Air Conditioning Repair Certification (ETI) Practice Exam

One primary cause of compressor overheating in an AC system is indeed a lack of refrigerant or poor airflow. When the refrigerant levels are low, the compressor has to work harder to circulate the limited refrigerant throughout the system. This extra effort can lead to increased temperatures within the compressor, which may result in overheating.

Additionally, poor airflow, whether due to dirty air filters, blocked ducts, or malfunctioning fans, can prevent heat from being effectively expelled from the system. This lack of airflow not only reduces the cooling efficiency but also traps heat within the compressor and evaporator coil, exacerbating the overheating issue.

Excessive refrigerant can lead to different issues, such as high pressure in the system, which can still affect temperature but not in the same direct manner as insufficient refrigerant or poor airflow. Similarly, while high ambient temperature can affect the overall efficiency of the system, it is not a direct cause of compressor overheating. Faulty thermostats may lead to incorrect readings or controls, but they do not inherently contribute to overheating unless they cause the system to run continuously without proper cycling.