A high-voltage self-blast circuit breaker, comprising: an enclosure filled with an interrupting and insulation medium; a contact arrangement held in said enclosure, having first and second contact members being movable relative to each other along an axis (A) during a switching operation, the first contact member comprising a first arcing contact , the second contact member comprising a second arcing contact , the first and second arcing contacts defining an arcing zone therebetween, the first contact member further comprising a heating volume and a nozzle defining a heating channel between the heating volume and the arcing zone; a secondary compression volume configured for being expanded during an opening operation of the high-voltage circuit breaker, and for being compressed during a closing operation of the high-voltage circuit breaker; characterised by an inlet check valve arranged between an enclosure volume within the enclosure and the secondary compression volume for allowing a forward flow of the interrupting and insulation medium from the enclosure volume through the inlet check valve into the secondary compression volume during the opening operation of the high-voltage circuit breaker, and for blocking a reverse flow from the secondary compression volume into the enclosure volume during the closing operation of the high-voltage circuit breaker; an outlet check valve arranged between the secondary compression volume and the heating volume for allowing a forward flow of the interrupting and insulation medium from the secondary compression volume through the outlet check valve into the heating volume during the closing operation of the high-voltage circuit breaker, and for blocking a reverse flow from the heating volume into the secondary compression volume during the opening operation of the high-voltage circuit breaker. an enclosure filled with an interrupting and insulation medium; a contact arrangement held in said enclosure, having first and second contact members being movable relative to each other along an axis (A) during a switching operation, the first contact member comprising a first arcing contact , the second contact member comprising a second arcing contact , the first and second arcing contacts defining an arcing zone therebetween, the first contact member further comprising a heating volume and a nozzle defining a heating channel between the heating volume and the arcing zone; a secondary compression volume configured for being expanded during an opening operation of the high-voltage circuit breaker, and for being compressed during a closing operation of the high-voltage circuit breaker; characterised by an inlet check valve arranged between an enclosure volume within the enclosure and the secondary compression volume for allowing a forward flow of the interrupting and insulation medium from the enclosure volume through the inlet check valve into the secondary compression volume during the opening operation of the high-voltage circuit breaker, and for blocking a reverse flow from the secondary compression volume into the enclosure volume during the closing operation of the high-voltage circuit breaker; an outlet check valve arranged between the secondary compression volume and the heating volume for allowing a forward flow of the interrupting and insulation medium from the secondary compression volume through the outlet check valve into the heating volume during the closing operation of the high-voltage circuit breaker, and for blocking a reverse flow from the heating volume into the secondary compression volume during the opening operation of the high-voltage circuit breaker. <EOS>