Most hard-wired smoke detectors use a 9-volt battery that is supposed to kick in if your home loses electricity. When that battery is running low, your detector alerts you with a chirp that it's running low. Replacing the battery solves the problem. Smoke detectors sit on your ceiling or walls and accumulate dust.

How do you stop a hardwired smoke detector from beeping?

Hard-wired smoke detectors (which typically include a backup battery) are subject to similar issues as those that operate on a battery only. However, hard-wired units often require resetting after problems are addressed. Simply hold the reset button for 15 to 20 seconds to silence the noise.

Why is my hardwired smoke alarm beeping every 30 seconds?

If your smoke alarm is emitting a single high-pitched chirp every 30 seconds or so, it's most likely a sign that the battery is running low and needs to be replaced. Stopping the problem is a simple matter of changing it out.