A service water heating unit (2) provided for use in a heating installation includes at least one heat exchanger (6), having a first flow path (10) in which a heating medium flows and a second flow path (12) in which service water to be heated flows, and a first circulation pump (46) which pumps the heating medium. The first circulation pump (46) is connected to the first flow path (10) of the heat exchanger (6) and mounted onto the heat exchanger (6). The service water heating unit (2) can also include a second circulation pump (76) mounted to on the heat exchanger (6), that pumps the heated service water.