Our boiler was moved recently and I was concerned that the electral connection form the boiler to the central heating controls was dis connected. Boiler is now wired straight to socket but I can't see how it is now linked to the central heating controls. Plumber says it is fine but if that is the case what was the previous wiring for. Can anyone suggest where I can find info on a typical diagram of a central heating system. Mine contains a copper tank, pump which is really noisy when starting up, electric valve which appears to relate to the central heating, room thermostat and gas boiler.