1. Home
  2. Safety News
  3. The Best Carbon Monoxide (CO) Detectors of 2020

The Best Carbon Monoxide (CO) Detectors of 2020

From smart, energy-saving carbon monoxide detectors to ones that simply plug into an outlet, we found the best CO detectors available to keep your home and family safe.
Written by | Updated May 26, 2020
Best Overall
nest protect productGoogle Nest Protect
  • Smart home compatibility
  • Dual functionality
  • Smart home compatibility
  • Dual functionality
Best Voice Control
First Alert Carbon Monoxide DetectorFirst Alert OneLink
  • Amazon Alexa integration
  • Long battery life
  • Amazon Alexa integration
  • Long battery life
Best Value
Kidde Nighthawk
  • Affordable price tag
  • Digital display
  • Affordable price tag
  • Digital display

Bottom Line: Google Nest Protect offers more than basic CO protection

Nest was one of the first companies to combine a smoke alarm and carbon monoxide detection with smart tech. Because both hazards can be devastating, we like that you can get double the protection in one device. The addition of mobile alerts via the Nest app ensures you’ll get early warning of danger from carbon monoxide poisoning no matter where you are.

But you’ll pay for the Nest Protect’s extra protections—it starts around $120, which is a lot compared to a simpler carbon monoxide alarm that usually falls around $20.

Compare CO detectors and alarms

After hours of research and testing, we’ve found the best carbon monoxide detectors available. From basic battery operated to smart devices, you can find the top options here.

List Price
Smart Features
Digital Display
Smoke Sensor
Best Overall
Best Voice Control
Best Value
Home Security Pick
Easy Installation
Nest Protect First Alert OneLink Kidde Nighthawk SimpliSafe Carbon Monoxide Detector Kidde Battery-Operated
nest protect product First-Alert-Carbon-Monoxide-Detector kidde-nighthawk-plug-in-co-gas-alarm SimpliSafe CO detector Kidde Battery Powered CO Detector
$119.99 $172.86 $28.21 $49.99 $20.81
Yes
Yes
No
X
Yes
No
X
Yes
No
X
Yes
No
X
Yes
Yes
Yes
No
X
No
X
No
X
View on Kohl's View on Amazon View on Amazon Visit SimpliSafe View on Amazon

*Amazon.com prices as of 05/26/20 11:07 pm MST. See full disclaimer.

Our approach

To find the best carbon monoxide detectors, we compared features like smart features, installation ease, and detection accuracy. We also looked at user reviews to get a better idea of how these devices work first hand.

CO detector and alarm reviews

Google Nest Protect: best overall carbon monoxide detector

Best Overall
nest protect product

Nest Protect combines smoke and carbon monoxide detection and works with an app. When you download it, you can get alerts to your phone and even silence alarms if necessary. With state-of-the-art sensors for both fire and carbon monoxide, this alarm is one of the best for homeowners or renters.

You can’t change the batteries in this unit, so you’ll need to replace the whole thing once it expires. But at $120, Nest Protect is still a good value if it lasts for its full life expectancy of 10 years.

Learn more about the Nest Protect in our full product review.

Pros

  • Works with other smart home devices
  • Doubles as smoke detector
  • Comes with battery or hardwire capabilities
  • Features voice notifications

Cons

  • When the battery dies, you'll need a new alarm
Best Voice Control
First Alert Carbon Monoxide Detector

This smart smoke and carbon monoxide detector can do a lot. Using your home’s wifi, the alarms can talk to one another and synchronize to alert you if there is a gas leak or fire. You can also control it from your Apple device through an app, so you can silence the alarm or get notifications on your phone.

Onelink doesn’t have a battery compartment that you can access, so when it dies you’ll need to get a new CO detector. With a price tag over $200, that steep replacement cost might be more than some want to pay.

Pros

  • 10-year battery
  • Mobile app
  • Voice alarm
  • Syncing system
  • Built-in smoke alarm

Cons

  • Big price tag
  • When the battery dies, you'll need a new alarm

Kidde Nighthawk: best value

Best Value
Kidde Carbon Monoxide Detector

As the world’s largest fire safety product manufacturer, Kidde also produces high quality carbon monoxide detectors. While it’s not the cheapest option on our list, the Nighthawk packs in the most features for the best price.

With a digital display, you can read your home’s carbon monoxide levels easily. Plus, the device refreshes its data every 15 seconds so you’ll know if something isn’t right. If your device sounds, you’ll definitely hear it. This carbon monoxide alarm lets out an 85 db beep that’s as loud as a blender.

