First Alert Carbon Monoxide Detector CO605 — Plug-in White with Battery Backup and Electrochemical Sensor

The First Alert CO605 is a plug-in carbon monoxide detector with an electrochemical sensor and battery backup that monitors CO continuously and sounds an 85 dB alarm when levels become hazardous.

This compact white CO alarm is designed to plug into any standard outlet for continuous protection, while its sealed electrochemical sensor provides accurate detection without complicated settings. A built-in battery backup keeps the unit operational during power outages, and a single multi-function button tests the alarm and silences nuisance alerts. With a 7-year limited warranty and UL testing, this model focuses on straightforward, room-by-room safety.

How does the CO605 detect carbon monoxide accurately?

The CO605 uses an electrochemical sensor, the preferred technology for CO detection because it reacts specifically to carbon monoxide molecules. That sensor converts gas exposure into an electrical signal the device evaluates, reducing false alarms compared with older sensing methods.

• Electrochemical sensor for targeted CO detection
• Sealed design helps maintain long-term accuracy
• UL-tested to meet recognized safety standards

What keeps the alarm working during a power outage?

In addition to plugging into a standard outlet, the CO605 includes a battery backup that powers the unit when mains power fails. The low-battery signal can be muted temporarily to prevent repeated chirps while you plan a battery replacement.

• Battery backup ensures continuous monitoring during outages
• Low-battery mute silences the signal for up to 8 hours
• Single button lets you test function and silence nuisance alerts

How loud is the alarm and when will it sound?

The detector produces an 85-decibel alarm designed to wake sleeping occupants and alert people throughout nearby rooms. It will sound when CO concentrations reach levels that the sensor deems potentially dangerous and includes both test and silence functions for controlled response.

• 85 dB alarm for clear audible warning
• Instant sound activation when elevated CO is detected
• Test button verifies proper operation on demand

Where should I install the CO605 for best protection?

Place one CO605 on every level of your home and inside each sleeping area for comprehensive coverage. Because it plugs into a standard outlet, position it where it remains unobstructed and within audible range of bedrooms.

• Install on each floor and in every bedroom for full coverage
• Plug directly into an outlet; no mounting hardware required
• Avoid blocked vents, tight cabinets, or locations with heavy dust

Who is this for: The First Alert CO605 is suited to homeowners and renters who want a simple, reliable CO detector that installs without wiring. It’s ideal for people who prefer plug-and-play devices, need battery-backed protection for power outages, and want a long-life electrochemical sensor with an end-of-life signal and a 7-year limited warranty.