Push button toilet overflowing

[cairns]

Hi, I had a top fitted push button toilet fitted two years ago.It has started to overflow due to the the stop valve not working and the water in the cistern is pouring down the central overflow.The water stops flowing in when I lift the valve arm.
I will be calling my plumber on Tuesday for some other work and will get him to look at it but is there a simple way to check the input valve for grit etc?
My bathroom fitter removed all the documents about the flushing system so i cant even tell what make it is.
Many thanks.

 

[KingDoey]

If the water stops flowing when you lift the float then just adjust it and make it lower

 

[WaterTight]

Well, no, that's not the answer. If it wasn't overflowing before and now it is you need to either change the washer/seat in the float valve or change the float valve. You may well be able to force it shut by pulling the arm up but that's not a permanent solution.

 

[Mikey456]

Sounds like the washers gone, replace the diaphragm and orifice

 

[cairns]

Many thanks for the replies.I have managed to free the valve controlling water inflow and water has stopped poring into wc.Plumber will check it on Tuesday.
Your help is appreciated.