The unit has a valve housing (2) that comprises an inlet (5) for a fluid flow and a heat exchanger outlet (11). The valve housing comprises a bypass outlet (12), where the fluid flow is guided at a heat exchanger through the bypass outlet based on a position of a valve disk (26). The valve disk is rotatably accommodated in the valve housing and the valve disk is rotatable between two positions. Independent claims are also included for the following: (1) an exhaust gas recirculation system with an internal combustion engine (2) an exhaust gas heat exchanger with a valve unit.
