Yes, I do believe this is the problem but I did get a new O-ring and one of the staff installed it (ordered the part from the manufacturer) so either it was installed incorrectly of possible another problem.
Beginning to think I am better off getting someone in who knows what they are doing!
And as for my flat white......I went to a café lol
Oh and talking coffee is more interesting tha, talking about......what was the question again?