Hi there
First question on here
I fear we have a leak in the inner works of the toilet cistern/tank, the floating ball and outlet valve all seem correct, I'm guessing there is an issue with one of the seals, when the tanks emptied I can't see any visible dripping, overnight the water level rises about an inch.
Is there several washers that could need replacing, an obvious weak spot rather than replace the whole internals?
Reducing the height of the overflow is a temp fix but obviously won't help with the leak
Thanks in advance

Welcome to The Plumbing Page at AMHD.com.

I'm guessing there is an issue with one of the seals, I can't see any visible dripping, overnight the water level rises about an inch.
Sure sounds like a bad flapper to me. Replace the flapper and see if that doesn't solve the issue. Good luck Tom

I see this differently. Sounds like the water is rising and running into the overflow? If so, you have a fill valve in need of repair or replacement. Im betting Tom can give you pics for you to choose which is yours. In all honesty, replacing the complete fill valve (cheap and normally easy) will give you the best result.