Pros

  • Affordable price
  • Digital display
  • Positive customer reviews
  • Backup battery

Cons

  • Not compatible with home automation
  • Hardwired only

SimpliSafe carbon monoxide detector: home security pick

Home Security Pick
SimpliSafe CO detector

SimpliSafe has a carbon monoxide detector among its arsenal of DIY home security devices. Like the other products from SimpliSafe, this CO detector is easy to install and notifies you of danger whether you’re home or not.

When its electrochemical sensor sniffs out dangerous levels of carbon monoxide, the alarm will sound and trigger the siren from the security system (making it impossible to ignore or sleep through). If you pair your SimpliSafe system with professional monitoring, you’ll be able to send first responders to your home to help with the situation.

The only downside is that you’ll need a SimpliSafe system to go with your CO detector. Learn more about SimpliSafe and other home security systems with carbon monoxide alerts.

Pros

  • Integrated with security system
  • Notifies you of danger remotely

Cons

  • No digital display
  • Doesn't sense smoke or heat

Kidde Battery-Operated: easy installation

Easy Installation
Kidde-Battery-Powered-CO-Detector

Kidde’s battery-operated CO detector is equipped with an electrochemical sensor, which is the best way to detect CO in your home. The digital display makes it easy to monitor levels of carbon monoxide. Plus, an 85 dB alarm ensures you won’t miss an alert.

You’ll appreciate the simple setup and operation of this device. All you have to do is pop in some batteries and mount it on the wall. But simplicity comes with drawbacks—there’s no smart home compatibility in this detector.

Pros

  • Digital display
  • Frequent readings
  • Easy installation
  • Affordable price

Cons

  • No home automation
  • No smoke detection

Types of carbon monoxide detectors

There are several types of carbon monoxide detectors available for purchase, some include multiple functions.

  • Dual-function: sense different threats like CO, smoke, and fire.
  • Digital: show you levels of carbon monoxide on a digital screen.
  • Smart: run diagnostics and sync with home automation apps.
  • Hardwired: wired into your home’s electrical grid, works unless the power goes out.
  • Battery-operated: basic sensing and display, needs batteries to operate.

Carbon monoxide detectors FAQs

Check out our full frequently asked questions page to learn more about carbon monoxide detectors.

What are the symptoms of carbon monoxide poisoning?

CO poisoning creates flu-like symptoms like dizziness, nausea, vomiting, headaches, confusion, or fainting.

How common is CO poisoning?

Every year, 400 Americans die from accidental carbon monoxide poisoning and 20,000 are admitted to the emergency room.

Who is most susceptible to CO poisoning?

Everyone is susceptible to carbon monoxide poisoning, but children, older adults, people who are physically ill, and pets are more likely to be affected by CO.

What do I do I get CO poisoning?

If you’re at home, get out of the house and call 911. CO poisoning doesn’t always hit suddenly and doesn’t leave your system quickly, so it’s a good idea to seek medical attention as soon as you can.

What is a carbon monoxide detector?

Carbon monoxide detectors work like smoke detectors, but detect levels of carbon monoxide instead.

These are the most common sensors in CO detectors:

  • Biomimetic detectors use color-changing gels that absorb carbon monoxide which triggers the alarm.
  • Metal oxide semiconductors have silica chips that detect CO and send electrical signals to trigger an alarm.
  • Electrochemical sensors use electrodes in chemical solutions that sense changes in electrical currents when carbon monoxide is present, and they sound an alarm.

Most professionally monitored security systems come with a CO detector. Check out our top security providers to see which home security systems include CO detectors with their monitoring plans.

Where should I install carbon monoxide detectors?

Put a carbon monoxide detector outside every separate sleeping area in your home, your kitchen, basement, and garage. We recommend finding an area far enough from the carbon monoxide source, but close enough to the areas you and your family normally occupy.

Check out our full guide on where to install your own carbon monoxide detectors.

How to maintain a carbon monoxide detector

Most carbon monoxide detectors last an average of five years. Although the product’s lifetime will vary depending on your make and model, you can still get the most out of your detector by wiping it down weekly to keep it clean from dust and debris.

Just like your smoke detectors, it’s a good idea to test your CO detector monthly. Start by pressing the “test” button to ensure the siren works. If your detector is older, you can purchase a carbon monoxide meter to find out if your detector is still fully functional. If the carbon monoxide sensor doesn’t go off when you test it, it’s probably time to buy a new one.

Know what can make carbon monoxide gas

chart-common-causes--of-carbon-monoxide-poisoning

Carbon monoxide (CO) has been called the “silent and invisible killer” because it doesn’t have a smell, color, or taste. It’s one of the most prevalent causes of death due to poisoning in America. Any time you burn something—like gasoline, natural gas, wood, oil, propane, or charcoal—carbon monoxide is released into the air.

