10 Best Co Gas Detectors of 2022

A home fire safety plan is incomplete without a set of carbon monoxide detectors, which sense this odorless, poisonous gas and alert residents to its presence. Without a comprehensive system of carbon monoxide detectors, a family can be at serious risk. Overnight as occupants sleep, the gas can overwhelm them, leaving them with dull headaches, dizziness, and confusion.

Our testing was aimed at evaluating a few of the most popular models of these crucial devices, which come in a variety of different types. Here are the reasons why the units we tested were considered among the best CO gas detectors available, and how to choose a model.

Carbon Gas and How It’s Detected

The combustion process produces carbon monoxide (CO) as a byproduct: Any appliance that uses fuel (for example, a water heater, furnace, or boiler) produces carbon monoxide when in use. During normal operation, these appliances are extremely safe, but if something goes wrong, carbon monoxide can build up to dangerous levels. The excess carbon monoxide should be released outside through chimneys and vents.

A healthy adult can be killed by 1,600 parts per million (PPM) of carbon monoxide within an hour of being exposed to 50 PPM.

Since carbon monoxide is colorless and odorless, it is impossible for people to recognize its presence until it is too late, so carbon monoxide detectors are so important. In carbon monoxide detectors, levels of the gas are monitored over time and an alarm is triggered when the levels rise. Typically, a 50 PPM measurement will activate most alarms after 8 hours, 150 PPM within 50 minutes, and 400 PPM within 15 minutes.

During testing of the models reviewed here, a can of fake carbon monoxide was used. As most detectors require a prolonged presence of carbon monoxide to provide an alert, this method was not foolproof. Testing was possible, however, on some models due to test ports.

Detector Locations

Carbon monoxide detectors should be installed on every floor and in every bedroom. They should also be installed in the basement and garage.

Testing Intervals

The same precautions should be taken for carbon monoxide detectors as they are for smoke detectors. Carbon monoxide detectors require monthly testing, and batteries should be changed every year, regardless of whether the low-battery alarm sounds.

Device Lifespan

It doesn’t matter how regularly you change the batteries in a carbon monoxide detector, the detectors themselves don’t last forever. Check the back of the home’s devices to find out how long their expected lifespan is—usually between five and seven years. If homeowners cannot recall when they purchased the device, they should replace it right away.

Types of CO Gas Detectors

There are two types of carbon monoxide detectors on the market: stand-alone and combination. Choosing the right one for your home depends on several factors.


The only purpose of a standalone carbon gas detector is to detect and measure the levels of gas in the house. A battery-operated detector can be placed almost anywhere and is the most popular choice. For a permanent installation, choose a plug-in detector. Digital readouts often indicate the level of carbon monoxide being detected on these models.


Besides monitoring carbon monoxide levels, combination units can also detect smoke and explosive gases. Combination units simplify the process of building a fire safety system because they take out a lot of the guesswork and planning involved. For optimal use, combination carbon monoxide detectors should not be placed near gas or oil-fired appliances. The best method for detecting carbon monoxide in this situation is to install a separate carbon monoxide detector farther away from the smoke detector.

In contrast to popular belief, a carbon monoxide detector alone cannot detect explosive gases. Explosive gases do not contain carbon monoxide unless they are accompanied by burned fuel. When these gases are detected by carbon monoxide detectors with explosive gas detection capabilities, residents will be notified.

Our Top Picks

As a crucial component of home safety, carbon monoxide detectors are an important purchase. Here are some examples suited to various circumstances.

8 Best CO Gas Detector Reviews

1. Kidde Nighthawk Carbon Monoxide/Explosive Gas Alarm

Kidde Nighthawk Carbon Monoxide/Explosive Gas Alarm

A Kidde carbon monoxide detector can detect more than just dangerous levels of carbon monoxide; it can also detect explosive gases. With its digital display, you can monitor real-time carbon monoxide levels in the home, while the peak-level function shows you where you reached the highest level since you last reset it.

There is a battery backup on this model, and it plugs directly into an outlet or operates with the corded adapter included. Explosive gas detection is not immediate, and occupants are likely to smell gas before the detector goes off if they’re awake, but it’s an excellent safety feature for peace of mind when the household is asleep.

