I recently added a separate shower and his and hers sinks in my bathroom. When turning off the hot water at the sink, I hear a banging noise in the pipes. When the shower is turned on half way (90 degrees) I get a machine gun pulsating water spray with the banging noise. If turned on slowly it does not happen. Same with the faucet. Once in a while the faucet will make the shower pulse if the shower is in that same 90 degree position (warm but not hot water) and turned on quickly. Any suggestions? They are new fixtures.
Sounds like you have a loose washer some place in the line if it comes from both at the same time , have you got a valve in the main hw line, you sure it comes from sh. too, usually it is lav. faucet and also maybe you have not any air chambers int he line.