emergency room in the United States. Finding the best carbon monoxide detector for you depends on the features you want, how it’s powered and your budget. Thankfully, there are some great options out there to choose from. These are the ten best carbon monoxide detector options on the market right now.

The SecurityNerd Picks for the 10 Best CO Detectors

Best Overall: Nest Protect

You may know Nest for creating the revolutionary thermostat that changed the way people heat and cool their homes. But Nest, owned by Google, also has the best carbon monoxide alarm option on the market. It not only alerts you to carbon monoxide, but it also acts as a smoke alarm. A voice alarm also lets you know what type of emergency is happening before the alarm sounds. It works seamlessly with other Google products, which makes it a great addition to your home ecosystem. (You can also check out our full review of the Nest Protect.)

  • Tech features: Smart alerts, built-in smoke detector, night light, battery and wired versions available, smart home integration, auto testing, mobile app
  • Security plan: Not required

Nerd Pros

  • Auto testing: Don’t worry if you forgot to test your carbon monoxide alarm this month. Nest Protect tests itself, while self-monitoring its battery life.
  • Dual functionality: This is more than a carbon monoxide detector. It will also alert you to smoke in the home via a siren and a mobile app. It’s pricier than many carbon monoxide detectors, but you get two functions in one price.
  • Night light: The night light can be especially useful if you tend to wake up at night to grab a drink or go to the bathroom. The “pathway” light comes on automatically and gives you just enough night to be able to see your surroundings without turning on bright lights.

Nerd Cons

  • Price: Buying the best carbon monoxide detector comes with a higher price tag than its competitors. You get what you pay for, but the price may be a deterrent for customers looking not to spend a lot of money.
  • False alarms: Nest carbon monoxide alarm customers have complained about false alarms. However, our SecurityNerd has not had a problem with false alarms with this product.
Google S3000BWES Nest Protect Alarm-Smoke Carbon Monoxide Detector, 1, White
  • Smoke detector and carbon monoxide detector that speaks up in a friendly voice to give you an early warning when there’s smoke or CO in...
  • Split Spectrum Sensor looks for both fast burning and smoldering fires and tells you where the danger is
  • Get phone alerts so you know something’s wrong even when you’re away from home[1]
  • CO detector looks out for carbon monoxide and tells you where it’s located
  • With App Silence, you can silence the smoke alarm with your phone in the Nest app when there’s only a little smoke

Best for Use with Alexa: First Alert Onelink

The Onlink carbon monoxide alarm is also a carbon monoxide detector and smoke detector in one. First Alert has a solid track record in the fire safety industry, and you can be assured you’re getting a high-quality product.

One of the standout features with this carbon monoxide alarm is its seamless functionality with Alexa voice control. You’ll be able to ask Alexa to check up on your alarm to make sure it’s working.

  • Tech features: Smart alerts, smoke detector built-in, battery and wired versions available, smart home integration, mobile app, easy battery changes
  • Security plan: Not required

Nerd Pros

  • Smart home options: This carbon monoxide detector works with Alexa and Apple HomeKit, making it a favorite for the smart home aficionados out there. You can also receive alerts from your smart phone in case of an emergency.
  • Dual functionality: You’ll get two functions in one with this carbon monoxide detector, as it can also detect smoke in your home.
  • Mobile and voice alarms: If your carbon monoxide alarm senses an issue, you can receive an alert through your app, and also hear a voice alert and siren.

