A major repair under EPAs regulations would be

• A. Replacing a pre-filter
• B. Lubricating moving parts
• C. Cleaning the condenser
• D. Replacing a condenser coil

Answer: (D)

Under EPA rules, a major repair means replacing a major component of the refrigeration system or otherwise performing work that affects the system’s performance, which typically requires recovering the refrigerant before the work and recharging afterward. Replacing a condenser coil fits this because the condenser is a major part of the refrigerant circuit; removing or replacing it involves opening the system, handling refrigerant, and then recharging and testing the system. The other tasks are routine maintenance or minor replacements that don’t involve opening the refrigerant circuit or changing a major component: a pre-filter is just a filter, lubricating moving parts is regular lubrication, and cleaning the condenser is cleaning. So replacing the condenser coil is the major repair.