How to Troubleshoot a Hard-Wired Smoke Alarm System

Make sure that any noise emitted by your system is not the alarm itself. Listen for an intermittent high-pitched beep every 45 to 60 seconds, as this is the sound that indicates there's a problem with the system. Evacuate the property immediately upon hearing an unprompted and incessant beeping, as this is the system alerting you to a fire.

Check each of the alarm units in the property to identify the problem unit. Use a ladder and flashlight to access and view the unit. Intermittent beeping and flashing of a small light on the unit indicates a fault with the unit.

Disconnect the circuit that powers the alarm system at the fuse box, and listen for the beeping unit. If the unit ceases beeping completely, the system itself will require inspection by a qualified electrician. Return to the problem unit if the beeping continues.

Remove the alarm unit from its housing, twisting clockwise and taking care with the hard wiring so as not to disconnect any wires. Take the cap off the unit, and remove the emergency battery. Discharge any remaining power in the unit by holding the "Test" button. The alarm should sound for 15 to 60 seconds, then go silent. Replace the battery and reattach the cap. Place the unit in the housing. Make sure it is securely fastened to the wall with no wiring visible.

Turn on the circuit that powers the alarm system and listen for any beeping. Disconnect the circuit if the beeping persists, and return to the unit. Use compressed air to clear any dust or paint residue from the unit, and reconnect the power circuit.

Return to the unit. If the beeping has ceased, test the unit by pressing the "Test" button and listening for the full alarm. If the unit sounds and then goes silent when the button is released, check the other units in the system in the same way. Should the beeping persist, contact your local fire authorities or a qualified electrician to arrange a full inspection.