Nerd Cons

  • Price: It’s one of the best carbon monoxide detector options on the market, and it also has a hefty price tag.
  • Glitchy app: Onelink customers have complained of issues with the mobile app, including setup issues and lagging.
Onelink Smoke Detector and Carbon Monoxide Detector | Hardwired | First Alert
  • SMOKE + CO DETECTION 2-in-1 smart smoke and carbon monoxide alarm alerts you to both types of danger in your home, with a photoelectric...
  • MOBILE + VOICE ALERTS Alarm sends emergency notifications, via your phone, while voice alerts tell you the type and location of danger
  • A HOME SAFETY NETWORK + ALEXA Interconnects with existing traditional hardwired alarms and other Onelink devices (sold separately) to create...
  • HARDWIRED + BATTERY BACKUP Hardwired alarm includes a 10-year sealed battery backup for protection in power outages; for maximum protection,...
  • COMPATIBILITY Compatible with Apple HomeKit; can be used on both Apple and Android devices

Best Security System Pick: SimpliSafe CO Detector

SimpliSafe is known for offering high-quality home security products at DIY prices. If you’re looking for a home security system with a mix of value and quality, along with a reliable carbon monoxide detector, SimpliSafe is a great way to go. This wireless option can also give you extra peace of mind when you have the choice of adding professional monitoring. But it’s important to note that you must have a Simplisafe security system hum to use this carbon monoxide detector.

  • Tech features: Smart alerts, siren, electrochemical sensing technology, easy installation
  • Security plan: Not required, but you must have a SimpliSafe hub to use

Nerd Pros

  • Price: This carbon monoxide detector has an affordable price tag, which is an attractive feature if you’re looking to save some cash.
  • Smart alerts: Customers can receive alerts via the SimpliSafe app if there is any carbon monoxide issue.
  • Professional monitoring option: Although you aren’t required to have professional monitoring with this carbon monoxide alarm, if you purchase it, authorities will automatically be dispatched to your home if the alarm goes off.

Nerd Cons

  • No digital display: If you want to see what your carbon monoxide levels are reading at all times, you won’t have that chance with this system. It is bare bones, but then again so is the price tag.
  • No fire alarm: You can purchase a smoke alarm separately from SimpliSafe, but there is not currently a two-in-one product.
SimpliSafe SSES1 Carbon Monoxide Sensor
  • Easy install. Comes with preinstalled 3M Command brand adhesive for a peel and stick installation
  • Triggers an alarm in the presence of high concentrations of Carbon Monoxide
  • Wireless and easy to program -- take it with you if you move

Best Bargain: Kidde #KM-COSM-IBA

Kidde has been around for over 100 years manufacturing fire safety equipment. It’s one of America’s largest manufacturers of smoke detectors. If you’re in the market for a no-nonsense smoke detector, or even a unit with carbon monoxide detection as well, Kidde provides an array of affordable options with added benefits for your home.

  • Tech features: Tamper-resistant, easy installation, memory announcements, 2-in-1 fire and carbon monoxide detection, LED indicators, talking alarm, siren
  • Security plan: None

Nerd Pros

  • Price: Although you can find a carbon monoxide alarm at a similar price, this one has impressive features like LED indicators at a low price point.
  • Dual functionality: You’ll be alerted to carbon monoxide as well as smoke in your home. This smoke detector will flash red when dangerous levels of carbon monoxide have been detected in your home, so you know what the problem is.
  • Verbal warnings: In addition to a siren, your alarm will also warn you with a voice before the alarm goes off to tell you exactly the emergency.

Nerd Cons

  • No app: You will be sacrificing some functionality in order to get a bargain. This carbon monoxide detector will not allow you to get smart alerts, or control the system from your phone.
  • No digital display: You may find similar carbon monoxide alarm options at other price points that have a digital display. This one does not have the bells and whistles, but it is affordable and reliable.
Kidde KN-COSM-IBA Hardwire Combination Smoke Carbon Monoxide Detector Battery Backup Voice Warning Interconnectable
  • Smart Interconnect-Interconnects up to 24 Kidde devices (of which 18 can be initiating), Battery Backup (2-AA batteries included)-Provides...
  • Humidity range: 10%-95% relative humidity, non-condensing. Battery Lockout System-The battery door will not close unless the batteries are...
  • Peak Level Memory-Announces “CARBON MONOXIDE PREVIOUSLY DETECTED” if alarm has detected a CO level of 100ppm or higher since it was last...
  • Ionization Sensor Technology-Ideal for detecting fast flaming and other types of fires, est Button Functions: – Tests the unit for proper...
  • Green LED-Illuminates to indicate the unit is receiving AC power. Flashes once every 60 seconds to indicate battery only mode. Flashes once...

