I installed a new vessel sink without an overfolw and it drains very slow. When I loosen a connection and let some air in it drains fine, just like it did with the original undercounter sink. So I assume I need to do something to compensate for the lack of an overflow. Any suggestions? Thanks.

I installed a new vessel sink without an overfolw and it drains very slow. When I loosen a connection and let some air in it drains fine, just like it did with the original undercounter sink. So I assume I need to do something to compensate for the lack of an overflow. Any suggestions?. Thanks.

Is the sink just resting on a slab countertop with the connections underneath exposed?

Or is this a vanity situation with doors and unexposed connections underneath?

If it is a vanity, you can put in a sanitary tee laying on its back where the drain comes out of the wall and install an air admittance valve.

I installed a new vessel sink without an overfolw and it drains very slow. When I loosen a connection and let some air in it drains fine, just like it did with the original undercounter sink. So I assume I need to do something to compensate for the lack of an overflow. Any suggestions?. Thanks.
Thanks. Most of the plumbing is hidden in a cabinet. What is an air admittance valve and where can a find a picture or sketch re. installing it? Is this a common problem with vessel sinks? Can I just buy one of those bottle drains like Deco sells instead?

Thanks. Most of the plumbing is hidden in a cabinet. What is an air admittance valve and where can a find a picture or sketch re. installing it? Is this a common problem with vessel sinks? Can I just buy one of those bottle drains like Deco sells instead?

Tom posted a really good picture of the set-up in another thread. (https://www.askmehelpdesk.com/plumbing/kitchen-sink-back-up-38861.html?highlight=air+admittance)

As for the bottle trap, it isn't going to help you with this situation.

Learned that the problem is with a lack of air ahead of the P Trap. Does anyone know if codes will let me put the air admissions valve in front of the P trap?

I installed a new vessel sink without an overflow and it drains very slow. When I loosen a connection between the sink and P Trap and let some air in it drains fine, just like it did with the original undercounter sink that had an overflow. So I assume I need to do something to compensate for the lack of an overflow. Does anyone know if Codes will let me put an air admissions valve in front of the P trap? Thanks.

You have installed a standard lavatory drain on your vessel sink and now you are air locked.
You need a vessel sink drain,(see image) For $31.00 this can be remedied. Click on; http://www.nextag.com/vessel-sink-pop-up-drain/search-html
To check it out.
Good luck, Tom

I installed a new vessel sink without an overflow and it drains very slow. When I loosen a connection between the sink and P Trap and let some air in it drains fine, just like it did with the original undercounter sink that had an overflow. So I assume I need to do something to compensate for the lack of an overflow. Does anyone know if Codes will let me put an air admissions valve in front of the P trap? Thanks.

Putting the AAV in front of the trap will suction the trap dry.

I still think your problem has to do with your vent.

It is either plugged, non-existant or is blocked by the bend of the trap that goes into the wall.

Some people make the mistake of pushing the bend all the way into the back of the fitting, which blocks the drain opening.

As for compensating for the lack of an overflow, look at it this way, kitchen sinks, bar sinks, mop sinks and floor sinks all drain just fine without an overflow -- Your lavatory isn't any different.

Tom - How does a vessel sink drain work? Thanks - Dennis

Hey Dennis,

In a regular lavatory the over flow acts as a vent. You do not have this in a vessel sink so a drain with a opening in the tailpiece that acts as a vent takes the overflows place.

You said, "Learned that the problem is with a lack of air ahead of the P Trap."
Entirely correct and a drain that's made especially for vessel sinks addresses that problem.
This is not a venting problem. Your house vent relieves the suction caused by the discharge leaving the trap.
A vessel sink generates suction BEFORE it gets to the trap and that's what slows down the action. Change out the drain and your problem disappears. Good luck, Tom

Hey Dennis,

In a regular lavatory the over flow acts as a vent. You do not have this in a vessel sink so a drain with a opening in the tailpiece that acts as a vent takes the overflows place.

You said, "Learned that the problem is with a lack of air ahead of the P Trap."
Entirely correct and a drain that's made especially for vessel sinks addresses that problem.
This is not a venting problem. Your house vent relieves the suction caused by the discharge leaving the trap.
A vessel sink generates suction BEFORE it gets to the trap and that's what slows down the action. Change out the drain and your problem disappears. Good luck, Tom

Thanks. I boought a grid drain for vessle sinks and it made no difference. Interestingly, I stucj a straw down one of the grid holes and then all worked OK. It seems likse the individula grid drain holes were too small, I need to try the vent solution, or I simply need a wide open drain hole. Commnets??

Speedball: From the research I have done online I think the drain in the picture is for a sink with an overflow. In my vessel set-up the sink sets on a countertop and is connected to the tail piece under the counter, so there is nothing the vent holes shown in the picture are open to - i.e. they have to be below the vessel and are either facing the countertop or open to the air space under the cabinet, I which case a block could cause water to overflow into the cabinet. Does this make sense?

