# Can I Do This Electrical Thing-Water Heater Recirculating Pump **URL:** \ **Category:** Factual Questions\ **Created:** [November 30, 2022, 8:44pm UTC](https://boards.straightdope.com/t/can-i-do-this-electrical-thing-water-heater-recirculating-pump/975821 "2022-11-30T20:44:47Z")\ **Posts on this page:** 1\ **Showing post:** 13
**Author:** ![Lare](https://avatars.discourse-cdn.com/v4/letter/l/53a042/32.png) [@Lare](https://boards.straightdope.com/u/Lare)\ **Post date:** [December 1, 2022, 5:13am UTC](https://boards.straightdope.com/t/can-i-do-this-electrical-thing-water-heater-recirculating-pump/975821/13 "2022-12-01T05:13:34Z")
There is a special device that hooks to the hot and cold taps at the farthest faucet. Inside that is a temperature-sensitive device that is open when the water on both sides of it are cold. On demand, or on a timer, the recirculating pump sends hot water through the hot water line, to this valve, and then forces it back on the cold water line. It does this until the temperature valve senses that hot water is now available at the faucet. At this point the valve closes, leaving hot water at the hot faucet. There’s a lengthy writeup here: > **[How Does Hot Water Recirculation Pump Work? #Diagram - Water Browser](https://waterbrowser.com/how-does-hot-water-recirculation-pump-work-diagram/)** > > Contents1 What Purpose Does a Recirculation Pump Serve?2 What is the Main Cause of Slow Hot Water?3 How Does a Hot Water Recirculating Pump Work?4 What Is the Sensor Valve?5 How Does An “Under Sink” Hot Water Circulating Pump Work?6 How Does A... The loop is completed by the temperature-sensitive valve at the farthest end from the heater. This goes under the sink at the faucet connections. You could probably do this as you don’t need into-the-concrete access. Here’s the manufacturer page: [https://www.watts.com/products/plumbing-flow-control-solutions/water-heater-accessories/hot-water-recirculating-systems#](https://www.watts.com/products/plumbing-flow-control-solutions/water-heater-accessories/hot-water-recirculating-systems#) --- _[View the full topic](https://boards.straightdope.com/t/can-i-do-this-electrical-thing-water-heater-recirculating-pump/975821)._