Best for Senior Citizens: First Alert BRK SC7010B

First Alert is a company with a long track record in fire safety, which should make you feel comfortable with buying this carbon monoxide alarm complete with a built-in fire alarm. This unit comes at an affordable price with a unique selling point: it’s ideal for senior citizens or those with hearing issues because of its loud voice alerts. While it may not have the smart home features you’ll find in a more expensive model, it will get the job done.

  • Tech features: Verbal warnings, dual functionality, alarm, voice alerts, battery backup
  • Security plan: None

Nerd Pros

  • Verbal warnings: Before any alarm goes off, you will hear a loud voice tell you the emergency it detects.
  • Dual functionality: This First Alert model will alert you to smoke in your home as well as carbon monoxide.
  • High frequency alarm: The alarm frequency on this First Alert model is loud, but also has a frequency that makes it easier for some people with hearing impairment to hear.

Nerd Cons

  • No smart home integrations: You will not be able to control this carbon monoxide alarm from a smartphone, nor integrate it with any type of smart home option.
  • No digital display: This is more like your traditional carbon monoxide detector, without the bells and whistles you may see with more expensive options.
Sale
First Alert BRK SC7010B Hardwired Smoke and Carbon Monoxide (CO) Detector with Photoelectric Sensor
  • Keep your family safe with this hardwired smoke and carbon monoxide alarm; The battery backup means constant monitoring, even if there's a...
  • Features electrochemical Carbon Monoxide sensing technology as well as a photoelectric sensor equipped with Optipath 360 technology that...
  • In case of danger, the loud spread spectrum alarm is designed to be heard easily by even those with some hearing issues
  • Can connect to other compatible BRK or First Alert detectors, to ensure all alarms will sound when threat is detected
  • 10 year limited warranty; Equipped with end of life signal chirp, so you know when it's time to replace the unit for your safety

Best Hardwired Option: First Alert BRK CO5120BN

This carbon monoxide detector option by First Alert detects the deadly gas and emits a loud siren. This hardwired option means you don’t have to worry about changing batteries regularly—although you should still test it once a month. The best part about this model is the microprocessor that cuts down on pesky false alarms.

  • Tech features: Electrochemical sensor, microprocessor to cut down on false alarms, hardwired, siren
  • Security plan: None

Nerd Pros

  • Price: This is a solid carbon monoxide option for budget-conscious consumers.
  • Fewer false alarms: Thanks to its microprocessor, this detector is able to cut down on false alarms.

Nerd Cons

  • No smart home integrations: Customers don’t have any smart home options with this carbon monoxide detector. There is no voice activation or smartphone app.
  • No smoke detector: While many carbon monoxide detectors also have a smoke detector built-in, this one does not. So you’ll need a separate smoke detector.
  • Sensor issues: Users report the sensor can be difficult to get into the base upon installation.
First Alert BRK CO5120BN Hardwired Carbon Monoxide (CO) Detector with Battery Backup
  • 120 volt hardwired carbon monoxide alarm wires directly into your home's electrical system
  • Electrochemical sensor accurately detects carbon monoxide
  • Microprocessor controlled to minimize false alarms
  • Easy to access battery drawer; 9 volt battery included
  • Can integrate with up to 18 compatible devices for extended coverage; Emits T3 Pattern

Best Versatility: Kidde Nighthawk #KN-COEG-3

This Kidde Nighthawk adds an extra level of versatility to a carbon monoxide alarm—it also provides natural gas detection which could keep your home safe in event of a gas leak. For under $40, it’s a powerful tool for your home.

