A jumpy smoke detector

We have seven smoke detectors in our house. Since we don't systematically change the batteries yearly, we often hear a chirping noise when a battery needs changing.

Two nights ago, at around 4 am, it was not just a chirping what we heard but a shrieking real alarm with Fire! Fire! superposed into the siren sound. It eventually stopped. I tried to change the battery but that wasn't the issue.

The next day I went to the unit's manufacturer's website to research the issue, watched a video, read the PDF instructions (the electrician that did the installation trashed them and never gave them to us).

I then called the customer support number at the company which confirmed that I needed to clean each unit yearly by blowing compressed air into its vents.

I followed the instructions religiously and the following night, the same unit went berserk again at 1 am. Another piece of nice quality work from the People's Republic of China and time for a new unit, I guess.

Thanks Kidde!