Technician arrived and found small pool of water in lower left hand portion of drain pan. System drains were inspected and found to be functioning properly. CO2 cartridge was used to clear drain lines in both directions and are functioning properly. Edges of the drain and door were found to have cracked mastic sealant. New sealant and aluminum adhesive were used to reseal edges and prevent any condensation from accumulating in pan. Customer may want to use water phobic spray in drain pan and situation will be monitored to see if it persists.