  • Tech features: Explosive gas sensor, digital display, peak level memory, test/reset button, easy installation
  • Security plan: None

Nerd Pros

  • Dual functionality: Not only do you get a carbon monoxide alarm, you’ll also get the functionality of a natural gas detection system to protect you on two fronts.
  • Digital display: Customers are able to see readings in real time thanks to an easy-to-see display.
  • Peak level memory: Press one button and you’ll be able to check out the peak level of carbon monoxide (if any) that was detected in your home.

Nerd Cons

  • No smart home integrations: You can’t get smart alerts, or control this carbon monoxide detector from your smartphone.
  • No smoke detector: Although this has a natural gas detection option, it doesn’t have a simple smoke alarm. You’ll need a separate one of those.
Kidde AC Plug-in Carbon Monoxide and Explosive Gas Detector Alarm | Nighthawk Sensor Technology | Model # KN-COEG-3
  • Protects you and your family from two deadly threats: Carbon monoxide and explosive gas.
  • Sounder alarm – The KN-COEG-3 offers a loud 85-decibel pulsing alarm that will sound to alert you to a potential problem.
  • Digital display - Displays the level of carbon monoxide the unit is sensing.
  • Peak level memory - Recalls the highest CO concentration detected
  • Test/reset button - Tests unit’s electronic circuitry operation and allows you to immediately silence the alarm

Best Battery Life: First Alert CO710

This is the best carbon monoxide detector option for you if you don’t want to worry about battery issues, or changing them regularly. This battery-powered option lasts for 10 years, according to the manufacturer, at a cheap price. It’s designed to sit on a tabletop, but you can also hang it on the wall if you’d prefer.

  • Tech features: Digital display, temperature display, 10-year lithium battery, peak level memory feature, end-of-life signal chirp, siren
  • Security plan: None

Nerd Pros

  • Simple installation: There is no hardwired version here, so you can either put the carbon monoxide alarm on a tabletop like a clock, or hang it on a wall with two drilling mounts provided.
  • Digital display: Not only will you be able to see the carbon monoxide levels on display, it also shows the temperature.
  • Best battery life: This built-in lithium battery lasts for 10 years, and begins an end-of-life chirp to let you know when it’s time to get another one.

Nerd Cons

  • No smart home integrations: There is no smart home option or app with this product.
  • No smoke alarm: There is no dual functionality with this carbon monoxide detector, as it does not detect smoke.
First Alert Carbon Monoxide Detector with 10-Year Battery and Digital Temperature Display, CO710
  • Keep your family safe with this easy to use digital-display, 10-Year battery operated carbon monoxide alarm; Battery powered alarms provide...
  • Easy-to-read backlit digital display shows temperature and CO concentration; Peak Level feature displays the highest concentration of carbon...
  • Built-in 10-year lithium battery offers continuous protection for the life of the carbon monoxide detector
  • A loud 85-decibel alarm sounds when CO levels reach dangerous levels
  • 10-year limited warranty; Equipped with end-of-life signal chirp, so you know when it’s time to replace the unit for safety

Most User-Friendly: Kidde KN-COPP-B LPM

If you’re looking for a simple, user-friendly carbon monoxide detector, this Kidde model is perfect. Easy-to-see digital display along with buttons to show peak carbon monoxide levels along with a test button make it simple to use for anyone. LED lights also let you know if there’s an issue, with a red LED light flashing in case of an emergency, which can come in handy for users with impaired hearing.

  • Tech features: Digital display, siren, battery-operated, test/retest buttons, LED lights, peak level memory
  • Security plan: None

Nerd Pros

  • Price: At just over $20, this a solid carbon monoxide detector without hard-to-use features. It’s simple, but it also gets the job done.
  • Digital display: You’ll be able to see if there is a carbon monoxide reading just by looking at the detector.
  • LED lights: See a green LED light when the product is working properly, and a red LED light flashing if there is a dangerous level of CO, along with a siren.

