thetford c2/3 toilet flush

Hi all, I have a slight problem with the toilet flush system as far as I can see it draws water from the main tank, but depressing the flush button the pump is not activated, but if opening any tap the pump switches on, I have checked the 3 amp fuse inside the cassette that is ok there is also a electrically operated valve which allows water into the toilet that is also working but still no flush, any ideas please
many thank in advance
mike 
vwt4

I may be entirely wrong, but I don't recall that the flush was drawn from the main tank in an early Trophy I owned. It was drawn from a tank integral to the toilet body, and had to be filled regularly.  If you have owned your Trophy for long enough, you will know whether this applies to your vehicle. Keith

Hi. Yes it is drawn from main  tank, but pressing  the flush button the pump is not activating, just wondered if any one had any idea where to look for the problem
Mike
VWT 4

<sorry - didn't read the OP properly!>

Pump is activated by a drop in pressure. If the electronic valve is working correctly it's either a blockage in the pipe or the pipe is kinked or trapped. I would try taking the feed pipe off the valve with the pump switched off, put the pipe into a bucket and then switch the pump on to see if there's any flow...work back from there!

many thanks to all for suggestions
mike
vwt4