"sbb" wrote in message
...

What will connecting mains water do to the hot feed ? and do you mean
turn the mains back on which will cause the cold tank to fill and then
connect a mains supply to the shower head.


Connecting mains to the pump output will blast air back into the cold water
tank, and the hot water tank, by setting the thermostaic valve to cold and
hot respectively. It'll also prime the pump if it's necessary.