De Dietrich 7641852 circulation pump RS 15/65R 130 3H

This is a De Dietrich circulation pump, listed under catalogue article 511.532.001 and manufacturer code 7641852. Parts of this type are installed in the heating circuit to move heated water from the boiler or heat exchanger through the radiators, underfloor loops or other heat emitters, and back to the return. In a typical boiler system the pump operates after the heat exchanger has transferred energy to the water; it ensures a steady flow rate and helps maintain the temperature differential across the system. When selecting a circulation pump of this class, the key parameters are the required head (pressure) and flow rate for the specific installation, the port spacing (centre-to-centre distance of the connections), the connection size and type (usually threaded or flanged), and the control mode – fixed speed versions run constantly at one setting, while electronically regulated models adjust speed to match heat demand. The union or flange pattern must match the existing pipework or pump group manifold. Common issues to check during replacement include a seized rotor after a long standstill period, often caused by debris or calcification; air trapped in the pump head, which can block flow and cause noise; and on high‑efficiency models, failure of the built‑in electronics or motor module. Always verify the port spacing and connection size before fitting a replacement pump of this type.