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

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.

The First Alert SMCO100 is a battery-operated combo alarm that protects against both smoke and carbon monoxide, making it a practical choice for home safety. It uses photoelectric sensors, which are especially good at detecting smoldering fires and reducing false alarms from cooking. This means fewer annoying nuisance alarms compared to traditional models.

Since it runs on 2 included AA batteries, installation is simple and you don’t have to worry about wiring, though you will need to replace batteries periodically. The alarm includes a test/silence button for easy checks and temporarily silencing false alerts. It also has an end-of-life warning that notifies you when it’s time to replace the unit, helping to ensure ongoing protection. The 3-pack offers good value for covering multiple rooms or floors. However, since these smoke/CO detectors are not interconnected, alarms won’t sound simultaneously throughout the house if one detects danger, which could be a drawback for larger homes.

This First Alert model provides a reliable, user-friendly option for those seeking straightforward, battery-powered smoke and carbon monoxide detection without extra complexity.

The FIRST ALERT BRK SC9120FF is a reliable hardwired smoke and carbon monoxide detector that comes with a battery backup to keep it working during power outages. It uses two types of sensors: an electrochemical sensor specifically for carbon monoxide and an ionization sensor for detecting smoke. This combo means it can quickly alert you to both fire and dangerous gas, which is important for home safety. The alarm is loud at 85 decibels, ensuring you can hear it clearly in an emergency. One helpful feature is the indicator lights that show whether smoke or carbon monoxide has been detected. It also can connect with other compatible alarms in your home, so if one senses trouble, all alarms will sound together, giving broader protection.

Installation is made easier with universal mounting brackets and tamper-resistant locking, though since it’s hardwired, it may require some basic electrical work or professional installation. The device is designed to last a long time, supported by a 10-year limited warranty, and includes a 9-volt battery for backup that you’ll need to replace periodically. The unit is straightforward to test and silence with a single button. While this alarm may be more complex to install compared to battery-only models, it is a solid choice for homeowners looking for dependable, continuous protection combining smoke and CO detection with the added safety of battery backup and interconnectivity.