I have an air exchanger in my attic leaking water into my ceiling. I cleared the pan drain for what I hope is a temp fix however I cannot get the water to come out the main drain. I took it loose and could see water in there and put a shop vac on the line to make sure it is clear. Until all this started I didn't even know there were 2 drains and I can't ever remember any water coming out of the main drain so this may have been this way since day 1. I checked the unit for being level and although not perfect it was very very close. Any ideas?? Good grief its hot up there.