Well, red cheeks all round! I took another look...investigated a little more and solved the problem. I was given the impression that the toilet tank was filled via the on board water tank; it isn't. I found a small trap door on the interior of the van with no label but it did have a small smear of pink loo flush on it...it doesn't look like anything I would have thought of filling as inside was a tall plastic tube, unreachable, seeming to block any access (this turned out to be the pump handle casing, doh!....tentatively added water and it works! Oh well, novice at this... but I'm learning. ;)
Jo, August 2014