Reheating method for operating a refrigeration system with a heat pump function for a motor vehicle, wherein the refrigeration system comprises: a refrigerant compressor which can be connected or is connected to a primary line and a secondary line; an external heat exchanger which is arranged in the primary line; an evaporator which is arranged in the primary line; a heating register which is arranged in the secondary line; at least one reheating expansion valve, which is arranged between the heating register and the external heat exchanger in the secondary line; wherein in the reheating method the refrigerant, starting from the refrigerant compressor flows through the following components in the refrigeration system one after another: heating register and reheating expansion valve in the secondary line, external heat exchanger and evaporator in the primary line, wherein the reheating method comprises the following steps: determining a heat differential value (Wdiff) by comparing a heat emission actual value (Wist) at the heating register to a heat emission target value (Wsoll), characterized by an adjusting of at least one operating setting of the refrigeration system, so that the load capacity in the refrigeration system is increased if the heat differential value (Wdiff) is greater than 0 and less than a heat differential threshold value (Wds), wherein the adjusting of the operating setting comprises: measuring the temperature of the supply air after flowing through the evaporator and reducing a target temperature (SP T_Verd) for the temperature of the supply air after flowing through the evaporator. a refrigerant compressor which can be connected or is connected to a primary line and a secondary line; an external heat exchanger which is arranged in the primary line; an evaporator which is arranged in the primary line; a heating register which is arranged in the secondary line; at least one reheating expansion valve, which is arranged between the heating register and the external heat exchanger in the secondary line; wherein in the reheating method the refrigerant, starting from the refrigerant compressor flows through the following components in the refrigeration system one after another: heating register and reheating expansion valve in the secondary line, external heat exchanger and evaporator in the primary line, wherein the reheating method comprises the following steps: determining a heat differential value (Wdiff) by comparing a heat emission actual value (Wist) at the heating register to a heat emission target value (Wsoll), characterized by an adjusting of at least one operating setting of the refrigeration system, so that the load capacity in the refrigeration system is increased if the heat differential value (Wdiff) is greater than 0 and less than a heat differential threshold value (Wds), wherein the adjusting of the operating setting comprises: measuring the temperature of the supply air after flowing through the evaporator and reducing a target temperature (SP T_Verd) for the temperature of the supply air after flowing through the evaporator. determining a heat differential value (Wdiff) by comparing a heat emission actual value (Wist) at the heating register to a heat emission target value (Wsoll), characterized by an adjusting of at least one operating setting of the refrigeration system, so that the load capacity in the refrigeration system is increased if the heat differential value (Wdiff) is greater than 0 and less than a heat differential threshold value (Wds), wherein the adjusting of the operating setting comprises: measuring the temperature of the supply air after flowing through the evaporator and reducing a target temperature (SP T_Verd) for the temperature of the supply air after flowing through the evaporator.