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The Best Carbon Monoxide Detector - 2021

Last updated on July 18, 2019

We looked at the top 10 Carbon Monoxide Detectors and dug through the reviews from 53 of the most popular review sites including and more. The result is a ranking of the best Carbon Monoxide Detectors.

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Our Picks For The Top Carbon Monoxide Detectors

Show Contents
Our Take
Experts Included
Pros
Cons
  The Best Overall
10.2

First Alert Carbon Monoxide Alarm

Don't Waste Your Money Seal of Approval

First Alert

Carbon Monoxide Alarm

Overall Take

Connects to DevicesConnects with other First Alert devices in your home. Can also tell you where the issue is in your house.

Experts Included
DWYM Home Experts plus New York Times Wirecutter, Tuck, The Spruce, Business Insider, Consumer Search. Along with user reviews from Amazon.
Pros
" These photoelectric devices with voice alerts can interconnect and allow you to identify threats by location."
Cons
"Some reviewers say they have had issues with false alarms or the units not linking properly, however. Warranty is seven years."
  The Best Value

Alert Plus Carbon Monoxide Alarm Detector

Alert Plus

Carbon Monoxide Alarm Detector

Overall Take

Increasing AlertsThis detector offers increasingly quick alerts as the carbon monoxide levels rise.

Experts Included
DWYM Home Experts plus Safety, Peak Home Security. Along with user reviews from Amazon.
Pros
" Flashes a bright LED light with a loud and clear 85-decibel alarm if rising carbon monoxide levels are detected"
Cons
"The beeping sound is not loud enough even with new batteries"

Nest Protect Smoke and Carbon Monoxide Alarm

Nest

Protect Smoke & Carbon Monoxide Alarm

Overall Take

High-Tech DetectorThis combo carbon monoxide detector and smoke detector hooks up to your home's Wi-Fi and can be monitored from an app.

Experts Included
DWYM Home Experts plus Tom’s Guide, BestReviews, Trusted Reviews, Digital Trends, New York Times Wirecutter, Tuck and 3 more. Along with user reviews from Amazon and Target.
Pros
" The Nest Protect uses a split-spectrum sensor that Nest says is good at detecting both slow-smouldering fires as well as fast-burning ones."
Cons
"CO readings not given in PPM"

Kidde Nighthawk AC Plug-in Operated Carbon Monoxide Alarm with Digital Display KN-COPP-3

Kidde

Nighthawk Carbon Monoxide Alarm

Overall Take

Loud AlarmA loud alarm and top-notch detection make this a safe bet for your home.

Experts Included
DWYM Home Experts plus Tuck, The Spruce, SafeWise, Review Lab, Best Consumer Reviews, Safety and 1 more. Along with user reviews from Walmart.
Pros
" The Kidde Nighthawk’s digital display shows the current CO levels in the house, with sensitivity as low as 11 ppm."
Cons
"Display accuracy is good, though not top-notch"
Don't just take for granted what one reviewer says. Along with our own experts, DWYM analyzes the top expert reviews of the leading products and generates a score you can actually trust.
17

Products Considered

We identified the majority of the carbon monoxide detectors available to purchase.
10

Products Analyzed

We then selected the leading and most popular products for our team to review.

View All Product Rankings

53

Expert Reviews Included

In addition to our expert reviews, we also incorporate feedback and analysis of some of the most respected sources including: Safety, Peak Home Security, Tuck, The Spruce, SafeWise.

30,632

User Opinions Analyzed

We also incorporate user reviews from the leading retailers including

Our experts reviewed the top 10 Carbon Monoxide Detectors and also dug through the reviews from 53 of the most popular review sites including and more. The result is a ranking of the best of the best Carbon Monoxide Detectors.

DWYM is your trusted roduct review source. Our team reviews thousands of product reviews from the trusted top experts and combines them into one easy-to-understand score. Learn more.

Don't Waste Your Money Seal of Approval
Look for the DWYM seal for products that are the best in their category.

