Water Hammer

Chief of

Hi all. I had a problem with the downstairs toilet. Had to change the valve. As the shut off valve wasn't stopping the water and it was going into the overflow, and trickling into the bowl(Bottom entry, vertical type).
Since then the pipes have been banging like mad. The tank is above my bedroom and it's driving me mental. I drained the tank in the attic and filled it again to reintroduce air for cushioning. That worked for a few days but the banging is back. If I leave the cold tap on in the ensuite the banging stops but obviously can't leave it like that.
Here's hoping someone out there can help. Sorry for the long-winded spiel.
Thanks

cerastes

Maybe something isn't seated right, I'd an issue with a toilet not filling fast enough, I dissasembled the fitting, cleaned away some debris and put it back together, then started getting the banging you are mentioning. I took it apart again and in my case I think the part that impinges on the seal wasn't fitting right, can't recall exactly now but it was something not seated right. Not sure what you mean by draining the tank to reintroduce air to cushion?

Chief of

Thanks for the reply. It was the ball cock in the tank. The valve wasn't closing properly and the arm off the ballcock was vibrating and hitting off the side of the tank and this was vibrating down through a pipe in the wall.