I have a low level toilet cistern, which has never been any bother until
just the other day. For some strange reason the level within the cistern is
now rising too high and makes an exit out of the overflow pipe, which
unfortunately is leaking from a small joint.
What is likely to be causing the water to be rising about an 2 centimetres
higher than it ever did before. And if I could manage to stem the leak from
this overflow pipe with some tcp tape, should I not worry about the water
level?

Thanks in advance
douglas