I remember seeing Richard installing a vale in a bathroom of a homeowner where it took several minutes to get hot water to the master shower. My wife and I have that same problem. Our master bath is a long way from the water heater. It did not require any additional piping, but used the existing piping. It recirculated the hot water somehow. Not sure exactly how it worked. If anyone knows about this valve, I would appreciate that info. Thanks in advance.