Performed maintenance on Lennox XP19 heat pump system in Aubrey, TX. Found condenser coil heavily soiled, reducing efficiency. Thoroughly cleaned coil using foaming coil cleaner and low-pressure wash. Tested electrical components, determining voltage enhancement module was faulty. Replaced failed enhancement module to restore proper voltage and amperage readings. Checked refrigerant charge, airflow, and all safety controls. Lubricated fan motor. Calibrated thermostat. Verified system operation across all modes. Improvements to condenser cleanliness and electrical components enhanced the heat pump's performance and energy efficiency.