Hi. Our toilet often does not flush. I am quite certain it needs a new siphon or diaphragm. I am very tempted to have a go at doing it myself but am put off by reading that I may have to remove the cistern from the wall & it all sounds a bit tricky. It is a close-coupled unit. Can anyone advise me whether the job is straight forward or would I be better off getting a plumber in to do it.