What could lead to a malfunctioning thermal expansion valve?

A malfunctioning thermal expansion valve (TXV) is often influenced by temperature fluctuations in the refrigeration system. The TXV's primary function is to regulate the flow of refrigerant into the evaporator based on the temperature and pressure of the refrigerant entering. If there are significant temperature fluctuations within the system, this can disrupt the delicate balance that the TXV relies on to make accurate adjustments.

For example, if the evaporator temperature rises unexpectedly, the TXV may fail to respond appropriately, resulting in either too much or too little refrigerant being allowed into the evaporator. This can lead to inefficient cooling, insufficient evaporator operation, or even compressor damage due to slugging from liquid refrigerant.

In contrast, normal refrigerant flow and a perfectly sealed system would not inherently lead to malfunctions. While a high refrigerant charge can cause issues, it does not directly tie to the operational stability of the thermal expansion valve as temperature fluctuations do. Thus, fluctuations in temperature are a critical factor that can compromise the proper functioning of the TXV.