1. Introduction
The First Alert SMI100 Battery-Operated Smoke Alarm is designed to provide early warning of smoke and fire hazards in your home. Equipped with Precision Detection advanced sensing technology, it aims to reduce nuisance alarms from cooking while ensuring reliable detection of actual fires. This manual provides essential information for proper installation, operation, and maintenance to ensure the safety of your household.
2. Key Features
- Precision Detection Technology: Advanced sensing technology designed to reduce cooking nuisance alarms and provide early warning of home fire emergencies.
- Battery-Operated: Allows for easy installation without complex wiring.
- Front Access Battery Compartment: Facilitates easy battery replacements.
- End-of-Life Warning: Alerts you when the unit needs to be replaced.
- Test/Silence Button: For efficient testing of alarm functionality and silencing nuisance alarms.
3. Setup and Installation
Proper placement and installation are crucial for the effective operation of your smoke alarm. Follow these steps carefully:
- Unboxing and Components: Open the packaging and ensure all components are present: the smoke alarm unit, mounting bracket, 9V alkaline battery, and screws/anchors.
- Recommended Placement: Install smoke alarms on every level of your home and in every bedroom. Avoid placing alarms near cooking appliances, heating vents, or bathrooms to minimize nuisance alarms.
- Mounting the Bracket: Use the provided screws and anchors to securely attach the mounting bracket to the ceiling or wall. Ensure the bracket is firmly in place.
- Activating the Battery: The smoke alarm comes with a pre-installed 9V battery. To activate it, pull the plastic tab from the battery compartment. The alarm will chirp once to indicate activation.
- Attaching the Alarm: Align the smoke alarm unit with the mounting bracket and turn it clockwise until it locks securely into place.
- Testing the Alarm: Press and hold the Test/Silence button on the front of the alarm until you hear a loud, pulsating alarm sound. Release the button. This confirms the alarm is functioning correctly.

Figure 1: Installation of the First Alert SMI100 smoke alarm on a ceiling.
Video 1: Step-by-step guide on how to install the First Alert SMI100 smoke alarm.
4. Operating Instructions
The First Alert SMI100 is designed for simple operation and clear alerts.
- Power Indicator LED: A small LED light on the alarm's front will flash periodically (approximately every 30-60 seconds) to indicate that the alarm is receiving power and functioning correctly.
- Test/Silence Button: Press and hold this button to test the alarm's functionality. The alarm will sound a loud, pulsating tone. To silence a nuisance alarm (e.g., from cooking smoke), press this button once. The alarm will temporarily silence for several minutes before resetting.
- Alarm Sound: In the event of smoke detection, the alarm will emit a loud, continuous, pulsating sound. Evacuate the premises immediately and call emergency services.

Figure 2: Front view of the First Alert SMI100 smoke alarm, showing the test/silence button and power indicator.
5. Maintenance
Regular maintenance ensures your smoke alarm remains operational and effective.
- Weekly Testing: Test your smoke alarm weekly by pressing and holding the Test/Silence button until the alarm sounds.
- Battery Replacement: When the 9V battery is low, the alarm will chirp approximately once every minute. To replace the battery, open the front-access battery compartment, remove the old battery, and insert a new 9V alkaline battery. Close the compartment securely.
- Cleaning: Gently vacuum or use compressed air to clean the smoke alarm monthly to remove accumulated dust or debris that could interfere with its operation. Do not use water, cleaners, or solvents.
- End-of-Life Replacement: Smoke alarms do not last forever. The SMI100 has an end-of-life warning that will indicate when it's time to replace the entire unit, typically after 10 years from the manufacture date.

Figure 3: The front-access battery compartment of the SMI100 for easy battery replacement.
6. Troubleshooting
If your smoke alarm is not functioning as expected, refer to the following common issues:
| Problem | Possible Cause | Solution |
|---|---|---|
| Alarm chirps once every minute | Low battery | Replace the 9V battery. |
| Alarm chirps 5 times every minute | End-of-life warning | Replace the entire smoke alarm unit. |
| Alarm sounds frequently without smoke | Nuisance alarm (cooking, steam, dust) | Press the Test/Silence button. Clean the alarm and relocate if necessary. |
| Alarm does not sound during test | No power or malfunction | Ensure battery is correctly installed and activated. Replace battery. If problem persists, replace unit. |
For additional troubleshooting, refer to the detailed instructions printed on the back of the alarm unit or consult the full user manual.

Figure 4: The back of the SMI100 unit provides quick reference for activation, deactivation, and maintenance.
7. Specifications
| Specification | Detail |
|---|---|
| Model Number | SMI100 |
| Brand | First Alert |
| Power Source | Battery Powered (1 x 9V battery included) |
| Sensor Type | Ionization |
| Color | White |
| Item Weight | 9.6 ounces |
| Product Dimensions | 5.6 x 5.6 x 1.9 inches |
| UPC | 029054022400 |
| Manufacturer | Resideo |
8. Warranty and Support
The First Alert SMI100 Smoke Alarm comes with a 10-year limited warranty, ensuring long-term reliability and peace of mind. For technical assistance, troubleshooting, or warranty claims, please contact the Customer Service Team.
Customer Service Team: 1-800-323-9005
For more information, visit the official First Alert website: firstalert.com







