A circulator pump is used to keep the domestic hot water circulating back to the production system (heat exchanger or water heating unit).
Circulation of domestic hot water ensures a flow inside the pipes, even though hot water is not withdrawn. In this way, the waiting time is kept to an acceptable level. The domestic hot water is circulated at a given minimum temperature to minimise energy consumption. This is controlled by a circulation valve, strategically placed several places in the domestic hot water system.