toilet cistern float valve faulty?

[tommyl18]

Ive got a brand new toilet and the float valve fills the cistern and stops as normal but it will randomly start filling for a couple of seconds at various times throughout the day there is no leaks anywhere and the water level is no where near the overflow. Could have been a coincidence but it did it when we turned the tap on down stairs and when we moved around or made any vibrations near it.

any ideas ?

 

[75pete]

Could be the wrong size fitting in your new loo. There are two sizes that can be fitted to the control valve, first and fitted as sandard is the low pressure fitting, the high pressure fitting should be found on the ballcock arm and can replace the low. Now, if your loo fills via the main and not the header tank, it could point to the wrong fitting and thus water passing and the loo over flowing.
pete

 

[tommyl18]

it has got a cork screw type plastic insert and it did also come with a rubber diaphragm in a bag but i presumed this was a spare

 

[denso13]

I had one similar to this. Turned out the washer between the syphon and cistern was passing, very slightly, and allowing water to leak into the WC bowl. Cistern would then fill in short burst when water was low enough.

The flow of water into the bowl was hardly noticeable. Maybe turn the water of to the cistern and see if the water level drops over a longer period?