I wont go in to the back story but a neighbour has a home burglar alarm installed about 5 years ago. He was never left any instrucions but it was set by the installer. Not only do I think that was deliberate so any fault would entail the installer picking up call out charges but the owner has no code to switch it off (if faulty)
Question.. should the installer legally leave instruction manual and a code to switch it off to allow a change of batteries?