If the compressor oil on a hermetic compressor is acidic, the next step is to change the:

• A. System filter driers repeatedly.
• B. The refrigerant oil only.
• C. The evaporator coil.
• D. The condenser fan motor.

Answer: (A)

Acid in the compressor oil means the system is contaminated with acids that can corrode copper, degrade oil, and damage seals. The filter drier contains desiccants and acid-scavenging materials that remove moisture and acids from the refrigerant circuit. Replacing the filter drier is the first line of defense, and doing it repeatedly helps ensure any residual acids stuck in oil or dryer material are removed before the system is recharged. Changing the refrigerant oil alone won’t eliminate the acids you’ve found, since new oil can become contaminated again, and the acid issue persists throughout the circuit. The evaporator coil or condenser fan motor don’t address the chemical contamination, so they aren’t the appropriate remedy in this situation.