SOS – Just moved into a new house and didn’t notice serious pipe banging in our main shower till after we moved in. We have a single adjustment knob to adjust the hot/cold water. This water banging only occurs when the knob is pulled all the way out and setting is exactly in between the hot and cold setting. I’ve traced the lines for signs of trapped air, secured some pipes in basement that weren’t secured properly and have had the cover plate off behind the adjustment knob to adjust hot/cold water inlet/outlet valves. PLEASE SOS – have visions of ripping out the wall to correct problem.