After installing all system components, it is recommended to perform pressure tests and leakage tests to ensure that there are no leakages in connections of all system components. It is recommended to use a water test when using the water for the cycle, and ensure that there is no leakage under a water test pressure of 6 bar. It is recommended to use a nitrogen gas test when using the coolant for the cycle and use a soap bubble method to test sealing positions of connectors, and ensure that there is no leakage under a gas test pressure of 4 bar. If an air compressor is used for the gas test, there is a risk of condensation in the air, which may cause the water to mix into the cycle system. There are risks in directly injecting the coolant for the pressure test. Once the leakage occurs, it is difficult to collect the coolant.