I have just fitted a new toilet (with p-trap) which backs up to a furniture unit containing a hidden cistern. It is next to a matching sink unit. The depth of the unit is about 220mm. I have connected the P-trap exit to the cast iron pipe in the wall with a pipe. I have actually used one of those concertina pipes. Anyway the new toilet doesn't flush very well and I'm concerned that this is because the waste now has to travel along a short horizontal pipe length before dropping down the "shute". Have I made a design error, or shall I just replace the concertina pipe with a rigid pipe and maybe fill the cistern a bit more ?
ps the previous loo connected directly to the cast iron pipe and was trouble free.
ps the previous loo connected directly to the cast iron pipe and was trouble free.