Tony, just a quick email to thank you most sincerely  for your professional help and support today in solving the water supply problem in our 2013 Elddis Avente caravan.
The problem has been raised with the dealer on each service , and also when the caravan was only 6 weeks old, they kept the van for 31 days ” to solve the problem” the fault was exactly the same when returned.
As I explained to you although I expressly asked at the last dealer service to solve the water problem,the water system was not even checked off, on the service report.
At times they just dismissed the issue as air in the system.
Indeed it was as you found out,  air in the system as the sealing o rings were the problem allowing the air to enter.
Best wishes
Mike and Jan R,  East Yorkshire
― Problem solved after five years!