Which of the following is a key indicator of a malfunctioning compressor?

A key indicator of a malfunctioning compressor is noisy operation. When a compressor is working correctly, it typically runs with a certain level of consistent operational sound, but any unusual or excessive noise can signal problems, such as mechanical failure, internal wear, or improper lubrication. Noises may include rattling, hissing, or grinding, which indicate that the components of the compressor are not functioning harmoniously.

In contrast, consistent temperature suggests that the compressor is maintaining its designated function, which is to regulate temperature as required by the system. Excessive cooling might imply that the unit is overworking or potentially malfunctioning but can sometimes occur if the thermostat is set incorrectly rather than indicating a direct compressor issue. Stable airflow is generally a sign of proper operation, indicating that the system is circulating air as designed. Thus, the presence of noisy operation serves as a more definitive indicator of compressor malfunction.