Leaky built in Cistern

[Nintendofan]

I have a built in Roca toilet in a 4 year old new build that's leaking clean water into the pan very slowly, thus filling the cistern with water every hour or so for a few seconds. Can the flush valve be serviced/removed through the button panel or do the tiles need to com off? Thanks

 

[CountryFan]

It depends if you can get the cover plate off and if there’s enough room to get hands in to undo the bayonet style connection and pull it through.

 

[Nintendofan]

Ive taken the panel off and attached a picture, are they designed to be serviced through the hole or will I need access underneath therefore having to remove the tiles?

 

[opps]

I am not a plumber...

When my Gerber(?) concealed cistern started doing the same thing, I had to remove the flush plate and pull out the loo flush mechanism. Youtube helped a lot. I had to replace the washer at the very bottom of the mechanism. Fortunately, they had provided a spare washer in the back of the flush plate.

 

[CountryFan]

Ive taken the panel off and attached a picture, are they designed to be serviced through the hole or will I need access underneath therefore having to remove the tiles?
View attachment 380610

I think that blue plate will need to be removed, and then it may be possible to service it.