WD71 keeps leaking?

Sorry, I posted this for the WD72, but ours is actually a WD71, so I'm trying again.

Hi, This has been leaking for some time now. At first I thought it was because the outlet pipe was blocked (I kept getting the 'check outlet pipe' error). So, I took all that apart, including the condenser and cleaned everything out.
But, it still leaks. I have found out that it's where the cold water pipe connects into the machine. It's actually one of the black electrical 'things' (sorry, no idea what it's called or how to describe it) just inside the machine where the cold water pipe enters the machine there are three pipes leading off a plastic 'junction'.
It seems to be from the 'black box' bit itself.
So, the questions are :
Has anyone else experienced this?
What is that part called so I can try to order a replacement?

I'm actually thinking of scrapping the machine as it's been nothing but trouble from day one (had to get a replacement as the first one we had kept blowing the electrics) and the service engineers were soooo bad! It's run out of warranty now and there's no way I'm calling those service engineers up and actually paying them!