Can an air lock cause a toilet cistern to over fill?

[fallops]

I have a fairly modern toilet and cistern, bought from B&Q a year or so ago.

After a while it began to continue over-filling after it had been flushed and over flow into the toilet pan.

More recently using other water sources in the house, eg bathroom sink, kitchen sink or even the washing maching filling with cold water can suddenly cause the toilet cistern to start filling again and then over flow.

If you lift the float part (i think it is a fluid master style button float) of it it stops for the time you hold it up, but as soon as you release it the water continues to flow. If you rattle or pump the float up and down quickly and then lift it, the water flow then stops.

Does anyone have any ideas of the cause or a solution? I was thinking that it might be a from an air lock or something as it is often caused by water running in a completely different part of the air supply!

Any help is great as it is driving us mad!

 

[ColJack]

worn valve..?
try adjusting the float rod.. there may be a screw to adjust it down a bit ( so the float holds the valve shut tighter, the same that you do when lifting the float )
failing that, if there's always the "bend it a bit" approach, bend the rod a bit.. simple..

 

[fallops]

I guess I didn't describe very well, this is the type of inlet!

 

[gaspro1981]

that fill valve is cheap and nasty tat throw it in the bin it and replace with a bottom entry dudley hydroflow
its not worth the hassle of trying to repair it