What symptom might indicate a refrigerant leak in a system?

A refrigerant leak in a refrigeration system can often be identified by the presence of clear or oily spots around connections. This is due to the fact that refrigerants are often mixed with oil to lubricate the compressor. When a leak occurs, the refrigerant can escape, and the oil may accumulate at the points where the refrigerant is escaping. The presence of these oily spots is a clear visual indication that there may be a leak in the system.

In contrast, while higher temperatures in the compressor and rapid cycling of the compressor can certainly point to various issues within the system—including potential refrigerant problems—they are not definitive indicators of a refrigerant leak specifically. Frost buildup on the evaporator coil can suggest a low refrigerant level, but this also has other causes and does not provide the same direct visual evidence of a leak as the oily spots do. Hence, the oily spots serve as a specific and definitive symptom to investigate further for potential refrigerant leaks.