Ok, i called stack today and spoke to Pete, the same chap as matey spoke to yesterday.
He basically said they will power it up and test it with a calibrated pressure tester.

If it was faulty they wont repair it due to its age.

So i emailed matey to tell him to send it to me, i will test it and go from there.

Had a reply just now saying his electrician mate has just been round, it was a bad earth and it now works as it should!

If he had done as i said and tested it off the battery all this shite would have been avoided lol.

Job done