Yes thanks all fine, I went on a 70 mile trip today and all good, I think that i must have got a massive air lock in the system after losing some fluid through that temp sensor, and once it was up to the highest setting it would not come down. I left the car on the highest setting whilst away, and it came down instantly.
I think that I will ask Black C55 if he will take valve block off and try and fix, the system needs bleeding anyway so only 2 hours difference to drain and re fil