Upon my arrival I evaluated 1 Trane heat pump system. Flushed and treated the water removal system. Cleaned the electrical cabinet and washed unit using water. Found the outdoor voltage enhancement system to be reading out of manufacturers range, customer was also concerned with the airflow of the system. Upon inspection I found that the downstairs damper was faulted and not closing when turned off, also found the plenum to be not sealed to the unit properly, needs to be properly resealed to unit upon repair. Sealing the plenum will be covered under labor warranty. Let customer know of my findings and presented options for repair. Customer wants options emailed over to her and will call with any questions.