Noise what water off

[AliBerman]

How to stop/cure the high pitched noise bathroom sink that stops when water turned on but then starts again shortly ( time varies ) after water has been turned off. Do not know if relevant but I noticed if I turn on the cold water only, there is first a entirely different lower like noise for a while.

 

[Deleted member 120897]

Do you have a hot water cylinder? Could be the float valve if yes.