What is a common symptom of a plugged filter drier?

A plugged filter drier can significantly affect the operation of a refrigeration or air conditioning system, commonly resulting in high head pressure. The filter drier serves to remove moisture and contaminants from the refrigerant, which is essential for maintaining the overall health of the system. When the filter drier is obstructed or plugged, it creates a restriction in the refrigerant flow.

As a consequence of this restriction, the refrigerant cannot circulate efficiently, leading to an increase in pressure on the discharge side of the compressor, hence the term "high head pressure." This elevated pressure can cause mechanical strain on the compressor and reduce the efficiency of the cooling process, possibly leading to overheating and eventual system failure.

The other symptoms, such as low system pressure, frost formation on the evaporator, and increased compressor cycling, could also be indications of various other issues in the system or might occur under different situations. However, high head pressure is a direct result of the improper flow caused by a plugged filter drier, making it the most common and relevant symptom in this scenario. Understanding these effects is crucial for diagnosing and maintaining residential air conditioning systems effectively.