During our testing of the Kidde Nighthawk, we found it to be one of the only detectors that responded to our carbon monoxide test, alerting us to 157 part per million. We also liked the flexible mounting options, as the cable included makes it possible to install it anywhere within 7 feet of an outlet.

Although we weren’t thrilled with the size (it’s much bigger than the other plug-in models), we recognized that the digital display does need some extra space.

Product Specs

  • Type: Carbon monoxide/explosive gas
  • Power source: Plug-in or battery
  • Interconnectivity: None


  • The flexible plug-in allows use within 7 feet of an outlet
  • Detects both carbon monoxide and explosive gas
  • Digital reading displays the amount of gas in the air
  • Battery backup ensures unit function, even in power outages


  • Large, bulky design

Buy on Amazon

2. Kidde Battery-Operated Carbon Monoxide Detector

Kidde Battery-Operated Carbon Monoxide Detector

Those who are on a budget may want to look at Kidde’s battery-operated carbon monoxide detector, which is reliable against poisonous levels of carbon monoxide. This detector, which uses three AAA batteries, has a handy lockout feature on the battery door to prevent it from closing without batteries in place, ensuring the home is always safe.

It also features a low-battery signal, a built-in test button, and two LEDs, a green LED indicating proper operation, and a red LED indicating dangerous carbon monoxide levels.

Its simplicity is what made us love the Kidde Battery-Operated Carbon Monoxide Detector. Upon installation of batteries and mounting to the wall with two anchors and screws, this model was ready for use. Aside from its compact size and budget-friendly price, we also liked its features. However, it’s not very advanced, so shoppers who want smart features or interconnectivity will need to keep looking.

Product Specs

  • Type: Carbon monoxide only
  • Power source: Battery
  • Interconnectivity: None


  • Compact size
  • Low price makes having multiple units affordable
  • Very simple to set up and install


  • No additional features

Buy on Amazon

3. First Alert CO600 Plug-In Carbon Monoxide Detector

First Alert CO600 Plug-In Carbon Monoxide Detector

It is ideal for people who prefer a simple method of carbon monoxide detection such as the First Alert CO600. There is no need for batteries or hardwired connections with this device, and its compact design and prong placement won’t block both outlets in a double outlet.

As soon as carbon monoxide levels reach dangerous levels, this model features an 85-decibel alarm. As simple as carbon monoxide detection can get, it has just one button for testing and resetting, and no digital display or settings to mess with.

There aren’t a lot of features to discuss with the CO600. It’s just a bare-bones, affordable carbon monoxide detector that installs quickly and does its job. During our carbon monoxide test, it was loud enough to alert people from anywhere in the house, and it responded to the test. It should be noted, however, that the model does not have a backup battery, so it will shut down should the power go out.

Product Specs

  • Type: Carbon monoxide
  • Power source: Plug-in
  • Interconnectivity: None


  • Very simple design—literally just plug and play
  • Loud siren
  • Did respond to CO test, thanks to test port on the front of the unit


  • Shuts off when power goes out

Buy on Amazon

4. Kidde Firex AC Hardwired Carbon Monoxide/Smoke Alarm

Kidde Firex AC Hardwired Carbon Monoxide/Smoke Alarm

The Firex model from Kidde has some great features, despite being a hardwired smoke detector. To make sure users understand the hazard involved, hardwired smoke and carbon monoxide detectors shout voice alerts when they detect smoke or carbon monoxide.

Additionally, this Kidde model can be connected to an existing fire alarm system with the included wiring plug or run on a 9-volt battery. Due to its hardwired nature, it is able to communicate with up to 24 devices, including smoke detectors, carbon monoxide detectors, and heat detectors.

While the Kidde Firex combination smoke detector is a hardwired model, we appreciated the versatility of power sources between wired power or batteries. Voice alerts were very loud, intense, and clear. There is a small release mechanism on the base that we had to locate, but beyond that, using this smoke detector was extremely easy, down to its battery on the front.

Product Specs

  • Type: Smoke/carbon monoxide
  • Power source: Hardwired or battery
  • Interconnectivity: Yes, with up to 24 other devices when hardwired


  • Hardwired plug makes installing it into an existing system easy
  • Battery backup ensures it can operate even if the power is out
  • Very loud, clear, and intense voice alerts


  • The base was slightly finicky to operate

Buy on Amazon

5. First Alert SCO5CN Smoke/Carbon Monoxide Detector

First Alert SCO5CN Smoke/Carbon Monoxide Detector

The First Alert combination model is exactly what some people are looking for: a reliable, easy-to-use detector they can install and check multiple times a year, rather than the latest smart technology. Both the smoke and carbon monoxide sensors are tried-and-true, reliable, and feature photoelectric sensors for smoke detection.

