Apologies if these has already need covered. Here's what I discovered.
As highlight by some of the member above, the issue for me was the taps micro switch, this needed cleaning.
When I looked at it (I gently pulled the tap hand off), it didn't look particularly dirty. But this should be silver, not bronzy (I think).
I used a tooth pick with some WD40 on the tip to scratch it off.
Something worth noting though is the small "U" shaped spring like thingy. This is the part of the micro switches mechanic that helps to make the click sound (I think). This is under tension and if you remove it, it will ping off. Be warned, if you lose this you might need to by a whole new tap! I guess try and not remove it. You need good eye site to get it back on again.
I've tried to capture where this is below. The blue shape is my attempt to show the the shape of this piece. It's like a "U" as I mentioned with 2 very small holes either side to hold it in place.
Note the position of the tap when you pull this off. There are grooves in the white plastic rod that align to the mouldings on the inter of the tap.
View attachment 92412
Also some else worth nothing.
I did change the water pump. The new pump is now so strong at drawing water, the hose from the pump that exits the tank, often pulls off the out let tube, due to the high pressure. This wasn't helped by the fact I allowed the water pump to sit freely in the tank.
I moved the pump in-between the 2 nubs seen in the below (this might be where it is supposed to this anyway?) and this helps reduce movement from the pump. But if I turn on the tap too fast and open the switch too much, the hose pulls off the inner outlet.
I'm hoping a hose clip will fix this issue.
View attachment 92414
Any where thank you all very much for all the advice on this thread. It's need a great experience and I've learnt something new. Also saved myself £400 by avoiding VW!