TexasCHLforum.com

...cut the pvc pipe about 6" above where it goes into the larger pipe...measure the inside of the larger pipe that goes into the slab...buy at Home Dippy or Lowes a black rubber bulb that goes on the end of your garden hose...when you put that down into the larger pipe...(get the right size range i.e. 1"-3"),,,hold it in place about 1' in...have someone turn the water on...as the pressure builds, the bulb will swell and seal...the pressure will blow out the drain, which, if it's gone larger than where it comes out of the pan under the AC coils, does drain into a house drain...let it run a minute or two then cut off the water and remove it...pour water from the hose down the big pipe to be sure it's open......then use the augur 1/4" in a spin housing of plastic...less than $20 to clean the smaller pipe...from the top where you pour in the bleach monthly, if you can make all the turns...or from where you cut it...messier...get a plastic coupling and push the smaller pvc into it and wrap it with black tape...you'll prolly have to do it again sometime so don't glue it...

...put a day on the calendar in red each month to pour about a cup of bleach down the small tube from an opening which should be at the top of it...