An air conditioning system includes: outdoor and indoor heat exchangers; first, second, and third control valves, which block refrigerant flow when fully closed; and a pressure adjuster. The first and second control valves are disposed in a gas-side refrigerant flow path (GL) between the outdoor and indoor heat exchangers. The third control valve is disposed in a liquid-side refrigerant flow path (LL) between the outdoor and indoor heat exchangers. The pressure adjuster adjusts the pressure of refrigerant in an indoor-side refrigerant flow path (IL) between the first control valve and the second control valve or the third control valve and the indoor heat exchanger. The pressure adjuster includes a pressure adjusting valve that bypasses refrigerant in the indoor-side refrigerant flow path (IL) to an outdoor-side refrigerant flow path (OL) between the first control valve and the second control valve or the third control valve and the outdoor heat exchanger.