Heat pump apparatus and method of controlling heat pump apparatus

A heat pump apparatus comprising:

• a first refrigerant circuit through which a refrigerant is circulated, the first refrigerant circuit including a first compressor, a first heat source heat exchanger, a first expansion mechanism, and a first intermediate heat exchanger sequentially connected in loop by pipes;
• a fluid circuit through which a fluid is circulated, the fluid circuit including the first intermediate heat exchanger, a first valve, a load heat exchanger, and a second valve sequentially connected in loop by pipes;
• a leakage detecting device that detects leakage of the refrigerant, circulated through the first refrigerant circuit, from the first intermediate heat exchanger into the fluid circuit;
• and
• a controller that closes the first valve and the second valve included in the fluid circuit when the leakage detecting device detects the leakage of the refrigerant, wherein the leakage detecting device detects the leakage of refrigerant by detecting pressure within the fluid circuit.