My house's water softener and salt tank overflow currently drain through what appears to be a drilled-out cast iron cleanout cap in the basement, close to where the sewer line exits the house. This causes problems such as sewage smells and is not to code. I would like to correct this by attaching a PVC wye with a no-hub coupler, leading to a air-gapped drain and trap for the water softener and a cleanout to reach the sewer lateral line.

My questions are:

  1. Can I get a no-hub coupler on the portion currently visible, or will I need to remove concrete around the pipe?
  2. Will I need to cut the pipe below the flange visible just above the concrete, or could the no-hub coupler attach onto it?
  3. What do I need to do to remove the old clean-out cap/remaining threads? It appears to be some kind of insert into the pipe.
  4. Does the proposed solution meet current code for Ohio?

Current situation: Current cleanout/drain

Current cleanout when open

Proposed solution:

Proposed solution

  • 3
    ...you have threads. Use them; threaded PVC adapters are a thing.
    – Ecnerwal
    Oct 9, 2020 at 17:47
  • 1
    It's not as visible as I hoped in the second picture, but there's nearly nothing left of the threads inside the pipe except rust (the cap is actually just perched on top of the pipe in the first image). I will look into re-tapping threads and a threaded PVC adapter as an option though.
    – kg333
    Oct 9, 2020 at 17:55
  • Is there alternative plumbing in the basement you can tap into to avoid having a pipe in the middle of your floor. FYI. What you are calling an air gap is an "air admittance valve".
    – Alaska Man
    Oct 9, 2020 at 19:19
  • This pipe is about 6-10 inches from the wall, so it's not too obtrusive. The next closest pipe in the basement is the main drain stack about 12 feet away, but the last owner built storage shelves around it which make it painful to get to. There is the kitchen drain pipe directly above, but I'm under the impression that won't work due to height.
    – kg333
    Oct 9, 2020 at 20:34
  • 1
    Regarding the air gap, I meant something like this, not an air admittance valve: homedepot.com/p/… It's to prevent a siphon in the water softener drain line.
    – kg333
    Oct 9, 2020 at 20:37

1 Answer 1


I agree with Ecnerwal, definitely use the threads for a much better solution. Don't worry about the iron's threads AT ALL, they'll cut and correct the wimpy PVC's threads as needed.

As a side note, concerning the VERY WRONG information out there about Air Gaps...usually from Home Inspectors. Air Gaps have absolutely nothing to do with sealing out smell, gases nor anything else. Air Gaps are nothing but a terrible back-flow prevention device.

Since this is a drain, you'll need to handle it, mostly (see below's opinion), like a sink drain, or more specifically, a laundry washer's standpipe to get it legal most anywhere.

You'd have a bottom shorter vertical straight pipe that leads up to a P-trap and another longer length vertical straight pipe (longer so volume can force out a clog) that goes up 30-inches, if possible, that you stick in or strap/wire-tie your hoses into.

I don't feel the vent and AAV in the image below are needed for your situation, as the open top of the Standpipe would be plenty of vent for your low-volume situation to flow properly. BUT, regulations may indeed require it, even though the pipe you're draining into is twice the size and doing the venting of anything nasty (technically,Standpipe Plumbing of a single fixture a wet vent)...you just need good flow.

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