AquaMotion’s AquaMotionHot recirculation systems deliver instant or user-controlled hot water whenever needed. The “R” series installs under a sink or on a dedicated return line to work with on-demand tankless water heaters and standard water heater tanks. This larger size pump is a three- speed circulator and creates enough flow to activate the tankless water heater and start the circulation of hot water throughout the house. Hot water recirculation systems increase comfort while saving up to 15,000 gal. of water per year, the company stated.