Resideo co400b Carbon Monoxide Alarm Battery Operated

Product Description

The RESIDEO co400b is a battery-operated carbon monoxide alarm designed for residential installation by licensed electricians, HVAC technicians, or qualified contractors. It uses an electrochemical CO sensor, which delivers greater accuracy than semiconductor or biomimetic sensing technologies. The unit runs on a single 9V alkaline battery included in the package and features a one-button test and silence function. Two distinct silence modes allow the installer or occupant to suppress a low-battery chirp for up to eight hours or temporarily clear a nuisance alarm without disabling the sensor. An end-of-life signal provides audible notification when the unit requires replacement.

The co400b is suited for residential settings including single-family homes, apartments, and light commercial occupancies where local or state codes mandate carbon monoxide detection. It mounts to a wall or ceiling surface and is intended for areas near sleeping quarters, mechanical rooms, or attached garages per typical code guidance. The unit meets requirements for jurisdictions adopting carbon monoxide alarm mandates under state and local codes and is listed to the UL 2034 standard.

Key Features

• Electrochemical CO sensor for accurate detection compared to other sensing technologies
• Single-button test and silence operation
• Low-battery chirp silence for up to eight hours
• Temporary nuisance alarm silence without disabling detection
• End-of-life audible warning signals when unit needs replacement
• Easy-access battery compartment with replaceable 9V alkaline battery

Compatibility

Designed as a standalone battery-operated carbon monoxide alarm suitable for residential and light commercial installations requiring compliance with UL 2034 and applicable state or local CO alarm codes.

Installation Notes

Installation should be performed in accordance with the manufacturer instructions and applicable local codes, including NFPA 720 guidelines for CO alarm placement. Power down is not required for this battery-operated unit, but verify the 9V battery is fully seated before mounting. Mount the alarm to a wall or ceiling in the location specified by local code, typically near sleeping areas or fuel-burning appliances. Do not install in areas subject to extreme temperatures, high humidity, or direct airflow from vents, which can affect sensor accuracy.

Technical Specifications

• Sensor Type: Electrochemical
• Power Source: Battery Operated
• Battery Size: 9V alkaline
• Number of Batteries: 1
• Battery Replaceable: Yes
• Sound Level: 85 dB at 10 feet
• Product Height: 3.4 inches
• Product Length: 4.9 inches
• Product Width: 1.4 inches
• Product Weight: 0.45 pounds
• Color: White
• Approvals and Standards: Listed to UL 2034
• Warranty: 7 Years Limited

Standard Information

• Brand: RESIDEO
• Manufacturer Part Number: co400b