Which of the following is a symptom of frost developing on a suction line?

The correct answer highlights that low system pressure is indeed a symptom of frost developing on a suction line. When frost accumulates on the suction line, it indicates that the refrigerant is not absorbing heat effectively, which typically occurs due to inadequate refrigerant levels, low airflow, or thermal insulation issues.

In a properly functioning system, the suction line should be warm, indicating that the refrigerant is absorbing heat from the air being cooled. When the pressure is low, it means that the refrigerant is not circulating properly, which can lead to a drop in temperature and the formation of frost.

Recognizing this symptom is essential for diagnosing refrigerant flow problems or airflow obstructions within the system. Addressing low pressure and the resultant frost buildup can prevent further operational issues and ensure the system runs efficiently.