I pressurized the ground loop to 65 psi and confirmed proper flow rate and heat of rejection. The drain was very slow to drain, but cleaning the drain pan and drain line is part of the maintenance. I poured water through the drain after cleaning and it drains quickly. I checked the electrical wiring and electrical systems, all are within specification. Unit cooling with 20+ degree across the evaporator coil. Unit operating normal. I’m regards to customer concern with stale odors from the unit and previously been told about ultra violet lights, I informed the customer that W.F. prohibits UV lights from shining on the coil surface, either front or back. I suggested Apco Air Scrubber as a better solution. I sent product literature to the customer and made an estimate.