Combination smoke alarm/CO detector. Tests air at least 400 times per day. Unit typically lasts for 10 years (longer than average).
Expensive. CO readings not given in ppm.
Lightweight and portable. Gives extremely sensitive ppm readings.
Pricey. Not designed for home use (although home use is possible).
Portable and affordable. May be plugged into a wall socket or operated via battery.
Some questions about accuracy of the manual vs. what is found online.
Stands out for sealed lithium battery that's rated to last 10 years. Company backs the claim with 10-year warranty. Alarm is loud. Bracket included.
Some battery malfunctions, but the warranty provides peace of mind.
We purchase every product we review with our own funds — we never accept anything from product manufacturers.
We purchase every product we review with our own funds — we never accept anything from product manufacturers.
There’s a good reason why carbon monoxide (CO) is known as “the silent killer.”
This odorless, colorless gas is found in the fumes of cars, trucks, fireplaces, grills, gas stoves, furnaces, lanterns, and other small engines, and it is absolutely deadly if it builds up to a high enough concentration.
In fact, more than 400 Americans die from carbon monoxide poisoning each year, while 20,000 people go the ER with symptoms and 4,000 people are hospitalized.
Those statistics are definitely scary, but there’s one simple way to protect your family from carbon monoxide poisoning: a carbon monoxide detector. Installing a carbon monoxide detector can alert you to dangerous levels of the gas in your home so you can evacuate as soon as possible.
All carbon monoxide detectors are not created equally, though, so it’s important to know what features to look for to ensure you’re choosing the best model to protect your family.
After studying the top carbon monoxide detectors on the market and speaking with our expert consultant Allen, we’re eager to pass along the information we’ve gathered to help you make an informed shopping decision.
If you’re ready to buy a carbon monoxide detector, take a look at the product list above for our recommendations.
For general information on what to look for in a carbon monoxide detector, continue reading our shopping guide.
Carbon monoxide poisoning can affect anyone, but infants and the elderly are particularly vulnerable.
Individuals with chronic conditions such as heart disease, anemia, and breathing issues are also at greater risk for carbon monoxide poisoning.
To ensure that everyone in your home is safe, a carbon monoxide detector is a necessity.
Allen Rathey is a cleaning expert who promotes healthier indoor spaces. He is past-president of the Housekeeping Channel and the Healthy House Institute, and principal of the Healthy Facilities Institute (HFI) culminating more than 30 years of experience in making indoor places cleaner. He has been tapped as an expert by the New York Times, Real Simple, U.S. News & World Report, and other national media.
The symptoms of carbon monoxide poisoning are often similar to those of the flu.
You may experience dizziness, weakness, headache, upset stomach, vomiting, and chest pain. Confusion and/or disorientation are also common. And if you inhale a large amount of carbon monoxide, you could pass out or die.
If individuals are asleep or drunk when exposed to carbon monoxide, they may die without ever showing any symptoms.
Although the CO-monitoring aspect of the Nest Protect 2nd Gen Smoke + Carbon Monoxide Alarm appears to take a backseat to its smoke-detecting feature, users get the same level of protection against toxic carbon monoxide buildup as they do from fire. Most home CO detectors are designed to sample the air and record carbon monoxide levels over time. Long-term exposure to low levels of CO (in the 30 PPM or lower range) can be just as hazardous as short-term exposure to high levels of CO (450 PPM or more). The Nest Protect measures both long-term and short-term exposure.
If you’re suffering from flu-like symptoms – dizziness, headache, upset stomach, vomiting – check your carbon monoxide detectors. Are they working? Are your levels up? These flu-like symptoms are sometimes a sign of elevated CO in the home.
A carbon monoxide detector with a digital display can be very effective. It will alert you to increases in CO levels in your home as they occur, so you can address the issue before the gas reaches a lethal level.
A detector without a digital display will not beep until the situation is an emergency requiring immediate evacuation.
In order to ensure that a carbon monoxide detector is effective, the alarm must be loud enough to awaken and alert the entire household. Detectors listed by Underwriters Laboratories (UL) are verified to have a minimum 85-decibel alarm that’s audible within 10 feet of the unit.
However, as Allen, our indoor cleaning expert, points out, “Alarm sound or decibel levels are important but are measured near the device. If you are far away from the device, the sound is less audible.”
That’s why it’s important to have more than one carbon monoxide detector in a larger home or apartment. You need to be able to hear the alarm no matter where you are in the space.
If you have issues with hearing loss, you can find carbon monoxide detectors with alarms that vary their frequencies, making them easier to hear.
You can also find carbon monoxide detectors with strobe lights. This type of signal is helpful for those who are fully hearing impaired.
Some carbon monoxide detectors have voice alarms. This can be helpful in a household of deep sleepers. Children, in particular, may benefit from a voice alarm, as they may sleep through a beeping sound.
Many carbon monoxide detectors run on battery power, which allows them to operate even during a power failure. The batteries must be replaced at least annually to ensure that the detector is always in proper working order. Many models chirp or beep to let you know that the batteries are running low.
There are some battery-operated carbon monoxide detectors that use lithium batteries, which can last the lifespan of the detector.
Other carbon monoxide detectors plug into outlets, and some models can be hard-wired into your home’s circuitry for power. Neither of these types can run if there is a power failure, however.
To ensure that your home is always safe, both plug-in and hard-wired carbon monoxide detectors should have a battery-backup.