The Best Overall

First Alert Carbon Monoxide Alarm


Our Expert Score

10.9
5 expert reviews

User Summarized Score

8.6
545 user reviews

Our Take

Electrochemical sensors help the First Alert Carbon Monoxide Alarm detect both low and high carbon monoxide levels. If you have other First Alert devices, you can connect your carbon monoxide detector to those for comprehensive home protection. The First Alert Carbon Monoxide Alarm also provides location awareness to let you where the issue is in your home.

What other experts liked

These photoelectric devices with voice alerts can interconnect and allow you to identify threats by location.
- New York Times Wirecutter
The Voice Alarm is its standout feature. You can program up to 11 locations within your home, and the alarm will verbally alert you precisely where the danger is.
- Tuck
It uses electrochemical sensors that get top marks from experts for recognizing both high and low carbon monoxide levels, and testers say it has a very accurate display.
- The Spruce
March 1, 2019 | Full review
The First Alert Smoke and Carbon Monoxide Alarm is a terrific solution because it has an electrochemical CO sensor and is interconnected so it alerts the other connected alarms when there are dangerous conditions
- Business Insider
The SCO501CN-3ST uses radio technology to set up a wireless network with other First Alert interconnectable alarms -- smoke, CO or combination -- without the complications that a hardwired interconnected alarm system would entail
- Consumer Search

What other experts didn't like

Some reviewers say they have had issues with false alarms or the units not linking properly, however. Warranty is seven years.
- The Spruce
March 1, 2019 | Full review
Complaints of false alarms
- Business Insider
You might need to experiment a little with alarm location to make sure that each unit is within range of at least one other interconnected alarm
- Consumer Search

The Best Bang For Your Buck

Alert Plus Carbon Monoxide Alarm Detector

Our Expert Score

9.0
2 expert reviews

User Summarized Score

9.2
179 user reviews

Our Take

Once you reach 50 ppm, you'll get an alert within 60 to 90 minutes with the Alert Plus Carbon Monoxide Alarm Detector. Those alerts increase in time delay at higher ranges. If you reach 100 ppm, you'll get an alarm within 10 to 40 minutes. This detector is battery-powered, so you'll need to make sure you keep fresh batteries installed at all times.

What other experts liked

Flashes a bright LED light with a loud and clear 85-decibel alarm if rising carbon monoxide levels are detected
- Safety
It also has an LCD display showing you a clear level of carbon monoxide concentration around you. Depending on the level of CO being detected, this device will alarm within 60-90 minutes for 50ppm, within 10-40 minutes for 100ppm and within 3 minutes for 300ppm.
- Peak Home Security

What other experts didn't like

The beeping sound is not loud enough even with new batteries
- Peak Home Security

