My toilet isn't flushing properly, the pan fills almost to the top before gradually returning to its normal level.
Examining the toilet and the waste pipe coming from the toilet it doesn't appear to be blocked. We live in a bungalow and the bathroom is extended. As a result the the vertical pipe that comes from the waste pipe is inside. When I remove it, the flush seems to work normally, as if it is something to do with pressure.
Flushing really has nothing to do with preasure in a standard application. It works off of the wieght of the flushing water, a bit of siphoning, and the drain pipe has to run down hill enough to keep a steady rapid flow. If the down grade of the drain isn't enough it will cause this type of problem.