Speedball: From the research I have done online I think the drain in the picture is for a sink with an overflow. In my vessel set-up the sink sets on a countertop and is connected to the tail peice under the counter, so there is nothing the vent holes shown in the picture are open to - i.e.,they have to be below the vessel and are either facing the countertop or open to the air space under the cabinet, i which case a block could cause water to overflow into the cabinet. Does this make sense?

Can you post a picture of the drain set-up underneath the countertop?

That would be very helpful.

Here's another grid drain designed for lavatorys without overflows.

http://www.homedepot.com/prel80/HDUS/EN_US/jsearch/product.jsp?pn=100088013

If you go to this website you will see the Kohler grid drain for vessel sinks does not have the vent openings.

http://www.us.kohler.com/onlinecatalog/detail.jsp?item=5870102&section=2

Yes the golden color grid drain is just like the one I have - it has no vents. Now you know what my set up looks like. I guess I am wondering if the vessel sinks which do not have overflow vents have an inherent design problem. This is why I am going to try using a vent in between the Ptrap and the sink - much like a vacumm breaker, unless someone else has any other ideas. As a follow-up - the straw I used to test the vacumn theory was inserted in one of the grid drain openings. As long as the straw was above the level of water entering the sink, the vessel drained normally. When water got above the top of the straw or when there was no straw the drain started to work slow. This is why Iam pretty sure that either the grid drain holes are too small, or the lack of a vent / air is the cause of the problem. Thanks again.

[QUOTE=notmyjob]hey racroo,
I am having exactly the same problem as you with the slow draining of a vessel sink. Have you found a solution? I would appreciate any help you could pass on. -Carl[/QUO

First, put a long straw into one of the grid drain holes (or into the drain if you have a different style drain). If you see the water drain faster, then you know that the lack of an overflow is causing the problem. I put an air vent (vacuum breaker) in front of the P Trap and that made a slight difference - only cost ~$10 for the vent plus a T fitting and elbow at Home Depot which I attached to the tail pipe inside my pedestal cabinet. I also filed the drain holes a bit to make them bigger, which helped too. What would certainly fix the problem would be to have an open drain with a stopper, but I decided that it now drains OK. You could also shut off the supply valves a bit to slow the water inflow. Let me know if any of this helps.

I have a danze faucet with an overflow drain pipe. I want to be able to use the rod to actuate the stopper and didn't want to have to spend $80+ on each drain as I have 5 vessel sinks with danze faucets.

What can I do to reengineer that opening made for the overflow? Is there a T pipe out there that can be mounted?

Chris

I too have the same problem.
Basin sink with no overflow drains really slowly (and passes the straw test).

So far I've heard that yes, an Air Admittance Valve will work, and no it won't. Which is it?!

Racroo - it sounds like your solution worked (and it sounds like a form of an Air Admittance Valve). But by "in front of" the P-trap, do you mean between the trap and the sink, or between the trap and the plumbing in my walls?

Also, if a vacuum breaker or Air admittance Valve will work, how high does it have to be? I've heard 4 inches above the weir. But I'm not sure I have that clearance inside my cabinet, and I REALLY don't want to start busting holes in the walls to install this. (I can't install, even a nice looking breaker above the platform of the sink, as the basin sits on a granite top that I am just not cutting through.


Any ideas from people who have actually solved this problem?

My sink now works great without the air valve (which was placed between the Trap and the sink drain tail pipe. What I did was replace the grid drain with a mushroom cap drain that has a much larger opening (three large openings to be specific). When you look at the total area of the three opending vs. the little grid drain holes it is MUCH bigger. I'm convinced if you really want the grid drain look another option would be to enlarge the holes, or try a different grid drain with larger or more holes. In any case, do not make the mistake of using a drain meant for a sink with an overflow as it will not work / could leak. If you decide to enlarge the holes, like I did as part of my first attempt at a fix, I found the air valce helped a bit, still not as good as the improvement when I swithced to the musahroom cap. Incidentally, both of the drains I used were by Decolav. Let me know if this helps.

Hey y'all! We just purchased a lovely vessel sink WITH overflow, and a totally cool faucet. You already know what the problem is, most likely. Yep, slow draining! Here's the question: The faucet came with a simple "grid" drain, (no stopper) not a pop up. From all the questions and answers I've been reading about sinks, drains, etc. on here, I'm wondering if we should remove said drain, and install one of these pop-up's? When I'm washing my hands, when I get done and the water is slowly draining, if I run my fingers right across the grid a time or two, the water drains out quickly.

The house is 136 years old, but the plumbing, thankfully, is at the most only 15. Following all your advice posted here, I've checked all the fittings and seals, made sure all visible pipes are clear, run hot-hot water until I drained the tank (and damn near melted the plumbers putty!), plunged gently... then forcefully, yada yada yada. The tub and toilet have no problems. The only thing I have not done is snake.

