Guys, How do these bottle air vents work? Tried to search on the web and can find nothing. I have just bought one and when I shake it something solid rattles inside. I am replacing the one that is seized up and sits at the top of a piece of pipe in my airing cupboard. Does the rattling bit press against something internally when full of water?
It has 3/8 connection and a sort of twist valve at the top (like the top of a biro pen). Should that twist valve bit be screwed tight or loose?
Thanks, Steve