Question:
BRK 4120B smoke alarm chirps The BRK 4120B has been removed and yet chirps still emanate from the wiring in the ceiling at regular (somewhat long) intervals. What is happening and how can I repair it?

Answer: -"Chirps" from the wiring?? You sure you don't have birds nesting in the attic?? Your BRK smoke alarm may have a battery inside. Remove that and the "chirping" should stop. I've also noticed that some BRK AC smokes will continue to chirp intermittently for a few minutes *after* you disconnect them from power.

-Would it be possible that you have something else doing the chirps? Like an old 9 volt battery smoke detector that is in a drawer and the battery still connected? or an unused paget? whats on the next level?(on top of the ceiling)..could there be a bird nest there?(in the attic if so).. maybe you have an old smoke detector in the attic..wich have a low battery? one other thing...some sirene can make a small sound when the alarm panel prob it(to see if its still there)one way to fix this problem is to put an end of line resitor at the sirene cable end..