What indicates a problem with a malfunctioning heat pump in cooling operation?

A temperature differential that is too low is indicative of a problem with a malfunctioning heat pump during its cooling operation because it suggests that the unit is unable to effectively transfer heat from indoors to the outdoors. In normal operation, there should be a significant temperature difference between the air entering and exiting the system, indicating that the heat pump is removing heat efficiently. A low temperature differential means that the system is not cooling the air sufficiently, which can be a sign of issues such as insufficient refrigerant levels, compressor problems, or restrictions in the airflow.

While excessive noise, frost buildup, and unusually high energy consumption can also point to problems, these symptoms are more specific to different types of malfunctions. Excessive noise might suggest mechanical issues, while frost buildup often indicates problems with airflow or refrigerant levels that could lead to reduced efficiency. Unusually high energy consumption can indicate that the system is working harder than normal, but it does not specifically address a failure in the cooling function. In contrast, the temperature differential directly assesses the cooling performance of the heat pump, making it a clear indicator of operational issues.