Which of the following is not a symptom of a hermetic system low on refrigerant?

High head pressure is not a symptom of a hermetic system that is low on refrigerant. In fact, a low refrigerant condition typically leads to low head pressure rather than high. When refrigerant levels drop, the compressor may struggle to move refrigerant through the system, which can cause the pressures on the suction side to drop.

On the contrary, when a system is low on refrigerant, the suction line temperature would decrease, leading to low suction line temperature readings. Airflow issues can arise if there is insufficient refrigerant to absorb heat effectively, and an increased load on the compressor can also result from the compressor working harder to maintain cooling with inadequate refrigerant levels. However, high head pressure is generally an indicator of other issues, such as a restriction in the system or an overcharged system, rather than a symptom of low refrigerant.