Toilet leaking and refilling

[Ben-gee]

Does it still do it when the lid is off the cistern?

If not then the button is probably pushing down and holding the valve partially open, adjust the height of the valve downwards or shorten the rods from the button.

If it does do it with lid off ignore the above!

 

[rpm]

Does it still do it when the lid is off the cistern?

If not then the button is probably pushing down and holding the valve partially open, adjust the height of the valve downwards or shorten the rods from the button.

If it does do it with lid off ignore the above!

Good point if a recent install, always worth checking out though.

 

[Warmiger]

Looking at your photo it looks like one of the ideal standard flush valves.
As mentioned take a look at the rubber washer for limescale. If need be replace it sometimes the rubber blisters and no longer holds. The flush valve should remove with a quarter turn.
The push button is not adjustable on these as it has a big plastic flat piece on it rather than rods.
With the cistern lid off just make sure the inlet valve isn’t constantly running and water is going down the internal overflow.