A method for operating a vapour compression system (1) comprising a heat recovery heat exchanger (4) is disclosed. The heat recovery system requests a required level of recovered heat to be provided by the heat recovery heat exchanger (4) to the heat recovery system, generates a signal indicating the required level of recovered heat, and supplies the generated signal to a control unit of the vapour compression system (1). A setpoint value for at least one control parameter of the vapour compression system (1) is calculated, based on the generated signal, and the vapour compression system (1) is operated in accordance with the calculated setpoint value(s).