Came out to call for a system not draining properly. Customer has a home warranty plan and they have another company coming out to fix a txv issue this coming week, but since that company came out Wednesday he’s had another issue with his drain pipe not draining water properly and causing the pan to fill up with water. Customer stated he had a friend out earlier that has some hvac background and said it’s the drain line clogged up. Tried to use a shop vacuum but it didn’t work. Needed it blown out with compressed air. I checked the drain over and indeed found the drain backed up. Customer was concerned that the last techs that have come out for the AC service may have not checked the drain. I reassured customer that we do our best to make sure everything is functioning properly. Told him I would take care of the drain issue. Flushed the line out with nitrogen and heard the drain clear thoroughly. Told him that since we already knew what the issue is that I would just charge a test and