CO 101: Everything You Need to Know About Carbon Monoxide Detectors

Written by | Updated July 20, 2016

Carbon Monoxide 101- Everything You Need to Know About CO Detectors

Carbon monoxide (CO) is referred to as the silent killer, and the moniker is justified — the deadly nature of this odorless, colorless, tasteless gas makes it an invisible assassin. Every year in the U.S., carbon monoxide poisoning sends over 20,000 people to the emergency room. Many home appliances and commonly used items — such as ovens, cars, and lawn mowers — emit CO. If they are operated in an enclosed space or malfunction, the CO levels can become toxic.

Thankfully, most states require a CO detector in every dwelling. Though they are inexpensive, easy to install, and last a long time, they do require some upkeep. Here’s everything you need to know about keeping your family safe with CO detectors.

Why You Need a Carbon Monoxide Detector

A carbon monoxide detector operates similarly to a smoke detector — it is a stand-alone unit with a built-in alarm that will loudly sound if CO levels become too high. The best CO detectors will also monitor the CO levels in your home and display them for you on a screen. Low levels of CO can be hazardous, so it’s important to be able to monitor your home’s level at all times.

According to the Consumer Product Safety Commission, CO levels above 70 parts per million (ppm) are dangerous — if this occurs, you may experience headache, fatigue, and nausea. Levels between 1 and 70 ppm rarely cause symptoms, except possibly in people with heart conditions who may feel chest pain. CO concentrations above 200 ppm can cause disorientation, unconsciousness, and death. As carbon monoxide can cause a variety of effects at different levels, a CO detector with monitoring capabilities is highly recommended.

Installing a Carbon Monoxide Detector

The National Fire Protection Agency (NFPA) advises that CO detectors should be installed on every level of a building, outside each sleeping area, and in all locations required by state and local law. Apartment complexes and homeowners associations may have their own rules, too. Safety professionals also recommend that CO detectors be installed at least 15 feet away from any fuel-burning appliances. It doesn’t matter how high a CO detector is installed because carbon monoxide and air blend together equally.

CO detectors that simply plug into a wall can be self-installed. However, while hard-wired CO monitors can be installed with some DIY skills, a professional electrician will be able to connect it quickly and accurately.

Maintaining a Carbon Monoxide Detector

A CO detector will last around 5–10 years. Maintaining regular upkeep ensures that your carbon monoxide detector will properly recognize and alert you to dangerous CO levels.


The NFPA recommends testing CO detectors once a month, while Kidde — a fire safety product manufacturer — recommends testing once a week. To test your carbon monoxide detector, press the unit’s test or reset button.


Unplug and remove your carbon monoxide detector monthly to vacuum it or wipe it clean. This will help guarantee that the CO sensor is able to properly measure carbon monoxide levels.


Your heating system, air vents, and chimney should be inspected annually by a technician. If any of these appliances are malfunctioning, they may cause excess CO to enter your building.


Replace your CO detector based on the manufacturer’s instructions — they should include an expiration date. By regularly replacing batteries during your device’s lifespan, your detector should last at least five years.

If a Carbon Monoxide Detector Alarm Sounds

If you are in a building when a CO detector alarm sounds, immediately exit the building and call 911.

Whether you are looking to buy your first CO detector, add more for each floor of your home, or upgrade your outdated unit, there’s a lot you need to know. Check out our CO Detectors Buyers Guide for comprehensive information on the latest carbon monoxide detector models.

*SafeWise has conducted impartial research to recommend products. This is not a guarantee. Each individual’s unique needs should be considered when deciding on chosen products.


For more information on CO detectors:

*The Carbon Monoxide (CO) Detector Buyer’s Guide*


Written by Sarah Brown

Sarah Brown is a home automation and community safety consultant for She enjoys writing helpful tips and in-depth reviews. Sarah believes that through entertainment, technology and the written word, we can all stay connected to each other and create a safe environment out in the ether. Learn more

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