On arrival customer advised that carpet was wet near furnace. Inspected drain lines and checked filter (16x20x1) and also verified proper refrigerant charge. Determined drain line was blocked. Completed PVC rebuild just from coil to existing gravity drain. Overall system is 20 years old and we recommend upgrading the equipment. Customer is open to getting a quote to upgrade. Indicated that it is not urgent. Will involve a site visit to discuss specific details such as lineset placement and other changes that are not routine with just an equipment swap out. System currently operable and draining properly. ADP COIL M#HA04236E170B180573, S#6002G36114. (16x20x1) filter.