Complete member tune up. Customer is concerned about some biological growth that is forming around only (2) supply vents downstairs. I found that there is a gap between the ceiling and the grille causing our issue. The ducts and inside of the grille are clean. I caulked the edges of the grille to close the gap and ensure proper airflow on both vents. Inspect and change customer supplied filters. Clear all drain lines with vacuum. Central Air System (1): Inspect electrical components. Test amps and volts. Delta t measures at 20 degrees. Ensure system is running properly in all modes. A picture of the evaporator coil will be uploaded. There is no biological growth inside of this air handler. The UV device is functioning properly. All safety switches are functioning properly. At condenser checked pressures, temps, amps and volts. Left system in good working order. Central Air System (2): Inspect electrical components. Test amps and volts. Delta t measures at 19 degrees. Ensure system i