re: A/C Repair Recommendation

Try the drain-o route as suggested and follow that with some really hot water. Also, there is an internal drain pile between your clean out and the unit, may have to take the panel off to access. Sometimes insulation gets loose and falls in and that will clog it up. If you have good drainage from where you pour bleach etc, trace it back to the unit, usually not more than 6-12 inches of pipe.

Good Luck brother