10 Best Smoke Detector Carbon Monoxide Detectors Combo 2025 in the United States

The First Alert BRK SC9120B-3 is a solid choice if you're looking for a dependable smoke and carbon monoxide detector combo for your home. It uses two types of sensors: an electrochemical sensor for carbon monoxide, which is very effective at detecting this dangerous gas, and an ionization sensor that quickly spots smoke from fast-burning fires. This dual sensor setup means it covers both slow and fast fire types well.

Power is a strong point here since these detectors are hardwired into your home's electrical system but also include battery backup. That means they keep working even if the power goes out, giving you constant protection. Installation is straightforward with universal mounting brackets and tamper-resistant locking, which is helpful for peace of mind. The alarm itself is loud at 85 decibels, enough to wake most people, and the unit has clear indicator lights to show if smoke or carbon monoxide is detected. It also has a simple test and silence button, which makes maintenance easier. Plus, these alarms can be interconnected with other compatible First Alert units, so if one detects a problem, all alarms in your home will sound – a useful feature for larger houses.

While it comes with batteries included, these are 9-volt alkaline batteries which will need regular checking and replacements over time to ensure the backup power remains effective. The detectors have a standard lifespan typical for these devices, so you’ll want to replace them every 7-10 years to maintain safety. Some users might find the 5.6-inch size a bit bulky compared to newer, slimmer models. If you want a reliable, easy-to-use smoke and CO combo detector with hardwired power and battery backup, this 3-pack from First Alert offers great value, especially for families or multi-room setups. It balances strong detection technology with user-friendly features, making it well-suited for most homes seeking comprehensive safety monitoring.

The X-Sense Wireless Interconnected Combination Smoke and Carbon Monoxide Detector (SC06-W, 6-Pack) offers a robust solution for home safety. Its dual protection with photoelectric smoke and electrochemical CO sensors ensures comprehensive hazard detection. The standout feature is its wireless interconnectivity, allowing all alarms to sound simultaneously if one is triggered, which can significantly enhance safety throughout a home.

It’s important to note that this device doesn’t support Wi-Fi, which limits remote monitoring capabilities. The 10-year sealed battery is a strong point, offering a long-term power solution without the need for frequent battery changes, though it will give a low battery warning towards the end of its lifespan. The inclusion of a test/silence button is a practical touch, making it easy to check functionality or silence alarms if needed.

This model supports full home coverage by linking up to 24 units, ensuring extensive protection. Since it’s battery-powered, there may be concerns about battery disposal, and the lack of Wi-Fi means users can’t receive alerts on their phones. This detector is ideal for users seeking a reliable, interconnected alarm system with long battery life, but it may not suit those looking for smart home integration features.

The Kidde Smoke & Carbon Monoxide Detector 2-pack is a practical choice if you're looking for an easy-to-use device that covers both smoke and carbon monoxide detection. It combines photoelectric and electrochemical sensors, which helps it detect smoke from fires and dangerous carbon monoxide gas effectively. One big plus is its 10-year battery life — you won't need to worry about changing batteries or annoying low-battery chirps for a decade, which also saves money over time. Installation is simple since it’s battery powered and wireless; just mount it on the ceiling and click it into place. It has clear LED lights to show its status, so you can easily see if everything's normal, if there's a problem, or if an alarm is sounding.

The 85-decibel alarm is loud enough to alert you even if you’re in another room. It also features a test and hush button, handy for checking the alarm works or silencing false alarms, which are less common thanks to its improved sensing technology that reduces alerts from normal cooking smoke. However, it doesn't support interconnectivity, so multiple alarms won't communicate with each other, which might be a drawback if you want whole-home coverage with linked alerts. Its operating conditions are quite standard, suitable for typical home environments.

This detector is ideal for homeowners who want a reliable, low-maintenance, combo smoke and CO alarm without complicated wiring or smart home features. It has a solid warranty and customer feedback supports its dependable performance, though after 10 years, the entire unit needs replacing, not just the battery.