Carbon monoxide (CO) gas cannot be seen or smelled, but it does exist in your home. The only way to know the level of carbon monoxide inside your house is by using a detector. Though there are so many brands offering the detectors, only the best carbon monoxide detector will be able to give you the right data. So how do you find the best carbon monoxide detector?
To answer that question, we have created a list of CO detectors that could meet your needs. We tested 24 variants based on parameters like accuracy, connectivity, battery, etc. and also consulted 11 experts. After 142 hours of testing and evaluation, we created the list of CO detectors that work. To know about them, scroll down.
Best Carbon Monoxide Detectors
|Product Name||WiFi||Smart Device||Power||Price|
|Nest (S3003LWES)||Yes||Nest||Battery||Check Price|
|Kidde KN-Copp-3||No||No||AC||Check Price|
|First Alert CO400 Carbon Monoxide Detector||No||No||Battery||Check Price|
|Kidde 21008873 CO detector||No||No||Battery||Check Price|
|Onelink Safe & Sound||Yes||Alexa||AC||Check Price|
|Kidde KNCOB-DP2||No||No||AC||Check Price|
|Forensics CO Detector||No||No||Battery||Check Price|
1. Nest S3003LWES Protect – Best WiFi Carbon Monoxide Detector
- Smoke detector and carbon monoxide detector that speaks up in a friendly voice to give you an early warning when...
- 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 
Nest is a popular brand that offers home safety. The Nest S3003LWES Protect is an attractive package. Our team instantly fell in love with the design of the detector. It looks elegant and modern. It also comes with a light to indicate the level of the CO gas. It detects both smoke and carbon monoxide.
It does not have a display of its own, but all the data is shown on the phone via its app. So, even if you are away from your home, you can keep an eye on carbon monoxide gas.
As far as the installation is concerned, it is easy and comes with both wired as well as wireless variation. Choose the one that fits your need. During tests, both variants worked fine. However, with wireless, you might have to keep an eye on the battery level.
2. Kidde KN-Copp-3 – Best Home Carbon Monoxide Detector
- Digital display displays the level of carbon monoxide the unit is sensing
- Three convenient mounting options
- Peak level button displays the peak CO level recorded by the alarm since it was last reset
It is one of the most popular carbon monoxide detectors on the market. As a package, it is basic, but what works for the Kidde KN Copp-3 is its effectiveness.
The time it took to detect the change in the gas concentration is really fast compared to other top carbon monoxide detectors. The time it takes to detect any change in the gas concentration will always be the key. When the gas crossed the limit, it triggered the Alarm and kept alarming every five seconds until we pressed the reset button. We also noticed that if the gas concentration reduces in the room, the Alarm to dies down with it.
The installation is easy. You will require one detector in each room. The room we used for detection was 14 x 12 ft. and the detector was effective in every corner of the room. It doesn’t have any fancy features but has a LED display. The display only shows gas concentration.
3. First Alert CO400 – Best Budget-Friendly Carbon Monoxide Detector
- Keep your family safe with this easy to use, battery operated carbon monoxide alarm; Battery powered alarms provide...
- Features an advanced electrochemical carbon monoxide sensor that accurately detects carbon monoxide levels, no matter...
- A loud 85 decibel alarm sounds when CO levels reach dangerous levels
First Alert CO400 has a lot to offer at a very low price. This is what we like about the product. Though it doesn’t support any smart home devices, its simplicity and accuracy make up for it.
Being priced so low, you can install several detectors in your house. Thus, it allows you to cover most of your home without paying high prices. Besides, it gives you many battery options like a 10-year battery, alkaline battery, or AA battery. AC can also power it, but we suggest using cells as prime sources as you can place the detector in every corner of your house.
The installation of it was straightforward. With battery, we were practically able to install it wherever we liked. Even with AC power, we were able to install the detector in necessary places because of the long cord.
4. Kidde 21008873 Carbon Monoxide Detector – Carbon Monoxide Detector For Garage
- Digital Display - Displays the level of carbon monoxide the unit is sensing. Shows CO level in PPM (parts per million)....
- Battery Operated - Provides the best protection during power outages. Battery safeguard makes it difficult to close the...
- Test/Reset Button - Tests unit’s electronic circuitry & horn and resets the unit during alarm. Tests CO alarm circuit...
It is another great CO detector from Kidde. This variant of the detector is more compact and simpler. It operates on battery, which is what we were going for. When we were looking for a product that could perform well while running only on batteries.
But this is the case with most detectors, so you cannot outcast the detector for being a little slow to respond. It has two buttons test/reset and peak level. Peak level can be useful if you won’t see the highest concentration of gas it has measured even when the change in gas level is as low as 30 ppm.
