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I have this style tub drain and can't figure out how it works. Does it simply block the flow of water when lowered? Or is there something more complicated happening?

My tub has stopped draining and when I removed the cylinder from the drain tower it came right out, but this did not affect the stoppage. I wonder if it should be attached to something, but can not see into the tube well enough.

I should add that I had been trying to unblock the drain and used a plunger on it. So there is a possibility that I plunged the clog(s) into a more blocking state, but I suspect that the pressure of the plunger interfered with something mechanical, because the water isn't receding at all, even after some hours.

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  • Where is the picture of the cylinder you removed? I would think it simply blocks the flow of water when lowered.
    – Dan D.
    Aug 2, 2014 at 20:26
  • @DanD. - I added a pic of the cylinder. Also, I had been using a plunger Aug 2, 2014 at 23:03
  • Never seen one of those before, but it looks like it would be a great place to run a plumbing snake...
    – Comintern
    Aug 3, 2014 at 2:07
  • 1
    Paul's on it, but... NEVER PUSH a plunger. ALWAYS PULL a plunger. Pushing will always drive the clog further in, pulling will pull it out where you can get to it and remove it entirely. If you push it further in, you always run the risk of making the clog WORSE. Aug 14, 2014 at 23:03

1 Answer 1


It's called a "standing waste". It works just like you say. The cone at the base of the inner tube seals against a flange and the water must fill the outer tube (attached to your floor) before (over)flowing down the inner tube. Here's a pic since words are useless for describing this kind of thing.

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Here's some in-depth discussion on resolving a clog on one of these.

if you see water in the tube at the same height as in the tub, you should snake down the tube. If not, the blockage is between the drain and the standing waste and you should snake down the tub drain.

I suspect the blockage is downstream of the standing waste since the plunger was ineffective. Try sealing the top of the standing waste tube while plunging before resorting to the snake.

  • I'd probably just snake the standing waste; plunging these usually just drives the water up the vertical cylinder. A snake is 10-15 dollars at a home improvement store.
    – gbronner
    Aug 13, 2014 at 14:41
  • @gbronner That's why I mention sealing (someone can just hold their hand over it) the standing waste before plunging. Sometimes the trap is silted up, in which case plunging can be more effective. I usually give the plunger a try before getting out the snake.
    – Paul
    Aug 13, 2014 at 17:05

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