My mascarator is flushing it all away, liquids and solids no problem (there have been a million problems at different times, I know the inside of that toilet better than I know the back of my hand) but what is happening this time is that the liquid is coming back. After a while there is a bubbling and a gurgling and the next thing you know the bowl is half full of.... well, nasty water. I have worked out that if you don't leave anything at all in the bowl (water/pee etc) it is much less likely to do it. Is it the one way valve maybe? The boat is on the move over the next few days without me and once I get to my new home I will have to strip it down yet again and have a good look. But does anyone have any ideas? I love my mascerator until it all hits the fan. cheers.