There are 2 heater elements in Triton showers activated via microswitches.I have had recurrent problems with these switches overheating and so failing.If one switch is failing , which is usually the case then only one heater element is activated so you have to reduce the water flow to get warm enough water. When the switches first start to fail the problem can appear intermittently. It is usually obvious by looking at the switches if there is an overhaeting problem. The microswitches are readily available.
rowan
November 2009