How to Replace Your USI-1204 Hardwired Smoke Alarm
The USI-1204 was a home safety favorite for years. If your unit is 10 years old, it is time for an upgrade. Follow our simple guide to install a modern replacement.
Simple Steps to Install Your New USI Alarm
1. Power Down the System
Turn off the electricity at your breaker panel. Confirm the green LED on your old alarm is unlit before you start.
2. Remove the Old Unit
Twist the USI-1204 counter-clockwise to remove it from the bracket. Unplug the wiring and unscrew the mounting plate from the ceiling.
3. Wire the New Bracket
Secure the new mounting bracket to the ceiling. Use the provided quick connector to join the matching black, white, and yellow wires.
4. Mount and Test
Plug the wire harness into the new alarm and twist it onto the bracket. Restore power and press the "Test" button to confirm operation.
Why Replace an Expired USI-1204?
Smoke alarms are rated for a 10-year lifespan. Dust, humidity, and age can degrade the internal sensors. Upgrading ensures your home has the most accurate fire and smoke protection.
Find Your Replacement Alarm
Don't wait for your old alarm to fail. Browse our collection of modern hardwired alarms designed to fit your existing USI wiring.
Shop Compatible Alarms