Klurgen said:
Sorry so cold water was working ok filled hot water tank and heated it on electric when I put tap on tripped electric replaced fuse now there is no water at all tested pump it's ok sorry for being so vague first time
Still doesn't quite make sense.
I assume:-
The 12V pump was working and fed cold water through the taps.
You used 12V pump to fill water heater (which it should have done automatically)
You heated the water using 230V electricity
When the water was hot you turn on a tap and something tripped - was that 230V or 12V?
This sounds like the 12V power supply has failed (or its fuse has) and you don't have a battery fitted. Is that correct?