If a smoke alarm is chirping every 30 seconds consistently, the smoke alarm's battery may need to be replaced.
If you have changed the battery in your chirping smoke detector and it still chirps, you might think your detector is bad. ... With the battery removed, press and hold the test button for 15-20 seconds. Put the new battery back in the detector and restore power to the circuit breaker.
Press and hold the test button on the smoke detector. It can take a few seconds to begin, but a loud, ear-piercing siren should emanate from thesmoke detector while the button is pressed.