Hello, I had this problem is my bedroom, where there was a rattling in the wall. It turned out it was something to do with water in the pipe, so I turned the water off at the valve, turned all taps on to drain the water out, that problem solved. The other problem now is that I get water hammer, that loud bang, when I flush the toilet. Turning the water off and flushing the toilet solves the problem, but then it comes back maybe two weeks later, and I have to repeat the process. Is it okay for me to do this or will it damage the pipes?