For this job I performed a drain clear from under the sink Upon disassembling the sink pipes I found corrosion in the main sewage line to the home This was likely the main reason why the ac system drain line was backing up I cleared it and also assembled a new connection for under the sink Will need to come back to paint under the sink, I accidentally spilled primer Homeowner is aware that I made the mistake, They are o k with me coming back to paint ***Adam arrived while I was still at the call to fix problem with sink****