The circulation pump of a heating system transports the water heated in the boiler to the radiators in the individual rooms of a building. Many of the circulation pumps in use today have a low efficiency and convert only 10 to 15 percent of their total electricity demand into mechanical power.

Modern speed-controlled circulation pumps are much more efficient and enable power savings of up to 50 percent. These pumps use efficient electric motors as well as optimised controls. Thanks to their variable speed, they easily adapt to changing system conditions and supply the amount of water that is actually needed. Going forward, pumps featuring permanent magnet motors will achieve even further improvements.

The Wuppertal-based "Institut für Klima, Umwelt und Energie" (Climate, Environment and Energy Institute) estimates that some 3 to 4 billion kilowatt hours of electricity could be saved per year in Germany alone if all existing circulation pumps in single-family and two-family houses were replaced with highly efficient pumps. This is more or less equivalent to the average annual power output of a medium-sized nuclear power
station.