What are signs indicating a malfunctioning expansion valve?

Inconsistent cooling and high superheat are key indicators of a malfunctioning expansion valve. The expansion valve plays a critical role in regulating the flow of refrigerant into the evaporator coil. When the valve is malfunctioning, it may not open or close properly, leading to inconsistent cooling. This inconsistency can manifest as variations in temperature within the refrigerated space, often due to insufficient refrigerant flow to the evaporator.

High superheat occurs when the refrigerant vaporizes completely before it reaches the expansion valve, leading to elevated temperatures that can cause compressor damage over time. Superheat is considered high when the refrigerant is in a vapor state and has absorbed excess heat, which can indicate that the evaporator is not receiving enough refrigerant to function effectively. Therefore, recognizing these signs is crucial for diagnosing issues with the refrigeration system and ensuring it operates efficiently.