10 Best Carbon Monoxide Detector 2025 in the United States

This NICGOL 4-in-1 carbon monoxide and natural gas detector stands out with its combined ability to monitor CO, natural gas leaks, temperature, and humidity, using catalytic sensors. It plugs into a standard AC outlet, avoiding the need for batteries, which makes it convenient for continuous use in homes, RVs, or similar spaces. The detector features both loud (≥85 dB) sound alarms and flashing red lights to quickly notify you of dangerous gas levels, which is especially useful in noisy environments or for those with hearing difficulties.

Its colorful LCD screen clearly displays real-time gas concentrations, temperature, and humidity, helping you stay informed about your environment. The included test button lets you easily check alarm functionality, which is important for safety confidence. It’s energy-efficient with low power consumption and compact enough not to clutter your space.

With very positive customer ratings and a reputable sensor type, this detector is a solid choice for those needing multi-gas detection in homes or mobile settings, though buyers looking for networked alarms or detailed warranty coverage may want to explore other options.

The First Alert SMICO100-AC Combination Smoke and Carbon Monoxide Alarm is designed to provide reliable protection for your home. With its ionization sensor, it detects smoke and carbon monoxide effectively, offering dual protection. The hardwired unit comes with a battery backup, ensuring continuous operation during power outages, which is a significant advantage for safety.

Its interconnectivity feature ensures that if one alarm goes off, all alarms in the network will sound, providing comprehensive coverage throughout your home. The Quick Connect Plug feature makes installation straightforward without the need for extensive rewiring, which is convenient for most users. Additionally, the test/silence button allows for easy maintenance and ensures the alarm is functioning correctly.

It is worth noting that being a hardwired unit, it requires a bit more effort during initial setup compared to battery-only models. The ionization sensor is also more prone to nuisance alarms from cooking, although the advanced sensing technology aims to minimize this. If you’re looking for a robust, interconnected smoke and CO alarm with battery backup, this could be a solid choice.

The Kidde Carbon Monoxide Detector is designed to detect carbon monoxide as well as propane, natural gas, methane, and other explosive gases, making it a versatile safety device for homes with multiple fuel sources. It plugs into a standard 120V outlet and includes a 9-volt battery backup, allowing it to continue operating during power outages for uninterrupted protection. The digital LED display provides current CO levels and alerts for explosive gases, offering clear, real-time information beyond a simple alarm sound.

It features an 85-decibel alert, loud enough to wake most people in case of danger. The Peak Level Memory function recalls the last CO level detected or the last time the unit was tested, which can be useful for troubleshooting or peace of mind. Installation is simple as it plugs directly into a wall outlet without complicated setup. This model does not offer wireless interconnectivity, so it cannot connect to other detectors or smart home systems, which may be a consideration for users seeking broader home safety integration.

The detector is compact in size and operates effectively in most home humidity conditions. This Kidde unit provides a reliable and user-friendly choice for those needing combined carbon monoxide and explosive gas detection in a plug-in format with battery backup, especially if a clear digital readout and straightforward alarm features are preferred without requiring smart connectivity.