Nerd Cons

  • No smart home integrations: If you’re interested in home automation, this is not the best carbon monoxide detector for you. There is no way to control it remotely.
  • No smoke alarm: There is no dual functionality with this carbon monoxide detector, as it does not detect smoke.
Kidde Carbon Monoxide Alarm Detector | Digital Display | Battery Operated | Model KN-COPP-B-LPM
  • Digital Display - Displays the level of carbon monoxide the unit is sensing. Shows CO level in PPM (parts per million). Updates digital...
  • Battery Operated - Provides best protection during power outages. Battery Safeguard makes it difficult to close the cover without batteries...
  • Test/Reset Button - Tests unit’s electronic circuitry & horn and resets the unit during alarm. Tests CO alarm circuit operation and allows...
  • LED's - Green LED for normal operation, Red LED for alarm. Temperature range 40˚F (4. 4˚C) to 100˚F (37. 8˚C). Sensor: Electrochemical
  • Provides peace of mind against the silent killer and a digital display

Most Flexible Installation: Kidde KN-COPP-3

No matter where you want to install this hardwired model with a battery backup, you’ll be able to find a spot thanks to its incredible versatility. Plug it right into an outlet, use a 6-foot extension cable, or simply keep it on a table nearby. For under $30, you’ll get a carbon monoxide detector with 10 years of life.

  • Price: $29.64 on Amazon
  • Tech features: Multiple installation options, peak level button, test buttons, LED lights, battery backup
  • Security plan: None

Nerd Pros

  • Versatility: You don’t have to necessarily install this carbon monoxide alarm like a traditional one. Plug it into an outlet on the wall, keep it on the shelf, or use an extension cord to mount wherever you’d like.
  • LED lights: You’ll see a green light when it’s operating properly, and a red LED light when there is carbon monoxide detected.

Nerd Cons

  • No smart home integrations: There’s no smart home app or any opportunity for any home automation options with this model.
  • No smoke alarm: You’ll have to use a separate smoke alarm, because this one does not provide dual functionality.
Sale
Kidde Nighthawk Plug-In AC/DC Carbon Monoxide Alarm Detector with Digital Display KN-COPP-3
  • Peak level button – Displays the peak CO level recorded by the alarm since it was last reset or unplugged
  • Test button functions – Tests the unit for proper operation and resets the carbon monoxide alarm
  • LED operation – Blinking dot in lower right corner of display denotes normal operation
  • Ten years after the initial power up, this alarm will “beep” two times every 30 seconds to indicate that it is time to replace the...
  • Note: This CO alarm is not battery operated. However, these alarms are equipped with 9 volt battery backup – the 9 volt battery is to...

What to Consider Before Buying a Carbon Monoxide Detector

Wired vs. wireless

A wireless carbon monoxide detector allows flexibility in where you place it, but it also means it’s battery operated. You’ll need to be diligent on changing batteries with a wireless option.

Design and features

Are you looking for a sleek option to fit into your décor, or a traditional carbon monoxide detector that doesn’t need to look a certain way? Perhaps you need one that also has a smoke detector, or an especially loud siren for the hearing impaired. It’s also important to think about whether you are looking for a product with smart home options to control remotely.

Security system or smart home compatibility

You may want to purchase a carbon monoxide detector through your existing security company if you already have one. Or, if you’re an Apple, Alexa, or Google user, there are different detectors that work better with each of them.

The Bottom Line on Carbon Monoxide Detectors

A carbon monoxide detector is one of the single most important home security products you can add to your house. Before purchasing a carbon monoxide alarm, you should decide if you want smart home or security system integration, and whether your unit should be battery operated or hardwired. Whether you’re looking for a high-tech, sleek option you can control from your smart phone, or a bare bones detector you can rely on, there’s a solid option that can keep you or your family safe, no matter your budget.

This article has been reviewed and approved by Officer Banta.

Officer James Banta

Officer Banta is the official SecurityNerd home security and safety expert. A member of the Biloxi Police Department for over 24 years, Officer Banta reviews all articles before lending his stamp of approval. Click here for more information on Officer Banta and the rest of our team.

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