Came out today for a no ac call. Upon arrival I was told that the secondary pan had filled up and the office had someone clean out the water and blow compressed air down the clogged drain line. After the drain line was fixed the system just wouldn’t start. Upon inspection I found the thermostat batteries needed to be replaced. I replaced the batteries and called for ac. The system started right up. I checked the drain line by flushing it with multiple bottles of water. I found that the drain line was still clogged. I blew out the line again using the Gallo gun. I tested the line again and it drained properly. I was told that this is the second time the system has clogged. I advised that the drain line should be replaced due to the condition of the drain inside. Nordyne system model #b5bmt48kc, serial #b5d080709286.