BRK SC9120B Smoke & CO Alarm — Hardwired, Interconnected, Battery Backup

Two hazards, one reliable unit

The BRK SC9120B is a hardwired combination smoke and carbon monoxide alarm that runs on 120V with a built-in battery backup. It’s designed to detect two common home hazards with a single, easy-to-use device. Interconnection makes it simple to coordinate alerts across multiple rooms, so you’re alerted in more than one area of the home when a danger is detected.

Why choose this BRK model

• Inter-connectable with BRK and First Alert hardwired alarms (up to 18 devices total)
• Up to 12 smoke alarms and six other devices can be linked in a single network
• Separate visual and audible warnings for smoke and CO

Key features at a glance

• Ionization sensor optimized for flaming fires
• Microprocessor-controlled to reduce nuisance alarms
• Single test/silence button to test functionality and quiet non-threatening alerts
• Automatic internal self-test keeps the unit ready
• Latching indicators identify which unit triggered the alarm
• Tamper-resistant battery drawer lock and mounting bracket lock
• 9-volt battery backup included; 7-year limited warranty
• Easy installation with a universal mounting bracket

What it means for your home

Placed near sleeping areas as recommended by the CPSC, this unit provides early warning if CO levels rise while you rest. Clear indicators help you understand the situation at a glance without confusion.

Real-life scenarios

In living rooms, kitchens, basements, or garages, the SC9120B creates a connected safety web. If one unit detects smoke or CO, others in the series join the alert, helping you locate the hazard quickly and respond calmly.

Installation and upkeep

The plug-in power connector simplifies setup, and the 9‑volt battery backup helps maintain alerts during power outages. A chirp indicates battery status or if a tab is missing, guiding you to quick maintenance when needed.