How does recirculation work?
Tankless water heating recirculation works when a pump is activated by a switch or motion sensor. This is the most energy- and water-efficient way to operate a tankless water heater. It is also offers the most cost saving. Here’s how it works:
1. A switch or motion sensor located near each fixture (such as a shower or appliance) activates an energy-efficient circulation pump.
2. The circulation pump houses a temperature sensor and a check valve that prevents water from entering the return line. The pump moves ambient-temperature water sitting in the line back to the tankless water heater. The sensor lets the pump know when hot water has arrived at the farthest tap and shuts off the pump so energy isn’t wasted.
To learn more, check out an article by Rob Yagid in Fine Homebuilding Magazine, titled “Hot Water Recirculation Systems: How They Work.”