Why has the carbon monoxide alarm started to chirp?
Carbon monoxide alarms chirp for various reasons – usually it is because the batteries need changing. When the battery starts to run down you will find that it normally chirps in the early hours of the morning when it is coldest. This occurs when the temperature drops the voltage to the battery automatically drops and the carbon monoxide alarm goes into low battery mode whereby the unit will chirp. When the temperature rises the chirping should stop.