I have a strange problem I am struggling to resolve. My downstairs zone (timed & final door set) has stopped working on all but one door. In total 8 doors on the downstairs circuit are wired with door sensors but the system will only set on one of them the other 7 being comeptely ignored. It was fine a few weeks ago. If a wire was disconneceted then the system would never set but why does it do so on the one door? I have checked all the connections the best I can but the wiring is burried behind walls, floors and door casings. Behind the main box, if i recall correctly, there are some wires going into chocolate bars which is making me wonder if I have 2 circuits connected into a single zone. There is only one set going into the actual zone connection visible inside the man box. Hope I am making sense!!