Save 10% off your next order
Help
Order Tracking
Save 10% off your next order - See How
Customer ServiceHelp
Products
Smoke & Fire
Carbon Monoxide
Other Safety

How to Replace Your USI-1204 Smoke & Fire Alarm

The USI-1204 was a staple in home safety for years, but like all smoke alarms, these units must be replaced every 10 years. If your unit is aging or chirping, transitioning to a modern, compatible model like the USI-5304 or the Sensing Plus® series ensures your family remains protected with the latest technology.

Safety First: Hardwired smoke alarms operate on 120V electricity. Always turn off the power at the circuit breaker before beginning the replacement process.

Step-by-Step Replacement Instructions

1. Power Down & Remove

Turn off the electricity to the smoke alarm circuit. Confirm power is off by checking that the green LED light on the alarm is no longer lit. Twist the USI-1204 body counter-clockwise to remove it from the mounting base and unplug the old wire harness.

2. Expose the Wiring

Unscrew the USI-1204 base from the wall or ceiling. Note: Leave the screws in the electrical box; you will reuse them for the new bracket. Gently pull the wires down to expose the wire nuts. Unscrew the nuts to fully disconnect the old harness.

3. Install the New Bracket

Install your new mounting bracket (included with models like the USI-5304) using the existing screws. Unlike older models, new USI alarms feature a Quick Connector. Use wire nuts to connect the corresponding house wires to the new harness (usually Black to Black, White to White, and Yellow to Yellow for interconnect).

4. Connect & Test

Plug the quick connector firmly into the back of the new alarm until it snaps. Twist the alarm onto the bracket. Once all units in the home are installed, flip the breaker back on. Ensure the LED is green and press the Test Button to confirm operation.

Choosing Your Replacement Model

Depending on your budget and safety needs, there are three primary models recommended for replacing the USI-1204:

MP116S: The Standard

The direct successor to the 1204. Wired directly into your home's electrical system, this alarm eliminates the risk of power loss (with a battery backup) and the hassle of changing batteries. Interconnectable with up to 24 compatible USI Electric alarms and devices.

View Product
AMI1061SB: Sensing Plus®

Uses AI to distinguish between real fire smoke and "nuisance" smoke from cooking or steam. Fully compliant with UL 217 8th Edition standards. Maintenance free, provides 10 years of safety protection.

View Product
AMIC1510SB: Combination Alarm

provides 10 years of continuous protection against deadly threats in the home. New Sensing Plus® Multi-Criteria Detection provides the benefits of both photoelectric and ionization alarms in one device to protect against fast flaming and slow smoldering fires.

View Product

Why Upgrade to Sensing Plus® Technology?

The newest generation of Universal Security Instruments alarms (like the AMI1061SB) utilize advanced microprocessors to classify smoke profiles. By upgrading today, you benefit from:

Watch The Video

Quick Install Guide

  1. Power Down: Flip the breaker and confirm the green LED is off. Twist the old unit off the base and unplug it.
  2. Disconnect: Unscrew the old base (keep the ceiling screws!). Pull down the wires and unscrew the wire nuts to remove the old harness.
  3. Wire New Harness: Screw the new bracket into the existing holes. Match and secure the wires (Black to Black, White to White, Yellow to Yellow) using wire nuts.
  4. Snap & Test: Plug the connector into the new alarm and twist it onto the bracket. Restore power and press the Test Button to confirm.
0 $0.00
Top