I am having problems with my mira sport shower , it starts hot then goes cold and keeps on doing this, I have checked the filter which was a little dirty but made no difference. The shower head is clear and there seems plenty of power. I am not sure how to check the heating element, there are 4 electrical connections sticking out of the heater tank the nearest ones to the outside are linked with a plate, I believe these are the neutral side of the elements.I dont want to buy a new heater tank if this is not the problem, could I take elements out and descale them? I know it is long winded but I wanted to give as much information as possible