Service diagnostic found that the condensation drain line was clogged. The primary drain line is missing a cap on the drain clear out to prevent attic air from getting sucked into the air handler. I also found that the blower wheel was dirty and there was biological growth on the primary pan and part of the evaporator coil. The secondary pan is not centered under the air handler and one corner of the air handler is extended over the edge of the secondary pan. Options for repair were presented to the clients. They chose to have the blower wheel cleaned, the drain line cleared and to sign up for maintenance. I cleared the drain line and flow tested the drain with two gallons of water. I also treated the drain line. I wiped away the visible biological growth. I pulled the blower wheel and cleaned it. I reinstalled the blower wheel and function tested the system. The system was running at the completion of service.