best low level carbon monoxide detector

8 Best Low Level Carbon Monoxide Detectors For Your Home

Carbon monoxide (CO) is a silent killer. It’s an odorless and colorless gas that can put your family’s life at risk. This is why you should have an early warning system in the form of the best low level carbon monoxide detector. This device will set off once it detects elevated levels of CO in the air. It will also give you peace of mind that your indoor air is safe to breathe.

Below, I reviewed eight of the most reliable carbon monoxide detectors you can use in your home. See which one matches your budget and the features you’re looking for.

 Our Top Pick! 
Google Nest Protect
Carbon Monoxide Detector
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Kidde Nighthawk
Carbon Monoxide Detector
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Carbon Monoxide Detector
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Carbon Monoxide Detector
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Kidde ‎21006407
Carbon Monoxide Detector
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X-Sense CO03D
Carbon Monoxide Detector
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Onelink Smoke &
Carbon Monoxide Detector
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Carbon Monoxide Detector
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What is carbon monoxide?

Carbon monoxide (CO) is a colorless and odorless gas produced by the incomplete combustion of fuel. It’s a flammable gas and slightly denser than air. Such characteristics make CO impossible to detect by smelling or feeling the air.

Take note that carbon monoxide is so deadly that a concentration of 70 parts per million (ppm) is enough to induce adverse reactions. On higher concentrations, an exposed individual will suffer from brain damage, organ damage, and death. You’ll feel dizzy, nauseous, and weak.

The worst part is that you’ll be unconscious before the life-threatening effects took place, which deprives you of the chance to seek fresh air. CO works by interfering with your blood’s ability to carry and transport oxygen all over the body.

Another daunting fact is that carbon monoxide can be easily present in your home. The following are some of the potential sources of CO in a household setting:

  • Clothes dryers
  • Furnaces
  • Fireplaces
  • Water heaters
  • Wood stoves
  • Gas stoves
  • Tobacco smoke
  • Generators

There are other potential sources of carbon monoxide in and out of your house if it’s burning fuel, whether gas or wood, it can potentially create dangerous CO.

Don’t get this wrong. You can still use fuel-burning appliances as long as you do so in a ventilated area. For example, you should only run a portable generator at least 20 feet away from your house.

Maintenance is also crucial to prevent carbon monoxide poisoning. A good example here is your clothes dryer. It’s usually harmless since it uses electricity. However, the appliance may burn the accumulated lint, resulting in carbon monoxide production.

How does a carbon monoxide detector works?

Due to the risk, carbon monoxide exposure entails, experts have developed a device that will detect increased levels of CO in the air.

A carbon monoxide detector is made similar to an alarm clock. But instead of counting down the time, it sets off when the detector picks up a certain amount of carbon monoxide within a timeframe.

This detector is made to alert you even before you start feeling the symptoms of carbon monoxide exposure. It gives you the chance to run outside and open the windows for ventilation.

Take note that you have to move fast once the detector sets off. Even at low doses, CO can be deadly. The last thing you want is passing out inside your house as the carbon monoxide levels climb.

Also, you’re not supposed to re-enter the room until the alarm has turned off. This is why ventilation is necessary.

Best Low Level Carbon Monoxide Detector – Top 8 Picks!


OUR TOP PICK: Google Nest Protect Smoke & Carbon Monoxide Detector
best low level carbon monoxide detector

Product Name: Google Nest Protect Smoke & Carbon Monoxide Detector

Product Description: When it comes to the best low level carbon monoxide detector, my money is on Google Nest Protect. This smoke and CO detector will give you an early warning even before the gasses become dangerous for your health. Moreover, this uses a Split Spectrum Sensor that detects smoldering and burning fires nearby. It will send a warning to the mobile app and tell you where the excessive levels of CO are located in your house. You can also silence the smoke alarm through the app in case there’s only a little smoke. This detector also has a human voice feature that will announce the warning to you. It prevents people from panicking and getting startled by high-pitched alarms.

Offer price: $$$

Availability: InStock

  • Accuracy
  • Reliability
  • Ease of Use
  • Value for Money


Another thing I like about the Google Nest Protect CO detector is its Pathlight. When you walk underneath the device, the Pathlight will turn on to illuminate your way. It saves you from the hassle of turning the lights on and off.

