The problem

was not so much the old kettle tripping out the RCD breaker, but all the devices that had to be re-set afterwards. Oh, and I suppose there was also the risk of getting 240 volts when making the tea. The last kettle lasted about five years and was designed to inhibit any attempt to diagnose or repair faults. Moulded plug, of course, and they've changed the design of the base so the entire system has to be replaced. The older, inefficient type is still running, with an IEC standard lead, after about 20 years, relegated upstairs for hot water bottle and standby duty.