A heat exchanger unit is utilized for heating service water in a heating installation. The unit includes a plate heat exchanger a first connector, attached to a first fluid connection point of the heat exchanger, and a second connector, fastened to the heat exchanger. The first and second connectors each include at least one base element. The base element of the first connector and the base element of the second connector have an identical configuration. Each base element includes at least two distinct flow ducts.