I also like that the device tells you that it’s running out of power. The light will also indicate once it’s time to replace the power source.

Also, this smoke and carbon monoxide detector have a 10-year lifespan. While the upfront cost is higher, it’s worth the splurge for a whole decade of protection for your family.

Overall, this is an accurate and well-made CO detector. You can also get this in battery or wired versions based on your liking.


Friendly voice feature that warns of CO levels

Mobile app notifs

10-year lifespan


Challenging to install


Kidde Nighthawk Carbon Monoxide Detector

best low level carbon monoxide detector

If you’re looking for a wall-mounted CO detector, you should consider the Kidde Nighthawk Carbon Monoxide Alarm. This uses an electrochemical sensor that will detect carbon monoxide and other flammable gasses in the air. It includes propane gas and natural gas leaks.

Aside from that, this device uses an 85 dB alarm enough to wake you up in the middle of the night without being deafening. It’s also easy to install and works as a combination of gas and smoke alarms for the price of one.

This is a UL-certified carbon monoxide detector with a 5-year limited warranty. I also like the digital display that projects the ppm of carbon monoxide in real-time. This allows you to see if your indoor air is getting more polluted.

Moreover, this has a Peak Level Memory that can recall the highest carbon monoxide concentration that has been detected.

Take note that this is a plugin device, which means you need a wall socket to power this up. It also has a battery backup in case a power outage occurs. This doesn’t have interconnects, which is not a big deal.

Overall, this has a 7-year lifespan, but always check the packaging date as this is where the countdown really begins. It’s an excellent choice for boiler rooms and kitchens if you want a smaller device to mount.

  • A loud alarm that can wake you
  • Detects all flammable gasses
  • Works in both battery backup and plugin options
  • Shorter lifespan than other CO detectors

FIRST ALERT Plug-In CO600 Carbon Monoxide Detector

best low level carbon monoxide detector

The FIRST ALERT Plug-In CO600 is a three-pack carbon monoxide detector. This way, you can cover multiple rooms for a small price.

These units use electrochemical sensors that will accurately detect CO levels in your home. It also has test & silence buttons for easy control. And once the detector is nearing the end of its lifespan, there’s also an end-of-life warning to let you get a replacement on time.

Moreover, these CO detectors have 85 dB alarm sounds that will notify you once dangerous levels of carbon monoxide have been detected.

All these three units have passed the UL standards. It also has a plugin design, so there’s no need to drill holes. You only have to plug it on an elevated wall socket, and it’s good to go. There’s also a low-battery indicator once the backup is in need of a replacement.

Overall, these three units are offered at a reasonable price point. It’s an excellent alternative if you don’t have the money to splurge for a Google Nest unit.

While this CO detector is nothing fancy in terms of design and appearance, it gets the job done. For someone on a budget, it’s all that matters.

  • Plugin design, no special installation needed
  • End-of-life warning
  • UL-listed
  • Not the fanciest carbon monoxide detector, but it works nonetheless.

FIRST ALERT CO615 Carbon Monoxide Detector

best low level carbon monoxide detector

Another FIRST ALERT unit I recommend is the CO615. This carbon monoxide detector has a digital display that lets you see CO levels in your home in real-time.

Moreover, this unit uses an electrochemical sensor that will accurately detect the presence of carbon monoxide. It also has an 85 dB alarm that will warn everyone in the house once CO levels go higher than safe levels.

Aside from that, the FIRST ALERT CO615 has a backup battery and an easy plugin design. There’s no need to use special tools to get this working. In addition, its plug-and-play design makes it a convenient choice for mobility-challenged individuals.

This CO detector has a 7-year limited warranty with an end-of-life signal chirp to let you know once replacements are needed.

Overall, this is a UL-listed carbon monoxide detector that you can get at a low price. It’s a low-cost solution for building compliance without compromising the accuracy of its performance.

The only thing I wish they will improve is the user manual. The font is so tiny that even a person with 20/20 vision can’t read it. Other than that, it’s a functional carbon monoxide detector without too many frills.

  • 7-year limited warranty
  • Equipped with a backup battery
  • Plug-and-play design
  • The user manual is so tiny you can’t even read it.

