I have a problem with a slow filling WC which was working okay until recentely. On looking in the cistern, the inlet valve (side entry) appears to be a strange looking tower contraption which looks as though it should fill the cistern from within its internal gubbings. However it just seems to squirt slowly out of some sort of levered valve at the top. The inlet pipe is quite small (less than 15mm). Anyone know what this type of valve is called and can you get replacements? Apologies for being a bit long winded.