I have a push button, dual flush toilet. Lately, when the cistern is filling, it does not do so in one go. It stops and starts about three times till it reaches the required level. This only takes a few seconds. There is no water escaping into the pan, so I think that it is working normally apart from the sporadic filling.I think that it is a Fluidmaster.
Hi greenveg Suggest you try taking the valve apart and washing everything in clean water. If this fails replace the whole thing but don’t expect it to be a doddle. Regards S