We bought our place 2 1/2 years ago. It's an old house (1924), but supposedly the piping was replaced with new copper piping (I don't know exactly when). When you get about 2 minutes into a shower the pipes will start vibrating loudly, will only stop if we turn down the water. This started just about a week ago. This doesn't happen with any other faucet or appliance. I know I'm going to have to call a plumber, just want to hear what people think the problem is (and how BIG a problem) before I do. It's makes our dog get VERY agitated. Any ideas? Thanks in advance...