Yes, you can mix smoke and carbon monoxide detectors, including combination units that detect both simultaneously. This is common, and even recommended, for comprehensive safety. You can choose to have separate detectors for each or use a combination unit, which is often more convenient.

Anka Security explains how to mix them:

Combination units:

These units detect both smoke and carbon monoxide in a single device. They are a convenient way to ensure both types of detection are in place.

Standalone units:

You can also use separate smoke and carbon monoxide detectors. This allows for more targeted placement based on your home’s specific needs (for example, placing a CO detector near a potential CO source like a furnace).

Interconnected systems:

Many smoke and CO detectors can be interconnected, so when one alarm goes off, all alarms in the system sound, providing a whole-house alert. This is beneficial for both combination and standalone units.

Placement considerations:

Smoke detectors are typically placed in the ceiling, while carbon monoxide detectors are recommended to be placed at breathing level (for example, a few feet above the floor). Combination units should be placed according to the manufacturer’s instructions for smoke and CO detection, which may vary.
Testing and Maintenance: Regardless of the detector type, regular testing and battery replacement (if applicable) are essential to ensure proper function.

Smoke and carbon monoxide (two in one) alarm recommended for you