Performed A/C maintenance service at residence in Rosharonm. Unit is a 3-year-old Trane XR16, 3.5 ton system. Inspection revealed dirty condenser coils which were thoroughly cleaned using approved coil cleaner and low-pressure rinse. Checked refrigerant charge using subcooling method - system was slightly undercharged by 6oz, which was corrected. Inspected electrical components including capacitor (reading 43.8μF, within spec) and contactor (showing minimal pitting, still serviceable). Cleaned condensate drain line and installed new P-trap to prevent future drainage issues. Replaced air filter with customer-supplied MERV 8 filter. Checked supply register temperatures throughout home and identified one partially closed damper in guest bedroom which was corrected. System is operating at manufacturer specifications with 19°F temperature differential. Recommended quarterly filter changes and annual maintenance to maintain warranty coverage. All readings and recommendations documented in se