I’d read an article about an efficient hot water recirculation pump that was very efficient. It used about 5 W and had smarts that anticipated when the household demands hot water. I installed it in our newly constructed home, and was delighted with the instant hot water! After I installed Sense I noticed that our hot water energy usage was higher than expected. By eliminating the hot water recirculation I was able to halve the energy we were using for water heating. The water heater dropped from around 15% to 7% of our total energy usage!