What impact does a TXV stuck nearly shut have on a refrigeration system?

When a thermal expansion valve (TXV) is stuck nearly shut, it significantly restricts the flow of refrigerant into the evaporator coil. This reduction in refrigerant flow directly affects the pressure within the suction line.

Specifically, the limited refrigerant entering the evaporator results in insufficient absorption of heat from the indoor air. The evaporator cannot maintain the necessary temperature and pressure, leading to a decrease in the overall efficiency of the cooling process. Consequently, the reduced refrigerant flow causes the suction pressure to drop, potentially leading to low suction pressure readings on the system's gauges.

This condition can cause various operational issues for the refrigeration system, including increased compressor cycling and the risk of compressor damage due to low refrigerant conditions. Thus, recognizing that a TXV stuck nearly shut leads to low suction pressure is crucial for diagnosing and addressing malfunctioning refrigerant flow in a residential air conditioning system.