First Alert BRK SC9120B-12 Hardwired Smoke and Carbon Monoxide (CO) Detector User Manual

Product Overview

The First Alert SC9120B Hardwired Combination Ionization Smoke and Carbon Monoxide Alarm with Battery Backup provides comprehensive safety by detecting both smoke from fast-flaming fires and carbon monoxide (CO) leaks. This unit is designed for hardwired installation into your home's electrical system, ensuring continuous operation with a battery backup for power outages.

Image: Front view of the First Alert BRK SC9120B-12 combination smoke and carbon monoxide detector, showing the test/silence button and smoke/CO indicators.

Key features include:

• Dual Detection: Ionization smoke sensor for fast-flaming fires and advanced electrochemical sensor for carbon monoxide.
• Hardwired with Battery Backup: Ensures continuous protection even during power failures.
• Loud Siren: 85-decibel alarm to alert occupants to danger.
• Interconnectivity: Can connect with up to 12 other compatible First Alert or BRK hardwired alarms.
• Easy Installation: Universal mounting bracket and tamper-resistant locking pins.
• Test/Silence Button: Conveniently check functionality and mute false alarms.
• Latching Indicator: Identifies which unit triggered the alarm in an interconnected system.

Installation and Setup

Proper installation is crucial for the effective operation of your First Alert detector. This unit is designed for hardwired installation.

Before Installation:

• Ensure power is turned off at the circuit breaker before beginning installation.
• Read the full installation manual (PDF link available in product documents) for detailed instructions.

Installation Steps:

1. Mounting Bracket: Attach the universal mounting bracket to the electrical junction box on the ceiling or wall. The screw holes are designed to fit most standard junction boxes.
2. Wiring: Connect the detector's wiring harness to your home's electrical system according to local electrical codes. Ensure secure connections.
3. Battery Installation: Insert the included 9V battery into the side-load battery compartment. This provides backup power.
4. Attach Detector: Align the detector with the mounting bracket and twist clockwise until it locks securely into place. Tamper-resistant locking pins help keep the alarm secure.
5. Power On: Restore power at the circuit breaker. The green LED indicator on the detector should illuminate, indicating it is receiving power.
6. Test Unit: Press and hold the Test/Silence button to ensure the alarm sounds. Refer to the "Operating Your Detector" section for more details on testing.

Image: View of the First Alert BRK SC9120B-12 detector with the battery compartment open, showing the 9V battery slot.

Image: The First Alert BRK SC9120B-12 detector installed on a ceiling in a residential setting, demonstrating typical placement.

Operating Your Detector

Normal Operation:

During normal operation, the green LED light on the detector will flash approximately once every 60 seconds, indicating that the unit is functioning correctly and receiving power.

Testing the Alarm:

It is recommended to test your detector weekly. To test:

• Press and hold the Test/Silence button located on the front of the unit.
• The alarm will sound a series of loud beeps (typically 3 beeps for smoke, 4 beeps for CO).
• Release the button. The alarm should stop sounding.

Silence Feature:

The Test/Silence button can also be used to temporarily silence nuisance alarms (e.g., from cooking smoke). Press the button once to silence the alarm for a short period. If the smoke or CO concentration is still present, the alarm will reactivate after the silence period.

Understanding Alarm Signals:

The detector uses distinct audible patterns to indicate different threats:

• Smoke Alarm: Three long beeps, pause, three long beeps.
• Carbon Monoxide Alarm: Four quick beeps, pause, four quick beeps.
• Low Battery Warning: One short chirp every minute. Replace the 9V battery immediately.
• End of Life Warning: Five chirps every minute. This indicates the unit needs to be replaced.

Image: Informational graphic explaining that carbon monoxide is an invisible, odorless, and deadly gas, and CO alarms provide early warning.

Image: Graphic illustrating recommended placement of smoke and carbon monoxide alarms: one on every level and in every bedroom.

Maintenance

Regular maintenance ensures your detector remains in optimal working condition.

• Weekly Testing: Test the alarm weekly using the Test/Silence button.
• Monthly Cleaning: Vacuum the detector cover monthly to remove dust and debris that could interfere with sensor operation. Do not use cleaning solutions or solvents.
• Battery Replacement: Replace the 9V battery annually, or immediately when the low battery chirp sounds. Even though it's hardwired, the battery backup is vital.
• Unit Replacement: Replace the entire unit every 7-10 years from the date of manufacture, or when the end-of-life warning sounds.

Troubleshooting

If your detector is not functioning as expected, refer to the following common issues and solutions:

For further assistance, consult the full user manual or contact First Alert customer support.

Specifications

Image: Side profile of the detector showing approximate dimensions: 5.6 inches in diameter and 1.9 inches in depth.

Warranty and Support

This First Alert BRK SC9120B-12 detector comes with a 7-Year Limited Warranty.

For warranty claims, technical support, or additional information, please refer to the official First Alert website or contact their customer service directly. Always keep your proof of purchase.

You can also find the full User Manual (PDF) and Installation Manual (PDF) for this product online:

• User Manual (PDF)
• Installation Manual (PDF)