Replaced the S-trap under sink...very easy job. However, water not draining & it makes no sense why it doesn't. I removed S-Trap then poured water directly into drain pipe up from basement, no problem. I then poured water directly into sink drain into bucket under sink, no problem. Add S-trap..no flow, clog. Configuration is EXACTLY as original. I even cut PVC to fit under sink. Is there S'pose to be vacuum pressure?

I am guessing that maybe you bumped the pop up assembly while working and the stopper is slightly lower than before, and there is an air bubble being formed under the pop-up and it is causing you to air lock. Try removing the pop up stopper and replace the bar back into the assembly and try pouring water down the drain again.

tailpiece too far into trap so it is hitting the bottom causing poor flow??

I'm an amateur, but I believe my kitchen sink just has the strainer assembly, no pop up. I rechecked the strainer & tailpiece. Thank you for responding.



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The tailpiece is fitted to seat inside S-Trap assy. I will re position & see what happens. Thanks. This may work.

You have a partial stoppage in the drain, which causes the drain to be air bound when you drain the sink. It is probably NOT the typical stoppage, but rather one that causes the line to have water in it, but still drain when you pour water directly down the drain.

Sorry, you didn't specify a kitchen sink. I don't normally see any unvented kitchen sinks; at a minimum, someone has usually installed an AAV on a T and used a P-Trap instead of an S-Trap.

It wouldn't make any difference if it were a "P" trap with and AAV or an "S" trap. NEITHER one will drain if it is air bound.

well, I've exhausted my options (snake, hot water, commercial drain cleaner). I truly appreciate your assistance. Gonna have to call a plumber if it doesn't clear by tomorrow. Thx...



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