If u take the back panel off you can see the heater element.It will have aristion k99 w2000/240 stamped on it and three connections.The left connection has a brown cable connected,the middle connection has the earth connected to it and the right connection has a red and a blue cable connected to it.U can test between all off these terminals for continuity.If u have an open circuit between the outer two connections the element needs to be replaced.If u have closed circuit reading between the middle terminal (earth) and any outer terminal (live or neutral) u also need to change the heater element.U should get a low ohm reading between L+N and a very high ohm reading (eg999) between earth and L/N terminals.
Peter, December 2006