Overall Product Rankings

First Alert Carbon Monoxide Alarm

1. First Alert Carbon Monoxide Alarm

Overall Score: 10.2
Reviews Included: 8

Alert Plus Carbon Monoxide Alarm Detector

2. Alert Plus Carbon Monoxide Alarm Detector

Overall Score: 9.1
Reviews Included: 3

Nest Protect Smoke and Carbon Monoxide Alarm

3. Nest Protect Smoke and Carbon Monoxide Alarm

Overall Score: 9.4
Reviews Included: 11

First Alert Dual-Power Carbon Monoxide Detector Alarm

5. First Alert Dual-Power Carbon Monoxide Detector Alarm

Overall Score: 9.1
Reviews Included: 9

Kidde Sealed Lithium Battery Power Carbon Monoxide Alarm

6. Kidde Sealed Lithium Battery Power Carbon Monoxide Alarm

Overall Score: 9.0
Reviews Included: 4

First Alert Smoke Alarm

7. First Alert Smoke Alarm

Overall Score: 8.5
Reviews Included: 9

Sensorcon Carbon Monoxide Detector

8. Sensorcon Carbon Monoxide Detector

Overall Score: 8.2
Reviews Included: 7

Kidde Battery Operated Carbon Monoxide Alarm

9. Kidde Battery Operated Carbon Monoxide Alarm

Overall Score: 7.7
Reviews Included: 8

Roost PP3 (9v) Specialty Battery

10. Roost PP3 (9v) Specialty Battery

Overall Score: 7.1
Reviews Included: 7

Our Carbon Monoxide Detector Findings


First Alert Carbon Monoxide Alarm

What We Liked: Electrochemical sensors help the First Alert Carbon Monoxide Alarm detect both low and high carbon monoxide levels. If you have other First Alert devices, you can connect your carbon monoxide detector to those for comprehensive home protection. The First Alert Carbon Monoxide Alarm also provides location awareness to let you where the issue is in your home.

Kristin Forte/Simplemost Media


Alert Plus Carbon Monoxide Alarm Detector

Best Value

What We Liked: Once you reach 50 ppm, you’ll get an alert within 60 to 90 minutes with the Alert Plus Carbon Monoxide Alarm Detector. Those alerts increase in time delay at higher ranges. If you reach 100 ppm, you’ll get an alarm within 10 to 40 minutes. This detector is battery-powered, so you’ll need to make sure you keep fresh batteries installed at all times.

Kristin Forte/Simplemost Media


Nest Protect Smoke and Carbon Monoxide Alarm

What We Liked: The Nest Protect Smoke and Carbon Monoxide Alarm is a unique type of carbon monoxide detector, also providing smoke detection. This is a smart alarm, which means it hooks up to your home’s Wi-Fi and lets you monitor your CO levels using an app. If you do have an evacuation, the Nest detector will light a path to help you get out even if it’s late at night.

Kristin Forte/Simplemost Media

Our Carbon Monoxide Detector Buying Guide

It’s known as the silent killer. An odorless, colorless gas, carbon monoxide seeps into a home and gradually poisons its occupants, killing an estimated 400 people per year. Symptoms are commonly mistaken for the flu, leading sufferers to delay getting treatment until it’s too late.

Kristin Forte/Simplemost Media

The Centers for Disease Control says one of the best ways to prevent carbon monoxide poisoning is to install a detector in your home and update your batteries at least every six months. You’ll need to place it close to your master bedroom to ensure you hear any late-night alerts and replace the detector at least every five years.

But the first step in protecting your family against carbon monoxide is to choose a good detector. There are many on the market that will do the job, but some features are more important than others. You can find a detector that will display carbon monoxide levels at all times, giving you reassurance it’s actively monitoring the safety of the air you’re breathing.

Kristin Forte/Simplemost Media

If you don’t already have functioning smoke detectors in your home, you may want to consider a unit that will protect your home against fire as well as carbon monoxide. You may also want to consider purchasing a device that links up to smoke detectors so that all of your devices communicate with each other.

You’ll notice some carbon monoxide detectors are wired while others are battery-powered. If you choose a wired model, make sure it has a battery backup that kicks in if the power goes out. Whether it’s battery-powered or wired, though, you’ll need to change the batteries at regular intervals. Experts recommend updating the batteries in your smoke and carbon when you adjust your clocks for Daylight Savings Time to keep the task easy to remember. However, you can buy detectors that will alert you when the battery is low.

Kristin Forte/Simplemost Media

DWYM Fun Fact

In addition to buying a carbon monoxide detector and maintaining it, there are a few other things you can do to keep your family safe. Oil, wood and gas furnaces are common sources of CO, as are gas stoves or dryers. If you use a gas or oil water heater, candle or a gas lantern, you may also be at risk. One important preventive measure you can take is to schedule regular inspections of any gas, oil or coal-burning appliance. You should also never use a generator or other CO-emitting appliance inside your home. If you have an attached garage, avoid running a vehicle inside it, even if you have the garage door open.

