Service Call - Single system, Completed the HVAC heating and cooling inspection checklist. I ran the system in heat and cooling for 30 minutes and the system is operating according to specifications. I flushed the drain line with two gallons of water. I added drain cleaning tablets and endure to the system to assure it’s draining properly. Please refer to my Inspection checklist for more details. The system is in need of some repairs so we left the customer options to get the system back up and running to its optimum condition. Came and performed all sold work. After performing work we noticed that the zoning board was also bad and that the return had a damper on it that was jumped out between the thermostat side of the board. The zoning board needs to be replaced and the return damper needs to be removed.