As it is battery operated, you can install wherever you wish. The installation process is also very simple. We were able to install it even without looking at the manual.
5. Onelink Safe & Sound- Carbon Monoxide Detector For Alexa
- About safe and sound: First Alert introduces Onelink Safe and Sound, an Alexa enabled, Apple HomeKit compatible...
- Easy mobile controls: Get remote notifications of an emergency in your home for 24/7 safety, plus track carbon monoxide...
- No more confusing beeps: Track battery levels in the app and optimize safety by knowing when it’s time to replace...
It is by far the best smart carbon monoxide detector we have tested. What we loved about it is that it can be plugged directly into the socket. This reduces the work of installing it on a wall. It connects to Alexa via WiFi.
The other thing that works for it is that you require one Onelink Safe & Sound for 2-3 CO detectors. This is a great money-saving option. But we were curious to see how it would perform with the fact that you require only one or two for the house.
As for the connectivity via WiFi is concerned, it works fine with fast wifi networks. However, if you are phone is not connected to the same wifi network, you will not be able to receive the notification.
It also has small ambient light features that can be turned on during nights. You can change the color of the light, depending on the mood and interior.
6. Kidde KNCOB-DP2 – Best Plugin Carbon Monoxide Detector
- Tamper resist feature – Can be activated to cause unit to go into alarm if it has been unplugged or has come loose...
- 2 LED’s: Red - Illuminates when in alarm mode. Green – AC power is present, normal operation
- Test/reset button: Tests CO alarm circuit operation and allows you to immediately silence the alarm
It is the best plugin carbon monoxide detector we have tested. You can directly plug it into a standard wall outlet. Thus removing the process of installation. And during power outages, it can run on back up battery.
As far as the accuracy is concerned, it is right up there with top carbon monoxide detectors. Within a few minutes of change at the CO level, it was able to detect it. Upon crossing the dangerous level of CO gas, it triggers the Alarm. The Alarm is loud and clear.
The KNCOB-DP2 carbon monoxide detector placement is limited because of its plugin type, but it is best for places like a car garage, store, etc.
7. Forensics CO Detector – Best Carbon Monoxide Detector For Car
- 🚗 USES: Exhaust leaks in vehicles (i.e. SUVs, aircraft, school buses, trucks & fleet vehicles that triggers...
- 🔬ACCURATE: CO low-level alarm at 9ppm & 25ppm alarms WHO, EPA, ASHRAE, OSHA, NIOSH CO recommended exposure levels.
- 🔔 FAST ALARMS: Alarms at >9ppm @ 60 secs, compared to home CO detectors that only alarm >70ppm @ 60-240 minutes....
We wanted a CO detector that can be used for a car. Most of the detectors we tested were for a home. But CO is a prominent issue inside a car too. If you see the build, it small in size, which is required.
It comes with a LED display, showing the amount of CO concentration and battery. Thus, it gives the required information in one glance. However, unlike other CO detectors company offers only a year warranty on it, so make sure you change the detector after one year.
If you require a CO detector for your car or van, without any doubt, just go for the forensics.
Buyer’s Guide – What To Consider While Buying The Best Carbon Monoxide Detector?
When you are looking for the right CO detector, you have to know what your requirements are and the amount of money that you can spend. Once you know it, you need to keep in mind a few parameters like Alarm, accuracy, battery, display, and installation.
Let’s look at each factor one by one:
This is the most important factor to consider while buying the CO detector. The main reason being, if the detector fails to detect the rising CO level in your house, you and your family may be in danger. Ideally, the gas takes 30 minutes to affect the human body. Hence, the CO detector must be able to detect and notify you within 30 minutes. The carbon monoxide detectors can notify of the rising of gas within 3-4 minutes. The [Amazon link=”B00XV1RD0K” title=”Nest Protect (S3003LWES)” /] and Kidde KN-Copp-3 are quick to detect the rise in CO level.
Some of the CO detectors run on AC power supply, but even they use the cell as a back up in case of power outages. So to ensure that the detector continues to run, you have to keep an eye on the batteries. Almost all the CO detectors have an indicator or alert that informs you if the battery is running low. We do not recommend you buying only the hardwired wired detectors because most of the time, CO level rises only during the power outages. A detector that uses both AC and batteries as a power source is a good option.
The Alarm is an essential aspect of a CO detector. Firstly, the sound of the Alarm should be loud and clear enough to alert you the moment CO rises to dangerous levels. Some detectors may have beepers or voice alarms. Both work fine. The only thing to take care is that the alarm sound should be in good condition. The reason being if the sensor detects the CO level but does not trigger an alarm, then the detector is useless. With time speakers may get compromised, so it is vital to keep checking the detector every month or so. Many detectors have a test function, use the feature to test it.
