Refrigeration circuit (1, 1′) for circulating a refrigerant in a predetermined flow direction through at least one functionally disconnectable component, the refrigeration circuit having in flow direction an expansion device (b, b′, 26, 26′, 33), an evaporator, a compressor (2, 2′, 29, 36) and a heat-rejecting heat exchanger (6, 20), wherein an upstream-side shut-off valve is provided upstream of the component and a downstream-side shut-off valve is provided downstream of the component, wherein at least one of these shut-off valves is a non-return valve (a, c, 25, 27, 32, 34). Preferably, the component has in flow direction the expansion device (b, b′, 26, 26′, 33) and the evaporator (12, 12′, E1, E1′, E2) or the compressor (2, 2′). Preferably the non-return valve (a, c, 25, 27, 32, 34) is lockable in it's open position.