Kidde ‎21006407 Smoke & Carbon Monoxide Detector

best low level carbon monoxide detector

If you’re looking for a more permanent solution, you should get the hardwired Kidde 21006407 Smoke & Carbon Monoxide Detector. This is a fire and CO alarm that uses an alert mode with a voice prompt.

It will state “Fire! Fire!” or “Warning! Carbon Monoxide!” once it detects harmful levels of the toxic gas. There’s also a “Low Battery” announcement to let you know if the backup power source is in need of a replacement.

Aside from that, this has a Test-Hush feature that allows you to silence the unit for up to 8 minutes. It’s also tamper-resistant that prevents the removal of the detector from where you installed it.

Moreover, this uses a photoelectric sensor technology that will detect fire particles in real-time. It uses an 85 dB alarm sound, which is pretty standard on CO detector units.

This has a backup battery as well Quick Connect design with snap-on electrical harnesses. This way, you don’t have to fiddle with manual wiring work just to get this working. I also like the digital display that will show you the CO levels in real-time.

Overall, you can interconnect 25 of these Kidde carbon monoxide detectors all over your home. It’s easy to install and offered at a reasonable price.

  • It uses a voice recording + beep alarm
  • Test-Hush feature
  • Front-loading backup battery
  • The interconnect feature is only one way.

X-Sense CO03D Carbon Monoxide Detector

Another three-set CO detector I recommend is the X-Sense C003D. Each of the carbon monoxide detectors in this pack uses a Figaro electrochemical sensor that will instantly detect the presence of carbon monoxide.

Aside from that, this detector has a digital display that shows the real-time CO levels in your home every 10 seconds. It also has LED indicators for the alarm, power, and fault.

The alarm of the X-Sense CO03D will set off when it detects 70 ppm within 60 to 240 minutes. It will also alarm faster at 150 ppm within 10 to 50 minutes and 400 pm in just 4 to 15 minutes. This is the best low level carbon monoxide detector if you’re on a budget.

Just note that this is a battery-powered unit that uses three AA batteries. Its sensor has a 10-year lifespan equipped with an end-of-life warning to warn you once it requires a replacement.

Aside from a carbon monoxide detector, you’ll also receive screws and anchor plugs for quick installation.

The best thing is that the X-Sense CO03D is covered by a 60-day money-back guarantee. They also have an after-sales service to help resolve issues with the units.

Just know that the batteries of these CO detectors only last for 3 to 5 years and need to be replaced after that. If you want a long-lasting option, you can upgrade to the CD07 or SD06 models from X-Sense.

  • 60-day money-back guarantee
  • 10-year sensor lifespan
  • Equipped with a digital display
  • Shorter battery life, but not really a deal-breaker

Onelink Smoke & Carbon Monoxide Detector

The Onelink Smoke & Carbon Monoxide Detector has a smart function that detects both smoke and CO. It has a photoelectric smoke sensor as well as an electrochemical monoxide sensor. This combo will ensure accurate and on-time readings every single time.

Moreover, this unit has voice alerts that will announce the type of danger and where it’s located. It will also send mobile notifications to the app, so you’ll know if there’s a threat even if you’re not at home.

This CO detector is also Alexa-compatible that allows users to interconnect multiple units at a time. With interconnected detectors, it only takes one unit to trigger all the connected devices. This is very helpful if you have a large house and you can’t hear individual alarms per room.

Aside from that, this Onelink CO detector has 5-year battery life. In addition, the battery is replaceable to get the most out of the detector.

I also like that the mobile notif has a direct button to dial 911 once it detects a fire or high levels of carbon monoxide. It’s an intuitive and helpful tool, especially for the elderly who have problems dialing on the phone.

The only thing I noticed is that setting up the interconnected units isn’t the easiest. It takes a lot of trial and error to finally connect everything. It’s something Onelink can improve on their next releases.

  • Uses two sensors
  • Programmed with voice alerts
  • Allows interconnection of multiple units
  • Not easy to install

FORENSICS DETECTORS Portable Carbon Monoxide Detector

My last pick for this roundup is the FORENSICS DETECTORS Portable Carbon Monoxide Detector. Unlike the previous units I reviewed, this one can be carried in your pocket. This will let you monitor the indoor air wherever you are in the house. It’s also handy outdoors or when driving a car and riding a plane.

