The present invention relates to a reversible air-conditioning circuit (1) comprising: • a main loop (A) comprising a compressor (3) and a water condenser (5) jointly connected to an auxiliary circuit, a first expansion device (7), an external evaporator-condenser (9), a second expansion device (15), and an evaporator (17), • a first bypass branch (B) comprising an internal condenser (13), the first bypass branch (B) connecting a first junction point (31) arranged downstream from the water condenser (5) to a second junction point (32) arranged upstream from the second expansion device (15), • a second bypass branch (C) connecting a third junction point (33) arranged downstream from the external evaporator-condenser (9) to a fourth junction point (34) arranged downstream from the evaporator (17), and • a third bypass branch (D) connecting a fifth junction point (35) arranged downstream from the third junction point (33) to a sixth junction point (36) arranged downstream from the first junction point (31).