This combination smoke and carbon monoxide detector is battery-powered, so it can be easily installed anywhere. In addition to its loud 85-decibel alarm, it also comes with lockable pins in the base that can be installed to ensure the battery drawer stays closed, keeping the batteries in place. We were able to test this model for carbon monoxide (it has an attachment for the straw).

However, we found the First Alert battery drawer confusing and frustrating. Instead of swinging outward from the unit, it pulls straight out, as if it were a dresser drawer. We hope users will be able to get used to it, as we also found the First Alert very effective and easy to install.

Product Specs

  • Type: Smoke/carbon monoxide
  • Power source: Battery
  • Interconnectivity: None


  • Features 2 reliable detection sensors for user peace of mind
  • Base has locking pin to prevent battery disconnection
  • Easy to install; requires no wiring or power source


  • Confusing battery drawer

Buy on Amazon

6. Google Nest Protect Smoke and Carbon Monoxide Alarm

Google Nest Protect Smoke and Carbon Monoxide Alarm

Detects smoke and carbon monoxide and can alert households even if members are not present. Google’s Nest Protect is a worthy smart home alarm.

In the event that Nest activates, it notifies the homeowner’s app, smart-home system, and central monitoring company via their Wi-Fi network. Because Nest is interconnected, it will also alert other smart alarm devices. During the middle of the night, groggy residents can benefit greatly from voice alerts about hazard conditions and the room where hazards are detected.

The Google Nest Protect was one of our favorite models in the test. It provides clear voice alerts that are easy to understand and also has a cool yet unobtrusive appearance (it looks like a speaker). With the QR code included on the back of the detector, setting up the app was easy (though it was an additional step other models tested did not require).

For a square, clean installation, users can easily align their Nest Protect with the home’s walls because the base is able to swivel. Although we have added this model to Nest easily, we haven’t been able to do so on Google Home.

Product Specs

  • Type: Smoke/carbon monoxide
  • Power source: Rechargeable battery
  • Interconnectivity: Yes, with other Nest devices


  • Clear, specific alerts to hazard condition and room where detected
  • Physical installation and setup with the app are both very simple
  • Good-looking design
  • Swiveling base allows for perfect alignment in installation


  • Wouldn’t link with our Google Home app

Buy on Amazon

7. X-Sense CO03D Carbon Monoxide Alarm

X-Sense CO03D Carbon Monoxide Alarm

It may make the most sense to purchase a set of detectors when you want enough coverage for your entire home. The three-pack combines smoke detectors and carbon monoxide detectors, making it ideal for covering most of your fire safety needs. These detectors feature a 10-year battery and are capable of sensing both smoke and carbon monoxide.

This unit measures carbon monoxide and displays the PPM on its easy-to-read LCD display. Green indicates proper function, yellow indicates faults, and red indicates an alarm.

We have some experience with X-Sense products, and in the past, we weren’t a fan. However, it appears that the company addressed some of the issues we previously had to create a high-quality, streamline carbon monoxide detector. In spite of not sounding an alarm, the digital display is very easy to understand, providing real-time readings to alert the user to the conditions within the home.

It worked very well and established our faith in X-Sense. We would have preferred a recall button that displayed the highest detected levels since last reset, but otherwise, the model worked well.

Product Specs

  • Type: Carbon monoxide
  • Power source: Battery
  • Interconnectivity: None


  • Slim, compact design yet with an easily understood digital display
  • Real-time readings for carbon monoxide levels within the air
  • Users needn’t check digital display to know overall condition


  • No recall button

Buy on Amazon

8. First Alert SC7010BV-3 Talking Smoke/CO Alarm 3 Pack

First Alert SC7010BV-3 Talking Smoke/CO Alarm 3 Pack

You might want to consider a multipack like First Alert’s SC7010BV-3 Talking Smoke/CO Alarm when your old smoke detectors are nearing the end of their life (typically 10 years). Users can use this pack of three detectors to replace their aging hardwired or battery-powered smoke and carbon monoxide detectors. It has 11 preprogrammed locations to alert users to exactly where the danger is coming from.

