When a WC doesn't work properly, the problem usually lies in the cistern, not the pan. Fixing WC problems is straightforward, even if you have no plumbing know-how - as long as you understand how the flushing mechanism works. You just need a few basic tools and some inexpensive spare parts. Even getting access to the problem area is easy, just lift off the cistern lid. Cisterns in the loft can have problems, too - usually too much noise or a dripping overflow pipe.