hj
Master Plumber
- Messages
- 33,613
- Reaction score
- 1,053
- Points
- 113
- Location
- Cave Creek, Arizona
- Website
- www.terrylove.com
Water is lazy, and it will flow the direction of least resistance. Without a check valve the direct line to its connection point, usually the furthest shower or tub, is MUCH more direct than the normal hot water path, so when you turn on THAT faucet the lazy water decides to flow through the recirculation line to get there. The initial water is hot, but soon the replacement cold water starts to flow through that same line. When you open MORE faucets at the end , the greater demand overwhelms the smaller circulation line and hot water starts flowing the right way. This ALWAYS happens, unless there is a check valve to prevent water from flowing through the circulation line, which is why I said, "it MUST have a check valve".