The First Alert CO615 can be plugged into any standard outlet, mounted on a wall with a six-foot power cord, or operated by two AA batteries. If one area of concern doesn't yield higher-than-average carbon monoxide readings, the entire unit can be easily removed and installed in another area. This flexibility can help save lives.
If you have a large home, having multiple carbon monoxide detectors is a necessity.
For the very best results, it helps to choose models that can be interconnected. When one detector goes off, all of the interconnected CO detectors go off, ensuring that the entire household hears the alert.
To ensure that your carbon monoxide detectors are in proper working order, they should be tested once a month.
Ideally, your CO detectors will each have a test button. You can depress the button to make sure the alarm would actually sound in the event of an emergency.
Some carbon monoxide detectors fulfill additional functions, such as smoke and/or natural gas detecting.
These devices can be convenient because you don’t have to install multiple detectors of different types throughout your home.
However, as our expert Allen explains, “Depending on detection sensitivity, dual-purpose alarms may be less effective than single-purpose alarms, as the properties of contaminants are different.”
The sensors in a carbon monoxide detector will wear out over time. In most cases, you can expect your detector to have about a five-year lifespan.
Look for a CO detector with a five-year warranty to ensure that you’ll get the best performance from your investment.
You may also wish to choose a higher-end CO detector with an end-of-life timer to let you know when it is no longer effective.
Air Quality Analysis
The Sensorcon Inspector Carbon Monoxide Tester & Meter performs one task especially well: the real-time analysis of air quality. While other CO detectors don't register readings below 30 PPM or provide accurate readings above 450 PPM, the Sensorcon Inspector can record CO levels from 0 to 2,000+ PPM. Considering how incredibly toxic a CO reading of 2,000 PPM would be to humans, we strongly urge users to wear respirators and other protective equipment before measuring CO levels of this magnitude.
Not changing batteries is a major issue for carbon monoxide detectors, so opt for long-life batteries as opposed to AAs or the like. For hard-wired units, choose models with long-life power cells.
Use a white sticker label and write the date when the unit and/or battery was installed. Then mark your calendar to check/replace the unit or battery when it nears the end of its life.
Carbon monoxide detectors vary in price based on their power sources and features, but you can typically expect to spend between $19 and $130.
For a basic, effective plug-in detector, you’ll usually pay between $20 and $45.
For a hard-wired detector or series of detectors, you’ll usually pay between $45 and $100.
For a higher-tech CO detector with plenty of additional features, you’ll usually pay between $100 and $130.
We like the fact that the Kidde KN-COPP-B-LPM's control panel offers a button for everything. Other CO detectors of this type often employ multi-functional buttons that require users to tap through various options before they get the display they seek. The Kidde’s display panel has a button dedicated to a maximum "peak level" reading between resets. Another button controls testing and resetting, and yet another controls the unit's power status. If CO levels reach toxic concentrations, an audible alarm sounds, and a small light on the control panel begins to glow.
Children are especially vulnerable to carbon monoxide poisoning because their bodies are smaller. Make sure that there is a carbon monoxide detector outside each child’s bedroom.
Situate your carbon monoxide detector in a spot where it will wake you if the alarm goes off at night.
Install carbon monoxide detectors on every level of your home.
If you have a digital-display carbon monoxide detector, install it at eye-level so it’s easy to read.
Test your carbon monoxide detectors at least once a month to ensure they’re working properly.
Most manufacturers recommend replacing the batteries in battery-operated carbon monoxide detectors at least once a year. If you hear your detector beeping or chirping, replace the batteries immediately.
Replace your carbon monoxide detector every five years – or sooner if necessary.
If your carbon monoxide detector sounds an alert, immediately go outside for fresh air. Make sure that everyone in the home, including pets, evacuates.
Ensure that the entire household understands the difference between the sounds of the carbon monoxide detector and the smoke detector. This way, your family will know whom to call for an emergency and what to tell them.
Battery-operated and plug-in carbon monoxide detectors are easy to install yourself. A hard-wired detector must be installed by a professional.
Have your furnace or heating system checked regularly by a qualified technician to ensure it’s in proper working order. This can help reduce your risk of carbon monoxide poisoning.
Q. What is the appropriate number of carbon monoxide detectors for a home?
A. This depends on the layout and size of the home. You should have at least one CO detector on every floor. That said, it’s a good idea to place one outside every bedroom so each member of the household is sure to hear the alert if it sounds.
You should also place a carbon monoxide detector within 15 to 20 feet of your furnace or any fuel-burning heat source.
Q. Is a digital carbon monoxide detector safer than other types of carbon monoxide detectors?
A. A digital carbon monoxide detector is often the best option for keeping your home safe because it shows you when carbon monoxide, even a tiny amount, is present. This could allow you to respond before the carbon monoxide reaches a dangerous level.
Q. What should I do if my carbon monoxide detector sounds an alert?
A. Immediately evacuate your home. If anyone in the household is experiencing symptoms of carbon monoxide poisoning, call 911 from a cell phone or neighbor's home. If no one is experiencing symptoms, call the local fire department or a qualified technician so your home can be inspected. If you’re not able to evacuate your home, open as many windows and doors as possible and call for help. You should also turn off any possible sources of carbon monoxide if you can.
BestReviews wants to be better. Please take our 3-minute survey,
and give us feedback about your visit today.