ESCO Air Conditioning Practice Exam

A broken reed valve is the most probable cause of noise and hot running in a compressor after repairing and recharging an air-conditioning system with a liquid line leak. Reed valves play a crucial role in regulating the flow of refrigerant within the compressor. If a reed valve is broken or damaged, it can disrupt the compression process, leading to noisy operation and increased heat generation. This issue can directly impact the efficiency and performance of the compressor, resulting in overheating and potential damage.

Option B, a faulty condenser fan motor, may cause the system to run hot but is not directly related to the compressor noise. Option C, a high refrigerant charge, can also cause issues in the system, but it usually does not lead to noisy compressor operation. Option D, low oil in the system, could potentially cause compressor failure but is not the most probable cause for noise and hot running after repairing and recharging the system with a liquid line leak.