The air filter had recently been replaced by the customer. I cleaned the condensate pan and drain lines and ran hot water to flush the debris and to check for proper drainage. I checked the electrical wiring and electrical systems, all are within specification. I operated the unit on second stage cooling mode and recorded 20+ degree delta temperatures across the evaporator coil. I confirmed proper flow rate and heat of rejection. I pressurized the ground loop to 65 psi. Unit operating normal.