What happens to the solenoid valve when the system enters defrost mode?

In defrost mode, the primary goal is to melt any frost or ice that may have accumulated on the evaporator coil. To achieve this, the solenoid valve plays a crucial role. When the system enters defrost mode, the solenoid valve closes. This action effectively stops the flow of refrigerant to the evaporator coil, allowing the heating elements to activate. By stopping the refrigerant flow, the evaporator coil can warm up, which facilitates the melting of frost or ice, thereby maintaining the efficiency and effectiveness of the refrigeration system.

This process differentiates it from other modes, where refrigerant flow is typically necessary for cooling. In defrost mode, closing the solenoid valve is essential for the proper functioning of the defrost cycle and serves to protect the system from damage that could occur if frost were allowed to build up excessively.