I had the same problem and ours has been disconnected for ages! I do have another one half way up the stairs though so i didnt worry too much!!!!! Yesterday I had a home safety check from our local fire brigade and when i asked them about it, they said it was in the wrong place and I should have one in the hall and one at the top of the stairs! They fitted me two free of charge! If you get in touch with your local fire service they may well do the same check and fit you some new ones!