4. Digital Display
The display is an essential factor if you want to keep an eye on the amount of CO level in the house. Besides, you also want to know about the battery. Therefore, many manufacturers either use LED display or connect to devices like the phone to display the data.
There are also some detectors that do not display either way. They may have some indicators to show the necessary data. Usually, these are not that reliable. We recommend only the detectors that either has an LED display or use your phone as a monitor. The Onelink Safe & Sound is the best CO detector if you want to see every do on your phone.
The amount of CO accumulated is different in every room. So you want a group of CO detectors that can cover the possible corner of the house or office. Hence, the spot where the detectors are installed becomes important.
You want to install detectors in such a way that they do not move much or should remain out of reach of kids or pets. For installation, the power source becomes crucial. If the detector uses only AC as a power source, you will have to limit yourself to areas near the power source. Battery operated detectors are more free and flexible enough to be installed anywhere.
So if you have a limited number of AC outlets, try to get battery-operated CO detectors for your house. And if you have no such limitations then, get the detectors with power cord.
6. Combo Options
Many manufacturers offer smoke detectors and CO detectors within one device. This way, you cover problems with one solution. As the manufacturer about it, if they have an option that covers both issues. In our list Onelink Safe & Sound covers both realms.
How We Conducted The Tests?
Currently, there are so many detectors available that it is impossible to understand each of them. Hence, we started by picking the most popular and trusted CO detectors. We designed a few tests for parameters like accuracy, battery, Alarm, installation, etc.
For tests, we used the top measurement tools to make sure the data we have is highly accurate. The biggest challenge for us was to measure carbon monoxide. We placed the detector in different areas of a model house to understand how the readings change. Thus, giving us a good idea about the sensitivity of the detector.
In addition to tests, we also wanted to learn more about the product. So we consulted 11 experts who have experience in home safety. Their views and expertise were valuable in knowing each product. Besides, we also reached out to the brand managers. This allowed us to understand the perspective of each brand. Lastly, we went through several review sites to know what the users think after using the particular model for several years.
By evaluating the results of your tests, expert views, brand manager’s perspective, and user reviews, our team scored each model. Based on the score, we categorized the different carbon detectors. Here is the scorecard of the top carbon monoxide detector:
|Nest (S3003LWES)||96.6||95.8||98.8||97.07||Check Price|
|Kidde KN-Copp-3||95.4||97.8||95.7||96.30||Check Price|
|First Alert CO400||95.8||96.4||95.4||95.87||Check Price|
|Kidde 21008873 CO detector||96.5||95.8||94.3||95.53||Check Price|
|Onelink Safe & Sound||94.8||95.8||94.3||94.97||Check Price|
|Kidde KNCOB-DP2||94.8||96.2||93.2||94.73||Check Price|
|FORENSICS CO Detector||96.2||93.8||93.4||94.4||Check Price|
1. Where to place the CO detector?
According to the Consumer Product Safety Commission, there should be at least one carbon monoxide detector outside every sleeping area. In addition to the bedroom, you may also want to add a detector in the kitchen and basement. Moreover, if you have a garage, you may want to install one at the entrance. The whole concept of install the detector is to keep the detectors close enough to hear the alarms as well as to detect the CO level more effectively. Another thing that identifies the installation of the detector is power supply. It is better to get a battery-powered detector so that you are not restricted to areas near the power outlets.
2. How to maintain CO detectors?
Most of the carbon monoxide detector last for five years. Even though the manufacture may promise a warranty of 7 years or ten years, the dust and moisture can make an impact on its lifetime. So you have to keep the detectors clean. Make sure that you clean the detectors as well as test them every month. Most of the models come with a test button. Upon pressing, it will check if the siren works or not. Besides, there are carbon monoxide test kits that can be used for the effectiveness of the detector. Every five years, make sure you replace the old detectors with a new one.
3. What to do if CO crosses the limit?
If the CO limit is reached and the Alarm is triggered, immediately leave the house and go outside into the fresh air. Check if any of your family members show CO poisoning. It would be a good idea to call 911 immediately for assistance. They will check for the poisoning.
The thing with CO poisoning is that symptoms are not visible immediately. It develops over a day or so. So consult a doctor. And do not go back to the house, unless until it is declared CO free.
When the safety of your house is concerned, you should never compromise on the type of detectors you use. Take as much time as possible to understand the product before you buy and install it in your home. And to help you make the right decision, we have given you all the information. All you have to do is find out what your requirements are and how much you are willing to spend on it.