I have a problem that has stumped both an AC tech and a plumber. I have an acadian style house. On the back porch, there is a wet spot on the ceiling in the same location where the upstairs AC is. We had the drain line checked (clear) and the plumber thought the drain elbow (under the eaves floor) might be cracked so he rerouted the drain and wrapped the pipe. The wet spot remains. The unit is completely clean and dry. My eaves are dry also with no apparent leaks anywhere. The consensus seems to be condensation in the subfloor of the eaves that is dripping down. But from what? The drain line is dry with no leaks and is above the subfloor. Meanwhile the wet spot continues to damage the wood. Has anyone else had this problem or have any suggestions for where else to look?

Has anyone opened up the ceiling and tracked the leak back to the source? There's just got to be a way to locate this. No moisture whatsoever around the AC collection pan or drain line? How about the cooling coils could condensate be coming from there? Let me know, Tom