Have just had our first weekend away in our new (to us) 2016 Troll. All seemed good, except we have an irritating problem with the toilet flush that I can't solve.

When you flush, some of the water is finding its way out of the toilet assembly and coming out under the washroom "wall" and pooling on the floor opposite the door. Some flush water is also pooling in the bottom of the waste tank housing. Anyone ever had this and managed to solve it? I can take it back to the supplying dealer, but they are 190 miles away, so that's a last resort, really.

It could be the seal on the top of the waste tank, however that seems to be clean and flexible. And water getting out there would only get into the waste tank housing, I'd have thought. For water to get out of the toilet assembly there must be a break in the housing somewhere... I have found no one else suffering the same issues anywhere online, apart from a much older toilet assembly where they put a thin sheet of plastic under the waste tank to push the top seal more tightly against the seat "hole". The flush does seem very powerful, but it runs round the rim as it should. I wonder if the problem only occurs if the open/close flap is only partially open...

Any pointers are most welcome. I have half a tank of flush water onboard, so I am happy to experiment today to try and solve the problem.

The toilet is a Thetford bench-type C402C

Looking again just now (to photograph it) I can see the toilet assembly is not sealed - it is open into the caravan interior at the external wall and, I think, the interior too.

Cheers, Simon

I have ordered a new seal for the top of the waste tank. Seems the likeliest option for a leak point...

As you say, if water is evident on the caravan floor around the toilet it suggest a leak that isn't at the mating point between cassette and bowl. Leaks at that point will flow over the top of the cassette and onto the floor of the cassette space.

I have heard of leaks between flush tank and bowl outlet but they're a devil to access in a swivel Thetford, not sure about the bench type access. The rubber seal on the cassette does go hard and need replacement so that's worth doing at 9 years old anyway.

We had a new C250 in a new Adria motorhome in 2008 that had plastic shims under the cassette to keep it engaged. We assumed they'd made the cassette space slightly too large and it was corrected in later production.

The C402 has been around for a long time so I doubt it has a similar problem.

I'll try the new seal and then, if it still leaks, I'll try shimming it to narrow the gap. Trial and error I expect. Our 2005 Triton had the same bench-style toilet (before Eriba experimented with the swivel-type for a few years) and that didn't leak its flush water after 20 years (although it may have had its seal replaced before we bought it)...