2001 AVONDALE DART 510/5L
I DONT KNOW THE ANSWER YET BUT WORKING ON IT ON UK CAMPSITE EVERYONES PUTTING IT DOWN TO NON RETURN VALVE OUR IS DOING THE SAME AS YOURS BUT WE SOMETIMES GET A BURST OF WATER LOOK ON UK CAMPSITE AT MESSAGES THEN WATER AND THE FORUM IS CARAVAN GREAT PEOPLE ON THERE. I HAVE THE PUMP THAT GOES INTO AQUAROLL AND THE AQUASOURSE THAT FITS ONTO VAN AND MAINS TAP AND THERE BOTH THE SAME SO MUST BE IN THE VAN BUT WE CANNOT FIND THE NON RETURN VALVEDO YOU KNOW WHERE IT IS ?
LIZ WILKINSON, October 2007