The Sink drain broke so I replaced it.

Before sink drain replacement, everything was functioning properly until I disassembled abs piping out and the Rubber join coupler (abs 1 1/2 to copper 1 1/4). After reassembling it, the P trap is not draining correctly, and it only drains when the nut of the Rubber join coupler is kept loose ( Check photo ) .

However, if it is kept loose, it leaks drain water. Previously, the same Rubber coupler/joiner was working fine before I opened it.


Could you kindly suggest a solution for fixing this issue with the current setup?

Alternatively, would it be possible for you to recommend a better replacement or installation method that would prevent this issue from recurring in the future?

Unfortunately, I cannot remove the copper drain pipe as it goes into the basement, and it would be quite inconvenient to replace it at this time. Thank you for your kind assistance.

Removed Tee in last doesnt have any vent.









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You have an unvented 's' trap assembly and (probably) a 'partial' stoppage.

You will need an AAV added after the trap

BUT

first try to clear the stoppage.

NO CHEMICALS

Try a plunger - fill the sink and get the water ROCKING with occasional FORCEFUL downward pushes.

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



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I will install ABS vent,
As all the sink drains and pipes are out and disassembled, there is no clog anywhere.

I am confused by when you said its an S trap I have, but it looks like P trap. Can you clear this confusion?



thanks

You DO HAVE an "S" trap, and you also have a stoppage, or partial stoppage, which traps air in the inverted "U" section of the trap. Loosening the coupling allows the air to escape and allows the water to drain. The drain line is full of water, but will drain when water enters the pipe.

an unvented 'p' trap IS an 's' trap

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Which is why I said, "You DO have an 'S' trap.

I am having difficulty understanding why air in the trap, which affects pressures by at most 5in WC, prevents draining. When there is standing water in the sink, there is more than 5in WC of pressure forcing water into the drain pipe, so the water should still drain albeit more slowly because of the loss of 5in WC of pressure.

george.. i'm having trouble too.
if what our friend from SC says is happening then there are many thousands of the same type situation that wouldn't drain.

just so we don't look like fools, cut in an AAV.

Maybe the trapped air is not "in the trap", but trapped in the downstream piping BY the trap.

Even if there is air in the drain pipe downstream of the trap, the pressure from the standing water in the tailpiece and sink should force the air past any clog. even if slowly.

[www.plbg.com]

Ah! Lemon Plumber! I miss his posts.
In the linked thread, hj states that hydraulic principles hinder flow through double traps. I still don't get it.

to quote hj:


You DO HAVE an "S" trap, and you also have a stoppage, or partial stoppage, which traps air in the inverted "U" section of the trap. Loosening the coupling allows the air to escape and allows the water to drain. The drain line is full of water, but will drain when water enters the pipe.


me: loosening the coupling serves the same purpose as a piped vent except allows sewer gass(es) to potentially enter the habited space

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

I will cut a new AAV into the kitchen sink drain to fix this issue.

- What is the best way to connect abs to copper drain? should I stick to that frenco or there is any better idea.


- I would like to know why there is no AAV vent below the washroom sink I have? the washroom sink works works great but its smaller size than 1 1/2 kitchen drain pipe.

Cheers

The shielded coupling(Fernco) is fine to use. The lack of a vent isn't preventing the drainage, there's a restriction in the drain pipe. The vent keeps the trap from siphoning, which would allow sewer gas to enter the structure.

can someone please tell me, how do i connect copper pipe to abs without using Frenco?

I tried looking online for fitting for my copper pipe size and abs size but I didnt find any fitting for my copper pipe

copper drain pipe size is 1-1/4 Trade Size, 1.660 nom OD
ABS size is 1 1/2 inch.

Please share link for fitting

appreciate your help

you would have to solder some sort of threaded adapter onto the copper. then find a fitting to screw to it on one end and glue on the other. then you'd have to cut the plastic and glue a coupling in there.

1 1/2” sweat X male adapter

Then use 1 1/2” tubular piping, tubular tee air admittance valve then a tubular trap and continuous waste if needed

Or use a fernco, abs piping with a trap that has a union for easy removal of the trap

is the copper pipe 1 1/2 or 1 1/4.
I am so confused,
the OD i measured with caliper and the OD of the copper pipe is 1.6 inches

chart says its 1 1/4 inches pipe

please help

Copper "pipe" is different than copper "tubing"(DWV, or type M,L or K). 1 1/2" copper tubing is 1 5/8" OD(1.625" ). You have 1 1/2" DWV copper tubing.



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my friend from PA. tubular doesn't always fit inside a male adapter.

You're right packy, I should have said trap adapter or (desanco)



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They do sell this whole contraption in one bag.



If OP knows how to solder I would cut the copper and solder on a brass trap adapter and plastic tubular the rest of the way.



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