Having reset the MCB my electric shower is now not heating the water fully, why?
The most likely reason why the unit is not heating the water fully is that a heating element has failed. The elements can be tested for continuity using a multi-meter. If open circuit a new heater assembly is needed. Note: If an element has failed other parts within the unit may have been affected it is therefore important to check all the electrical circuits in the unit for signs of failure.