Gas and Oil Home Heating Furnaces - water below trane unit

can anyone lend some help. i am brand new to thread and am quite impressed with it. the problem is my central a/c unit. 2 days ago i noticed there was water leaking in my garage on the lower part of the wall that seperates the garage from the mud room. the central a/c unit is located in the mud room. i than took off the cover of the unit and cleaned out the pan. it was dirty and clumpy. i also looked outside to check on the drain. there was only 1 pc pipe outside and it came from underground to about a foot above ground in an "L" shape. there was goo, for lack of a better word hanging down from the pvc. i cleared off the pvc opening. is this the continuation of the drain to my unit, or do i have the wrong pipe? i restarted my unit the night before and everything seemed ok. yesterday am there wasn't any watwer build-up. but by yesterday p.m we had approx 6 in. of water below the unit. the pvc that exits the front bottom right of my unit curves after a few inches and runs down approx 4ft of wall than out approx 6more ft tahn turns again and proceeds approx 17ft out the wall.( i think)the unit is 6 years old and we have never had this problem. can anyone help? i read other posts but i don't think a shop/vac would work because of all the bends in the pvc drainpipe. would bleach do the trick, as someone else suggested? live in forida were a/c is on all the time. grateful for everyone's help.

The pipe you see outside is the termination of the drain. The L shape forms the trap. Try cutting the pipe near the inside unit with a hacksaw and pour a lot of bleach down the line and let it sit for a while. Then flush to the outside with a garden hose. Repeat this process a couple times. You won't believe the amonut of gunk that comes out. Since the unit is in the mud room, making some mess shouldn't be a problem. Now, take the shop vac and suck the out other end end of the pipe [or flush it out with the garden hose and let it run back into a bucket]. Do you have a snout type nozzle attachment for the shop vac? Use that in the drain pan to get any remaining gunk. Eyeball the piping inside to make sure it is sloped in the direction of flow. Then put the pipe back together with a pvc coupling. Don't just press fit together because it will leak. It needs to be glued together. Take a good look at the cooling coil to see how dirty it is. Clean as needed. You can look thru some of the recent posts for cleaning pointers. Now, suck the water from under the unit, put it all back together and see what happens.

you wont beleive this . my wife informs me that the shop-vac stopped working about a month ago. funny how things happen. anyway, what can i do if i do not have the shop-vac?can i still fill with bleach and than hose from the inside of house? how does the water and gunk go against gravity"up" the ending of the pipe outdoors. what can be done outside? can i cut off the ending and run bleach in there, than hose down? and if i do wont i just be pushing the gunk farther inside the pvc piping? i dont know anything about these units and am not particularly handy, sorry.

You want to flush from the inside to the outside. The other way around will push the gunk further up the pipe. Just cut the pipe, pour in the bleach [use a funnel if need be, one those funnels made for putting transmission fluid in cars is real handy, pour some in from the outside also] let it sit a while and flush it out. You have to do this 2 to 3 times because the slime likes to stay attached to the pipe. The water drains out now by gravity and is able to overcome the trap, so you can imagine that, with pressure behind it, it come flying out and push the gunk out. Since you have to go to a home center/Sears/Home Depot anyway to get the pvc coupling, pvc glue and pvc cleaner. perhaps you could invest in a new one or two gallon shop vac. You want the wet/dry model; they're so handy around the house. When you go to put the pipe back together, the ends have to dry or the glue won't stick. Swab the ends of the pipe and the inside of the coupling with the cleaner, and wait for it to evaporate. Then apply a coating of glue to the ends of the pipe and attach the coupling to each end of the pipe. Plan ahead a little, because once you apply the glue, you have to work quickly. The glue sets up in about a minute.

couldn't have done it without you. when i cut the pipe it was totally blocked. thanks for the insight. i can only imagine what it would have cost me to have it repaired. the $20 at home depot was a bargain. thanks again.