creditchris It’s most likely to be the vacuum breaker
I made an annotated diagram for you
Just replace the vacuum breaker and use water with less calcium in. I can’t remember if it can be removed and cleaned inside easily…but you could give that a try. When removing clean the threads well and put back using 7-9 wraps of PTFE tape, so it feels tightish all the way in, but don’t snug it down, stop close to the bottom when at the right angle.
