Performed routine maintenance on a residential air conditioning system. Followed lockout/tagout procedures, disconnecting electrical power supply. Conducted thorough inspection, checking refrigerant levels, operating pressures, and temperatures. Cleaned indoor evaporator coil and outdoor condenser coil surfaces using approved foaming coil cleaner. Flushed condensate drain line with nitrogen purge. Lubricated fan motors, inspected belt condition, and adjusted tension. Tested safety controls, electrical connections, and component operation. Restored power and validated system performance within designed parameters for peak efficiency and reliability. Provided detailed maintenance report with recommendations for any necessary repairs.