I'm getting alot of noise in my water pipes. It tends to happen when I have the power shower on but can also happen when I run the cold water tap in the bathroom. I don't get the thud noise when I turn the taps off so I have sort of discounted water hammer. I have turned the pressure down at the stop cock and still the same problem. All the pipe brackets check out ok. It is air in the pipes but i'm running out of ideas on how to stop the problem. I have tried ; opening up the cold taps turning off the stop cock running the taps out close the taps off turn the stop cock on turn the taps on Seems to sort out the problem for a bit then I get the noise back again? I've asked loads of plumbers Anyone got any other possible solutions? Thanks.