Refrigeration and heating system comprising a refrigeration circuit which comprises in the direction of flow of a circulating refrigerant: at least one compressor (6a, 6b, 6c); a refrigeration circuit side of a coupling heat exchanger; at least one gas cooler; at least one gas cooler bypass line and at least one gas cooler bypass valve assembly allowing to bypass the at least one gas cooler; at least one high pressure expansion device; and at least one evaporator; and a heating circuit which comprises in the direction of flow of a circulating heating fluid: a heating circuit side of the coupling heat exchanger; and at least one heating device; wherein the coupling heat exchanger is configured for transferring heat from the circulating refrigerant to the circulating heating fluid; and wherein the gas cooler bypass valve assembly is configured for allowing to selectively direct a first flow of refrigerant either through the gas cooler or through the gas cooler bypass line bypassing the gas cooler and for gradually or continuously regulating a second flow of refrigerant flowing through the other of the gas cooler and the gas cooler bypass line which mixes with the first flow downstream of the gas cooler characterized in that the gas cooler bypass valve assembly comprises a digital three-way gas cooler bypass valve, which allows fluidly connecting the inlet side of the high pressure expansion device either to the outlet side of the gas cooler or to the gas-cooler bypass line, without providing any mixing functionality; and adjustable bypass valve allowing to by-pass the digital three-way gas cooler bypass valve. a refrigeration circuit which comprises in the direction of flow of a circulating refrigerant: at least one compressor (6a, 6b, 6c); a refrigeration circuit side of a coupling heat exchanger; at least one gas cooler; at least one gas cooler bypass line and at least one gas cooler bypass valve assembly allowing to bypass the at least one gas cooler; at least one high pressure expansion device; and at least one evaporator; and a heating circuit which comprises in the direction of flow of a circulating heating fluid: a heating circuit side of the coupling heat exchanger; and at least one heating device; at least one compressor (6a, 6b, 6c); a refrigeration circuit side of a coupling heat exchanger; at least one gas cooler; at least one gas cooler bypass line and at least one gas cooler bypass valve assembly allowing to bypass the at least one gas cooler; at least one high pressure expansion device; and at least one evaporator; and a heating circuit which comprises in the direction of flow of a circulating heating fluid: a heating circuit side of the coupling heat exchanger; and at least one heating device; a heating circuit side of the coupling heat exchanger; and at least one heating device; wherein the coupling heat exchanger is configured for transferring heat from the circulating refrigerant to the circulating heating fluid; and wherein the gas cooler bypass valve assembly is configured for allowing to selectively direct a first flow of refrigerant either through the gas cooler or through the gas cooler bypass line bypassing the gas cooler and for gradually or continuously regulating a second flow of refrigerant flowing through the other of the gas cooler and the gas cooler bypass line which mixes with the first flow downstream of the gas cooler characterized in that the gas cooler bypass valve assembly comprises a digital three-way gas cooler bypass valve, which allows fluidly connecting the inlet side of the high pressure expansion device either to the outlet side of the gas cooler or to the gas-cooler bypass line, without providing any mixing functionality; and adjustable bypass valve allowing to by-pass the digital three-way gas cooler bypass valve.