10 Best Carbon Monoxide Detectors 2026 in the United States

The First Alert BRK SC9120B-3 is a reliable choice for anyone looking to protect their home from both smoke and carbon monoxide hazards. It uses two types of sensors: an electrochemical sensor for detecting carbon monoxide, and an ionization sensor that reacts quickly to fast-burning fires. This dual-sensor approach enhances safety by covering different types of fire and gas risks.

One of the standout features is its hardwired design combined with a battery backup. This means the alarms will keep working even during a power outage, giving you peace of mind around the clock. The unit’s alert system includes an 85-decibel siren—loud enough to wake most people—and indicator lights that clearly show what kind of danger is detected.

Installation is straightforward thanks to universal mounting brackets and a tamper-resistant design, making it suitable for use in various locations around the home. The detector can also be interconnected with other compatible First Alert alarms, so if one unit senses danger, all alarms will sound, improving safety. The display is simple, with indicator lights and a single test/silence button that makes it easy to check the system or temporarily quiet a false alarm. It also comes with a dust cover to help keep the sensor clean. This 3-pack is ideal for homeowners who want dependable, long-term monitoring of both smoke and carbon monoxide with backup power, especially in larger homes or multiple rooms. Note that installation requires wiring, which might need professional help if you’re not comfortable with electrical work.

The Kidde Carbon Monoxide Detector offers a straightforward, plug-in design with a handy 9-volt battery backup to keep it running during power outages. It uses an ionization sensor, which is effective at detecting carbon monoxide and is common in many detectors. The digital LED display is a useful feature, showing you the current CO levels in your home, which goes beyond basic alarms and adds peace of mind. The loud 85-decibel alarm ensures you will hear it clearly if dangerous carbon monoxide is detected.

Installation is very easy—just plug it into any standard 120V outlet, and it can also be placed on a tabletop if needed. The included battery backup and peak memory feature, which records the highest CO level detected or last test time, provide extra safety and convenience. This 2-pack is a great value for covering multiple rooms or floors. One minor drawback is that the sensor is ionization-based, which is generally good but some users prefer electrochemical sensors specifically designed for CO detection.

Also, the unit is designed for indoor use only and has an operating temperature limit of 100 degrees Fahrenheit, so it’s best suited for typical home environments. With a strong reputation, solid safety features, and easy installation, this detector is a good fit for homeowners who want reliable, user-friendly carbon monoxide protection without complexity.

The Kidde Carbon Monoxide Detector is a plug-in device with a 9-volt battery backup, ensuring reliability even during power outages. It uses an electrochemical sensor, which accurately detects carbon monoxide and certain explosive gases like propane and methane. The digital LED display shows the current CO levels or indicates when explosive gas is detected, providing real-time information beyond just an alarm. The alarm volume is 85 decibels, loud enough to alert you effectively. Installation is simple—you just plug it into a standard 120V outlet, suitable for most homes.

The unit includes a peak level memory function that records the last CO detection or test, which is useful for monitoring safety history. However, since it relies on plugging into an outlet, it might not be ideal for locations without nearby power sockets, such as some basements or garages. Also, the temperature operating range tops at 100°F, so very hot environments might affect performance. It weighs about a pound and is compact enough to fit discreetly on a wall.

This Kidde detector covers both carbon monoxide and certain gas alarms but does not detect natural gas specifically, so checking your fuel sources is important. Backed by a 5-year limited warranty and positive customer feedback, this device is a solid choice for typical home use, especially if you want combined gas and CO detection in one unit.