Explain the sensor valve operation

The sensor cross-over valve that you install under the sink at the furthest point in the branch will allow the cooled off 'hot' water in the hot water lines to be pushed back to the tank through the cold water lines until the sensor valve stops the cross-over action. Some of the water now in the cold water line will be warmer but will dissipate with just a few seconds of water flow. I find it a better trade off than the several minutes of wasting water that I used to have to do to wait for hot water. No other valves need be installed on either line other than the cross-over sensor under the sink(s). Additional cross-over valves can be added at the end of each branch line. I have one on my wife's vanity sink which covers her sink, my sink, the shower and tub in the master bath; one on the far sink in the guest bath which covers both vanity sinks and the shower, and one under the kitchen sink which covers the sink, dishwasher and power room.

It warms the cold water line but when you want cold water it is tepid for only a couple of seconds....for our installation anyway.

Hi, the cold water line is used as the return line for the hot water going back to the water heater. Water from the hot line is by-passed into the cold line until the temperature of HW at the sensor valve reaches 98?F at which point the sensor valve closes. No check valve is necessary. Please let us know if you have any other questions or concerns. Thank you.