This portable CO detector will set off at 9 ppm in 60 seconds. It’s an excellent choice for those who have respiratory problems and sensitivities to low levels of carbon monoxide.

Moreover, the FORENSICS DETECTORS Portable Carbon Monoxide Detector uses buzzer alarms, and bright red LED lights. There’s also a small digital display that you can easily see even in the dark.

Aside from that, this unit can work for up to 12 months before requiring battery replacements. It also uses a one-button operation and a 3M stick-on mount if you want to put it on the wall.

This uses a high-quality Japanese sensor that has been factory-calibrated for accuracy. It’s a lifesaver, especially if your home is prone to having high levels of carbon monoxide.

Overall, this compact CO detector is sensitive and reliable. It’s also a low-key device that offers advantages for a low price.

However, you can’t use this for building code compliance. You still need to use standard, UL-listed units. 

  • Japanese CO sensor
  • Will trigger at 9 ppm within 60 seconds
  • Compact and portable
  • Not for building code compliance purposes

How to choose a carbon monoxide detector

There are many carbon monoxide detectors in the market, so choosing one can be a challenging task. It’s important to check for the following aspect to get the best value:

Sensor type

  • The first thing you should check is the sensor type the carbon monoxide detector is using. The most common options in the market are biometric, metal oxide semiconductor, and electrochemical sensors.
  • Biometric. This carbon monoxide detector uses a special gel that changes in color when exposed to carbon monoxide. Once it changes color, the alarm will set off.
  • Metal oxide semiconductor. This sensor uses a silica chip circuity instead of a gel. When the chip is exposed to carbon monoxide, its electrical resistance will decrease. This will trigger the alarm.
  • Electrochemical. With an electrochemical sensor, the detector has electrodes that will sense the changes in electrical currents as it gets exposed to CO. When a chemical change occurs, it will set off the alarm.


Next, you should consider the sensitivity of the carbon monoxide detector. This is measured based on the lowest carbon monoxide concentration required to set off the alarm.

It’s measured by parts per million or ppm. The Underwriters’ Laboratories (UL), a leader in third-party certification, requires carbon monoxide detectors to set off within 90 minutes when exposed to 100 ppm of CO. It should be within 35 minutes on 200 ppm and 15 minutes on 400 ppm.

If you have a very low tolerance to CO, you should invest in the best low level carbon monoxide detector. This will set off the alarm once it gets exposed to gasses below 100 ppm.

Digital display

I always recommend getting a CO detector with a digital display. This projects the carbon monoxide levels in real-time, which allows you to perform ventilation once the numbers are going up. Such a feature makes it easier for homeowners to monitor their indoor air quality.

Still, this part isn’t a requirement. Other users get annoyed with the lighting of the digital display and the fact that it consumes more battery power.

Power source

One of the most important things to consider is the power source of the carbon monoxide detector. It can be battery-powered, plugged-in, or both.

With battery-powered CO detectors, installation is a breeze. There’s no need to work on wires and power connections. However, you’ll have to purchase battery replacements periodically.

On the other hand, there are plugged-in units that require electrical work. It’s permanently connected to the power source, so there’s no need to buy batteries. The only downside here is the extra work needed and more complicated maintenance.

Lastly, there are units that are equipped with both battery slots and plugged-in functions. When a power outage occurs, the backup battery will kick in. It ensures that the device will keep detecting carbon monoxide come what may.

Reset and controls 

Opt for carbon monoxide detectors with easy controls that will let you reset the device easily. If possible, look for a unit that will not reset its settings even if a power outage occurs. This will save you from the hassle of tweaking the device every single time.

Additional detection

Aside from CO, carbon monoxide detectors are often built to serve as a fire alarm by detecting smoke. This is an excellent feature since you’ll be monitoring two harmful elements in one device. In addition, it will save you from buying separate smoke detectors for your home.

Value for money

Lastly, always consider the value for money of the carbon monoxide detector you’re going to buy. This is why I don’t recommend extremely cheap units. While you’ll save a lot of money upfront, the long-term performance is likely below standard.

Always invest your money in CO detectors that have been UL-listed and certified by other third-party laboratories. This is proof of the device’s accuracy.

