What causes a hard wired smoke detector to chirp? Has no battery and is wired right.?
Answers:
Check again they do have a battery backup in case of power failure. depending on the type, this battery may be in all but they are all linked together so one of them has the battery backup thats weak.
Other answers:
Is there a moth on the sensor? Press the button and test the alarm to see if that works correctly. You may need to get a new one.
Is there a moth on the sensor? Press the button and test the alarm to see if that works correctly. You may need to get a new one.
maybe there's a bird stuck in it
This can be caused dust. I suggest either you clean it, or get someone professional to do so if you aren't sure how.
Good luck,
m
Mr. Home Improvement is correct. The same thing happened in my Mother's house. There are batteries in them for back up, and we had to change all the batteries in each smoke detector to stop the annoying chirp.
They are made like that . They chirp so you know that they are working.