In outdoor spaces, this usually isn’t a health hazard because there is enough area for the CO to dissipate, so particles never amount to a toxic level. The danger comes when carbon monoxide is released in a contained area like your home, RV, or garage.

Anything that burns will create carbon monoxide. It’s not just your stove, fireplace, or grill either. Here are some of the things that can create carbon monoxide when turned on:

  • Appliances
  • Gas grills
  • Gas stoves
  • Gas or oil-burning furnaces
  • Fuel-burning water heaters
  • Non-electric space heaters
  • Tools
  • Snowblowers
  • Lawnmowers
  • Pressure washers
  • Generators
  • Non-electric cars, trucks, and boats
  • Chain saws

Know what to do and what not to do

Lighting a fire in your fireplace is okay if it’s properly ventilated. However, if you do the following, you could cause dangerous levels of carbon monoxide to build in your home.

Do

  • Always vent gas appliances properly
  • Get your chimney checked annually to ensure proper ventilation

fireplace illustration

Don’t

  • Never burn gas grills inside your home
  • Don’t use your gas stove/oven for heating
  • Don’t leave the car running with the garage door closed
  • Don’t patch or seal vent pipes with tape or unapproved products or carbon monoxide could leak into your home
  • Don’t ever burn charcoal inside
  • Never run a generator in your home or within 20 feet of your home’s doors, windows, and garage
  • Don’t turn on your car if the tailpipe is blocked (by snow or anything else)

*Amazon.com list price as of 05/26/20 11:07 MST. Product prices and availability are accurate as of this date/time indicated and are subject to change. Any prices and availability information displayed on Amazon at the time of purchase will apply to the purchase of this product. Safewise.com utilizes paid Amazon links.

Certain content that appears on this site comes from Amazon. This content is provided “as is” and is subject to change or removal at any time.

Written by Rebecca Edwards

Rebecca is the lead safety reporter and in-house expert for SafeWise.com. She has been a journalist and blogger for over 25 years, with a focus on home and community safety for the past six. Rebecca spends dozens of hours every month testing and evaluating security products and strategies. Her safety expertise is sought after by publications, broadcast journalists, non-profit organizations, podcasts, and more. You can find her work and contributions in places like TechCrunch, The Washington Post, The Chicago Tribune, HGTV, MSN, and an ever-growing library of radio and TV clips. Learn more

Share this article.
  • http://www.reviews.org Scott T.

    What do you think of our picks for best carbon monoxide detectors and alarms? Is there something we missed, or what else would you like to know?

    • PLK

      How many different units were tested? Are the results based on testing, i.e. using the UL standard or just the features offered?

  • joeandmilly

    Nest is compatible with both Android and Apple, not sure why she wrote only compatible with Apple. nest is owned by Google, which produces the Android OS along with Google Home

    also First Alert is compatible with both iOS and Android as well.

    • http://www.reviews.org Scott T.

      Nice catch! We try to keep things updated, but sometimes tech moves faster than we do. We’ll update it!

  • Sumit

    Check: The Home Security Solution Blog

  • Sumit

    to know more about the digital home security solution check: The Home Security Solution Blog

  • http://gspirits.com/ Zod

    I purchased the FirstAlert C0400 for use in my basement that has a gas fired furnace and water heater. I liked that it was small and simple. After about 2 weeks of use, the thing started giving a low battery chirp.. ok, just swap out the battery! 2 weeks later, I’m getting a low battery chirp again. What? I out in a fresh Duracell! Popped out the battery and tested the voltage with my Fluke meter….7.75 volts. I still had the old battery. I tested that. 7.75 volts. My conclusion is that this thing eats batteries! At one battery every 2 weeks, that 26 batteries a year…at $3/battery, that’s $78 a year..plus the hassle of popping the batteries in and out! No! This is not a good thing! That plug-in Kidde for $30 looks to be the better value just because it is plug-in!

    • Rebecca Edwards

      Thank you so much for sharing your experience. We will add your notes to our testing and customer experience database and check for this phenomenon when we re-test and re-evaluate our rankings. Your input is valuable and so helpful to others looking to make the best choice for a CO detector in their home. Thanks, again!

    • Rebecca Edwards

      Thanks again for sharing this information. We looked into this and found that others are having the same problem. It looks like the manufacturing date might be the problem. Many have gotten units that were manufactured 10 years ago, which means the product is likely expired. We’re so sorry this happened, and we’ll add an update to our page to let others know.

  • homenow.io

    Kidde consistently makes great products!