Hi,Final update...Pressure sensor was the culprit, although aparrantly the sensors look oily when they fail, mine was as new! So sensor replaced, system vacuum tested, all ok, re gassed and checked for leaks using sniffer, no leaks! Air con now is icy cold and sorted. Total bill was £266, which also included a cvbootreplacement whilst the car was in.Hope this might help someone in the future, Happy days!Thanks to all, Woody