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ymi2b 07-29-2010 11:08 PM

NEW sink and plumbing is slow draining, no overflow, pipes not clogged
3 Attachment(s)
I had an old sink that flowed fine.
I replaced the sink with a new one.
I also replaced drain pipes with new standard 1-1/4" p-trap but I had to be creative to make it reach the 2" waste pipe. SEE IMAGES ATTACHED HERE.
NOTE that the new drain pipe that sits in the sink itself does NOT have an overflow slit or whatever you call it, so my overflow hole in the sink never drains at all.

The problem is that this new drain piping is causing the water to flow out slowly. I THINK the problem may be because of the way I did the pipe adapters to get from the 1-1/4" to 2" waste pipe???? In the photos, does it look like it would cause a slow draining.

NOTE that when the sink has a pool of water, if I open and shut the drain stopper it almost always burps up bubbles and sometimes it will then suddenly drain normally/quickly. But as soon as I add more water I am back in the same situation.

I'm really annoyed because the metal drain that fits the sink was the only one I could find to fit the sink and it cost something like $45 which is rediculous when you consider that it does not even allow the sink's overflow hole to flow into it.

I'm really in need of some advice here.. it is disgusting to spit my toothpaste in the sink because I have to wait until it drains then hand-splash water on all the foam from the sides of the sink.

TheEplumber 07-30-2010 12:31 AM

I don't reconize that drain assembly but thats not the problem. You need to lower the trap so it connects directly to the wall stub out. In order to do this you will need to install a 11/4" slip joint tailpiece extension between your trap and the chrome drain assembly.

LateralConcepts 07-30-2010 10:03 AM


Originally Posted by TheEplumber (Post 477576)
I don't reconize that drain assembly but thats not the problem. You need to lower the trap so it connects directly to the wall stub out. In order to do this you will need to install a 11/4" slip joint tailpiece extension between your trap and the chrome drain assembly.

Right. That will give you a direct shot into the wall with your trap arm. You need to eliminate the two 90's. The first one isn't approved DWV fitting. It's schedule 80.

Also if the ABS coming out of the wall is 2", you need to reduce it to 1 1/2 then use an 1 1/2x 1 1/4 trap adapter.

Or your could just use an 1 1/2 trap and just use a 1 1/2 x 1 1/4 slip joint at the chrome tailpiece.

ymi2b 07-30-2010 11:30 AM

Thanks to both of you.
I assumed the muliple bends were obstructing the "flow" somehow...
I used to work in automotive engineering and with HVAC you want the air blowing as hard as possible so you try to minimize the number of bends and especially avoid 90 or less degree bends.
Of course, water and air engineering principles for "fluid dynamics" are pretty much the same...
But, I originally thought the draining is not a PERFORMANCE issue, meaning you don't need FAST flow, I figured the slowest point/bottleneck is at the sink's trap itself... Now my guess is that I've caused small "burps" at the 90 degree joint, kind of like turning a jug of water upside down, where it stops up for a moment and then either burps and lets a small gush of water out, or else it just only ever allows a small flow despite the large opening of the jug.

I'll let you know how it goes when I do my best to make it a straight shot to the wall stub.
..I was just tyring to optimize my storage space under the sink..

braindead 08-01-2010 05:51 PM

I know I'm late on this post but I have to put my 2 cents in.

That drain you have in your sink is wrong, most of those are used on vessel sinks which always have a draining prob:no:. you need to get one with the overflow holes in it and replace. Even with the pipes changed you will still have a problem.

ymi2b 09-22-2010 06:17 PM

braindead was right.

Here's what I did to fix the issue.

I used a grinding wheel on the outside side of the metal drain assembly and made a small hole at the same location where the sink's overflow drain hole is located (so it lines up correctly).

I then put everything back together and everything drained quickly as a normal sink would!

As for braindead saying it's the "wrong" drain, well, it's the only drain that Home Depot had that would actually fit that sink... and man it was expensive, like $45.

Logically, I still don't know why the overflow drain hole needs to be present. The in-the-wall waste line has the roof pipe vent the located very close to the sink's pipe entry to the wall, and that vent is not blocked at all.

:thumbsup:Oh well, it's working great, so I guess no need to think about it too hard at this point.

braindead 09-22-2010 06:43 PM

Try draining a bottle of water with the top submerged and see what happens, that drain assembly you have is for a vessel sink and they are known for not draining properly. :yes:

ymi2b 09-11-2014 04:07 PM

BrainDead's challenge fulfilled
Just replying almost 4 years later to BrainDead's challenge, haha!
Yes, if I fill the sink up to the high water overflow slit in the sink, it drains very slowwww, that is, until the water drains below the overflow slit in the sink, at which time the water slowly drains faster and faster until it goes quickly like a normal sink again. Thus, adding the slit in the actual metal drain pipe where the overflow channel of the porcelain sink joins at the bottom of the sink, thus allowing that overflow channel's air flow to join in at the metal drain, was essential to proper draining. My brain still cannot quite wrap around why this air channel is necessary, but it works and has worked well all these years. Also, note that the PVC piping I had in place remains the same, it may look odd, but I did that arrangement to make space under the sink, and I've had no problems, thankfully.

Ghostmaker 09-11-2014 06:04 PM

My two cents. The trap was raised above the vent which is not legal anywhere.

SHR Plumber 09-12-2014 04:58 AM

You should have cut out the entire drain pipe mess and started over. Let's see... ABS glued to PVC: NO. S-trap: sink drain not vented. Schedule 40 pressure 90 degree elbow: Clogs, clogs and more clogs. No primer used anywhere on the PVC: well maybe the fittings will just fall apart when touched and they can be returned for credit. The ABS drain pipe coming out of the wall is 1 1/2", not 2": your tape measure must have stretched out. Vessel sink pop-up assembly used on a standard sink: not made to work with that type of sink. No overflow drain in pop-up: wrong type of pop-up for the sink.

And the reason the sink drained slow is the surface tension of the water bridges the openings in the unvented, no overflow tube connection pop-up assembly and prevents the water from going down fast. That pop-up will always drain slow in any sink, it is designed that way. You chose the wrong pop-up for your sink. If it was recommended to you by a salesperson, you should have taken it out, brought it back to them and threw it at them as hard as you can. Home Depot stocks other drains for that sink.

Everything is wrong with this installation. My head hurts from looking at it too much. I am glad it worked out for you but it is a god awful installation.

ct18 09-12-2014 12:24 PM

I used to work in automotive engineering.

And this is why he doesn't respond well to people telling him that contraption is wrong. Engineers never do anything, just ask one. I deal with them on a daily basis.

Ghostmaker 09-12-2014 05:34 PM

Me to. I love ripping the plumbing drawings apart.

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