The Carbon Monoxide Detector Tips and Advice

  • Before you buy a carbon monoxide detector, you’ll need to understand safe levels. These can vary from household to household, depending on the length of your exposure and the overall health of each person who lives there. Occupational Safety and Health Standards require workplaces to keep levels below 50 ppm, but many people won’t experience symptoms until at least 70 ppm. Heart patients may begin experiencing chest pains as levels rise within that range, though. Once carbon monoxide hits 70 ppm and keeps rising, occupants may notice an increase in headaches, fatigue and nausea. Levels between 150 and 200 ppm can cause unconsciousness and disorientation and eventually become fatal.
  • Accuracy should be a top priority when you’re comparing carbon monoxide detectors. One way to measure accuracy is to check a unit’s sensitivity. The Kidde Nighthawk Carbon Monoxide Detector can sense levels as low as 11 ppm but will only alert when the level gets dangerous. The First Alert Carbon Monoxide Alarm uses electrochemical sensors that can find both low and carbon monoxide levels.
  • Before you start shopping, determine exactly what type of danger detection you need. The Nest Protect Smoke & Carbon Monoxide Detector is a smoke and carbon monoxide detector in one. The unit combines both photoelectric and ionization sensors to monitor for fires. Those same sensors can also keep an eye out for signs of electrochemical carbon monoxide. Most other carbon monoxide detectors only handle CO detection, which means you’ll need separate smoke detectors. However, if you’re in the market for a new smoke detector as well, consider the First Alert Carbon Monoxide Alarm, which connects to other First Alert alarms to provide you with full-house protection.
  • With most CO detectors, you’ll only know once levels reach a certain threshold. However, both the Kidde Nighthawk Carbon Monoxide Alarm and the Alert Plus Carbon Monoxide Alarm show your current levels on an LCD display. The Alert Plus Carbon Monoxide Alarm Detector will begin issuing alerts within 60 to 90 minutes once you reach 50 ppm. If you hit 100 ppm, an alert will sound within 10 to 40 minutes, and 300 ppm sets off an alarm within three minutes.
  • If you do see an alert, it can help to know which part of your house the problem area is. The First Alert Carbon Monoxide Alarm lets you know where the threat is so that you can take action to fix it.
  • In addition to voice alerts to warn you of the danger, Nest Protect Smoke & Carbon Monoxide Detector has an LED that changes colors at varying levels. If you have low levels of smoke or carbon monoxide, you’ll get a yellow light while red light signals that you should exit the building immediately. The Alert Plus Carbon Monoxide Alarm also has a bright LED light.
  • When an alarm goes off, it’s important to have an alert at a volume audible to your entire household. The National Fire Protection Association recommends volume levels of at least 75 decibels. Both the Kidde Nighthawk Carbon Monoxide Alarm and First Alert Carbon Monoxide Alarm include alarms that are 85 decibels.
  • Another benefit of the Nest Protect Smoke & Carbon Monoxide Detector is that it connects to a smartphone app. This means you can log in and check your home’s levels even when you’re away.
  • One bonus feature on the Nest Protect Smoke & Carbon Monoxide Detector is that if you do need to exit, the alarm lights up the area to help you find your way out in the dark. It can also be linked up to the smart bulbs you have in your home to provide a visual alert when it’s time to evacuate.
  • You have two choices in how your carbon monoxide detector is powered. The Kidde Nighthawk Carbon Monoxide Alarm is a plug-in detector that runs off your home’s electricity. It also has a battery backup for those power outages. The First Alert Carbon Monoxide Alarm and Alert Plus Carbon Monoxide Alarm Detector are both battery-powered, so you’ll need to make sure you keep the batteries changed. The Nest Protect Smoke & Carbon Monoxide Detector is available in both wired and battery-powered versions.

About The Author

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Stephanie Faris 

Stephanie Faris is a novelist and professional writer. She lives in a beautiful one-acre home in the suburbs on the outskirts of Nashville. Her home and garden work has appeared on popular home sites. She's a true homebody and loves looking at new houses for sale for inspiration on her own home remodeling projects.