Its voice alerts communicate clearly the hazard at hand to disoriented residents, helping them understand what’s happening better than standard beeps.

We found it very easy to program the location of these units in testing, which was surprising since there is only one button to use. We liked that these models came with easy-to-wire plugs and bases that proved easy to install, even though the speaker did sound a bit muffled, so voice locations might not seem as clear as some people might need. They do have an accompanying alarm, however.

Product Specs

  • Type: Smoke/carbon monoxide
  • Power source: Battery or hardwired
  • Interconnectivity: Yes, when hardwired


  • Voice alerts to state precise hazard and location
  • Multipack
  • Choice of 11 locations
  • Programming devices to the location is very easy


  • Speaker sounded slightly muffled

Buy on Amazon

What to Consider When Choosing the Best CO Gas Detectors

Battery-Powered, Plug-In, or Hardwired?

A few different power-supply options are available with carbon gas detectors:

  • Battery-powered This convenience makes it a good idea to use a battery-powered unit in a garage workshop that uses propane heat. The models do not require electrical outlets or pre-existing wiring and can be placed virtually anywhere in the house.
  • Plug-in It is important to note that plug-in models require an outlet. This greatly restricts the options of installation, though these units have battery backups should the power go out. Plug-in models are useful for adding additional protection to areas with smoke detectors.
  • Hardwired units are often the most desirable, and should be used whenever possible, but not all homes have fire alarm wiring that runs throughout the house. They use pre-existing wiring for the fire alarm and battery backup for their power source.

The comprehensive system may include units from all three categories, depending on the situation.

UL Listing

A carbon gas detector must be listed by Underwriters Laboratories (UL), just like a smoke detector. In light of the importance of carbon monoxide detection, only UL-listed models should be purchased. A UL listing indicates that the design was tested and passed UL’s strict requirements.

Digital Displays

Despite their appearance, digital displays serve a fairly important purpose. These units will display the PPM of any level of carbon monoxide they detect, even if the alarm mode is not activated. By doing so, residents can determine if their home has more baseline carbon monoxide than they thought; a standard carbon monoxide detector cannot do this.


It is considered an interconnect-capable carbon monoxide detector when it can be programmed or wired with other alarm devices in the home through radio frequency, Wi-Fi, or direct wiring.

If you are comfortable linking household systems together, interconnect-capable units can be a great benefit for those comfortable with connected homes. The occupants of the house will be notified regardless of where they are in the house if the garage is notified of carbon monoxide.

As soon as the device reports back to the central monitoring station, first responders will be notified and help will be sent to the resident without them even picking up the phone. Especially at night, when sleepers might not hear the garage alarm blaring and when symptoms of carbon monoxide poisoning are less likely to show, this can be a huge benefit.

Smart Features

With smart appliances and fixtures, such as refrigerators and faucets, detection devices have joined the ranks. They are often smoke and carbon monoxide detectors combined. Smartphone apps, base stations, or smart-home systems can communicate with these devices. As well as providing real-time condition updates to an app, they can be programmed to describe the area and type of device activated.


Despite reading up on carbon monoxide detectors and how to pick one, you may still want to learn more about how these essential devices work. Take a look at some of the most commonly asked questions about carbon monoxide detectors to learn how they work.

Q. Where is it best to place a carbon monoxide detector?

It is best to place the detector 5 feet above the floor, as carbon monoxide is lighter than air and will travel with warm, rising air. Also, place the detector outside of sleeping areas, if not within the bedrooms themselves. Install at least one carbon monoxide detector on each floor and inside a garage. Follow the manufacturer’s placement and usage instructions.

Q. How many carbon monoxide detectors do I need for my home?

It is recommended by the Centers for Disease Control and Prevention to install at least one carbon monoxide detector per floor. However, the more the better.

Q. Is it better to have a battery or plug-in carbon monoxide detector?

The battery-operated, plug-in, and hardwired detectors have different benefits, and none are more effective than the other. You might find the best coverage is achieved when you combine them.

Final Verdict

A simple installation process and digital readout make the Kidde Nighthawk carbon monoxide detector a great choice for those looking for a carbon monoxide detector. Google Nest’s carbon monoxide detector, however, is a bit more high-tech and can connect to a smartphone or report to it.

Leave a Comment