I have a hard wired smoke detector which is misbehaving and going off at

[ViolatedMeppae]

inappropriate times? What could be wrong with it. The thing has no set pattern, we don't know how old it is and it is a hard wired one so it hasn't got a flat battery (well, has it?). My partner went up in the roof to check and make sure that nothing was amiss up there and it was fine. You can push the button on the top of it to resent it and it just goes off again. Can anyone help us?