Hi, when we turn the HOT tap on in the kitchen we get a knocking upstairs in the bathroom, but if I turn the basin hot tap or shower on it stops? We've got a combination type boiler. If I leave either the basin tap on or the shower on for a while, 2/3 minutes, its stops knocking for the first time used, but then it returns after a while? The shower works of the combination boiler by the way.
Cheers4now Fogogof.