Hi Dave, is it a Diplomat with a white panel.If so, take off the plinth and then the silver cover at the front.Thre may be water inside.If so, this is the clicking.Water affects the pcb relay and it chatters. drain the water and reset.If the base refils, it is more than likely a leaking wash pump.The parts are about £120 plus vat and postage.All the best
FOXY, October 2008