Should I try the pop-up drain thing first? I would WAY rather do that than see what's up in the walls, and I don't CARE that it's only ten to fifteen years old! NOT something I want to know! EEEEEWWWWE! Thanks much... Tina :p

The reason you have a drain problem that can be cured by running your finger
Across the drains grid is the grid holes are so small they set up "surface tension". Click on, http://www.bathroom-glass-vanities.com/umbrella-drain.html?source=nextag to find a pop up drain for vessel sinks that really drains. Regards, Tom

My sink now works great without the air valve.... What I did was replace the grid drain with a mushroom cap drain that has a much larger opening (three large openings to be specific).


Awesome, this is what I was hoping to hear, not having to bother with an AAV.
I'm planning on ordering a push-button or pop-up mushroom drain for the non-overflow basin. (That way I won't need a stopper when I do want to fill the basin.

Thanks for your input... I feel better now hearing about someone's "proven" solution.



Thanks,

Toast

Let me give you a link to a vessel sink umbrella type drain; http://www.bathroom-glass-vanities.com/umbrella-drain.html?source=nextag

What can be done to correct a very slow draining vessel sink?

Hey y'all! We just purchased a lovely vessel sink WITH overflow, and a totally cool faucet. You already know what the problem is, most likely. Yep, slow draining! Here's the question: The faucet came with a simple "grid" drain, (no stopper) not a pop up. From all the questions and answers I've been reading about sinks, drains, etc. on here, I'm wondering if we should remove said drain, and install one of these pop-up's? When I'm washing my hands, when I get done and the water is slowly draining, if I run my fingers right across the grid a time or two, the water drains out quickly.

The house is 136 years old, but the plumbing, thankfully, is at the most only 15. Following all your advice posted here, I've checked all the fittings and seals, made sure all visible pipes are clear, run hot-hot water until I drained the tank (and damn near melted the plumbers putty!), plunged gently... then forcefully, yada yada yada. The tub and toilet have no problems. The only thing I have not done is snake.

Should I try the pop-up drain thing first? I would WAY rather do that than see what's up in the walls, and I don't CARE that it's only ten to fifteen years old! NOT something I wanna know! EEEEEWWWWE! Thanks much..... Tina :p
We had a pop up that was slow. We had the plumber put in a flat screen. It is still slow. I am pissed.

I have a Vessel sink with an overflow and it is slow. I don't think it is a vent problem. Is the drain pipe smaller?

I have a Vessel sink with an overflow and it is slow. I don't think it is a vent problem. Is the drain pipe smaller?
Lavatory drain pipes have always been 1 1/4". Your vessel sink has a over flow built in the sink? What type of drain do you have? Did the lav you replaced drain good before you replaced it with a vessel sink?
Your turn, Tom

Please read the posts on this page. They deal with your problem and that's venting the drain on a vessel sink. More questions? I'm as close as a click. Tom

What's deal? Did everyong just get Vessel sinks and they all stink?
We just got one with a lift plug, it was slow, we changed it to a plain drain and it is still slow.
What is wrong with them?
Does anybody really know?
Bruce

My sink now works great without the air valve (which was placed between the Trap and the sink drain tail pipe. What I did was replace the grid drain with a mushroom cap drain that has a much larger opening (three large openings to be specific). When you look at the total area of the three opending vs. the little grid drain holes it is MUCH bigger. I'm convinced if you really want the grid drain look another option would be to enlarge the holes, or try a different grid drain with larger or more holes. In any case, do not make the mistake of using a drain meant for a sink with an overflow as it will not work / could leak. If you decide to enlarge the holes, like I did as part of my first attempt at a fix, I found the air valce helped a bit, still not as good as the improvement when I swithced to the musahroom cap. Incidently, both of the drains I used were by Decolav. Let me know if this helps.



UHG!!

Well - I installed a Decolav pop-up mushroom drain. Didn't work at all. Everything is still slow. However I think that part of the problem is the trap piping. AFTER the P-TRAP, the pipe leading to the wall goes straight up almost to half the height as back up to the sink's drain. (And the P-TRAP is 1'5" lower than the sink drain). So my thoughts are that there is too much space to go back up after the trap, and without a lot of pressure the water will not drain right. (Though the old sink worked just fine, weird.)

At this point, I already have a nice hole in the wall. So I plan on seeing how faw down I can rip out the PVC pipes (post P-TRAP), a then run a flex-tube pipe downward from the P-TRAP to the now shortened pipes behind the wall.


Can someone confirm the following though:

1) That if I decide to throw a AAV (Air Admittence Value) into the mix, whether I install it between the sing and the P-trap, or between the P-Trap and the pipes in the wall?? (I may shorten the pipes as I said above, AND install the AAV 9as the nuclear option).

2) Are there any screw-on based parts from going from one pipe size to another? All my local hardware stores seem to have are non-screw-on tubes with rubber washers/seals (like one pipe having sex with another larger pipe and an o-ring to keep them air/water tight). