I had a similar problem a couple of weeks ago , I only partly filled the flush and although the pump sounded as though it was working no water came out , tried draining and starting again but nothing so tried filling the flush to the normal level and all worked fine , had a good read thru the Abbey handbook but couldnt find anything about having to put a full amount in the flush tank .Hi Davy
I went to my van last week and before I stripped down the pump switch etc., I tried the pump and to my surprise and delight the flush delivered water.
I summise that the flush water which I mix with the pink additive produces some "froth" whilst filling the flush tank,
causes a vacuum which the pump cannot handle. I have drained down the flush tank, then filled it with clean water, and then added the pink additive and now everything works fine.
Thanks for the advices
Regards
Sheila and her Hubby Fred