The Sunbank Recirculation Valve and Pump Kit uses the Watts (Grundfos) valve that connects the hot and cold supply lines under the sink in the bathroom furthest from the water heater, allowing for the cold water line to be used as a recirculation line for hot water. This was designed to allow for instant hot water at the tap which can save a lot of water instead of waiting for hot water to arrive at the tap. It can be used with a timer, a motion sensor, or any other smart speaker or device.
The Sunbank Recirculation Valve and Pump Kit works with the T/P valve to protect the system from overheating (although more effective overheating when paired with a radiator or other heat dump), protects the piping from freezing, saves water, and saves money. Although it is not necessary for all installations, the Sunbank Recirculation Valve and Pump Kit is a good addition to most installations and like the Sunbank Solar Water Heater, it pays for itself quickly.