most triton electric showers have two heating elements.one may not be working the cause may be 1 faulty element 2 faulty thermal cut out on outlet pipe 3 faulty wires/burnt out 4 faulty microswitches.if mains water pressure was low it would not heat up at all as there is a pressure switch on stabiliser valve.check power in off and remove cover and look for any signs of overheated wires switches connections etc
den, March 2005