The AC unit condensation drip tube runs into 1” black tubing that then disappears into the floor slab. I have always assumed that it connected into the main sewer line. This past winter I replaced all of the under slab cast iron sewer pipe with PVC and found no such connection. Never saw the black tubing at all.

Now the condensation tube is blocked and water is all over the floor. Assuming that the original contractor would not have just ran it under the slab and ended it, my next guess is that it runs out under the foundation and into the yard. However, the wall it would run under is about 3’ below grade, so it would need to run a fair distance to be level and come out of the ground. The house was built in the early 70’s and does not have floor drains in the basement.

Am I missing something here? Where could this thing go? Has anybody seen this sort of set-up before?

Thanks
Scott

The AC unit condensation drip tube runs into 1” black tubing that then disappears into the floor slab. I have always assumed that it connected into the main sewer line. This past winter I replaced all of the under slab cast iron sewer pipe with PVC and found no such connection. Never saw the black tubing at all.

Now the condensation tube is blocked and water is all over the floor. Assuming that the original contractor would not have just ran it under the slab and ended it, my next guess is that it runs out under the foundation and into the yard. However, the wall it would run under is about 3’ below grade, so it would need to run a fair distance to be level and come out of the ground. The house was built in the early 70’s and does not have floor drains in the basement.

Am I missing something here? Where could this thing go? Has anybody seen this sort of set-up before?

Thanks
Scott

Hi Scott,

By code you may not discharge a sump pump, condensate or rainwater run off into the sewer. Our condensate lines clog up from time to time. Since most lines are 3/4"PVC you can't snake them out so we take a air tank and blow them out. This could also be a dandy way to locate the terminal end.
Cheers, Tom

IF you can actually see where the tubing runs from the pan and into the slab, then I would guess that he kept in just under the slab and ran it out the side of the house above the grade line. Have you ever noticed a damp spot around your house in the summer time? How about a spot that has more weeds? You said you replaced the sewer line under the slab? DId you need to sawcut all of that? I am very interested in that? Please let me know. Thanks, Darrel. P.S. just for the heck of it I will let you know that when they can, because the A.C. unit is above the 1st floor the plumbers have been known to drop that hose into a vertical wye branch tail piece just above the trap under a lav sink. Just in case that's possible.

''Assuming that the original contractor would not have just ran it under the slab and ended it,''??

My house was built in 1970. Since the A/C was a Sears unit, I doubt the original contractor was guilty of installing it. I am on a crawl space. The condensate drain simply ran down into the crawl space.

As usual, your best bet is to follow Tom's instructions to the letter. Maybe you will find where it comes out, and maybe not.