Things to do when the carbon monoxide detector goes off

If your CO detector set off, you should know what to do to avoid poisoning. Here are some of the things to keep in mind:

  • Don’t panic! When the CO detector alarm goes off, it’s easy to panic. But instead of losing control, you should open as many windows and doors as you can. Your goal at this point is to increase ventilation to allow the carbon monoxide concentration to dissipate. The trick is to open the windows and doors you’ll pass along as you exit your home—no need to spend too much time indoors trying to crack every window.
  • Don’t re-enter your home. As long as your CO detector is sounding, you should never enter your home. The sound indicates that there are still high levels of carbon monoxide inside, which will harm you.
  • Call 911. You can call 911 to ask for emergency responders if you’re experiencing symptoms. They can forward you to the right experts that will help get rid of the CO concentration. Firefighters are also trained to handle carbon monoxide situations. 
  • Get fresh air. The moment your detectors set off, head to the nearest exit while opening doors and windows along the way. Once you’re sure that you’re away from the source of CO, take deep breaths to consume as much oxygen as possible.

Tips to avoid carbon monoxide poisoning

Since CO is odorless and colorless, many people get exposed to it without knowing it. To prevent the risk of poisoning, you should make the following a habit:

  • Open the garage before turning the car on. Emissions from your car is a major source of carbon monoxide. Make sure that you open the garage first before you start the vehicle to prevent the accumulation of gasses.
  • Maintain your furnaces regularly. For your family’s safety, you should get your fireplace and chimney serviced each year. This includes cleaning and repair to ensure that the smoke is exiting your home.
  • Ventilate appliances properly. Always practice proper ventilation when using stovetops, space heaters, furnaces, portable generators, and grills.
  • Never run an engine in an enclosed space. Whether it’s a car, a water pump, pressure washer, and so on, never leave it running in an enclosed space. Doing so will allow the by-products of gasoline to accumulate, including the dreaded carbon monoxide.

Frequently Asked Questions

Q: Where should I place my carbon monoxide detector?

A: You should install or place the carbon monoxide detector on a wall or ceiling that’s at least five above the floor. Also, you should avoid placing it over stoves, ovens, and other heat-producing appliances. This will prevent false readings and unintended alarms. It’s also smart to put one detector per room and multiple units all over the house.

Q: Do cheap carbon monoxide detectors work?

A: A cheap CO detector can work, but there’s no guarantee of its accuracy. It’s best to invest in a CO detector that’s been UL-listed, lab-tested and proven by thousands of homeowners. Besides, it’s an investment for your family’s safety.

Q: Can low levels of carbon monoxide make you sick?

A: Low levels of carbon monoxide can give you flu-like symptoms, including nausea, headache, and shortness of breath. However, prolonged exposure to low levels of CO can lead to more serious conditions, especially to those suffering from other ailments.

Q: Will opening a window help with carbon monoxide?

A: Opening a window is the most convenient way to aerate the carbon monoxide inside your home. It will also maintain good airflow, though it could be at the expense of clean air. Sometimes, indoor air is polluted with dust, pollens, and molds. Still, it’s way safer than having to inhale CO at home.

Q: How long does it take to remove carbon monoxide from your system?

A: For those who had inhaled CO, it will take up to five hours to reach the half-life of the gas. This can speed up through oxygen supplementation. If you’re feeling the symptoms of carbon monoxide poisoning, you should seek medical help right away. You shouldn’t wait for life-threatening effects before you ask for help.

Q: Is it illegal not to have a carbon monoxide detector at home?

A: Each state has specific laws requiring the installation of carbon monoxide detectors in all private dwellings.  So far, there are a total of 27 U.S. states with such laws in place. Some of them are Colorado, Maryland, Alaska, Iowa, Michigan, California, Connecticut, and more.

Final words

When it comes to your family’s safety, you simply can’t put your guard down. It’s important to exhaust all means to curb indoor air pollution as well as deadly gasses like carbon monoxide.

The best low level carbon monoxide detector can be a lifesaver. Since you can’t smell or see CO, a detector in place will be your warning system. Just make sure that you’re investing in an accurate, reliable, and compliant unit. This will guarantee long-term performance and protection for your home.

What do you think of these CO detectors? Share your thoughts below in the comment section!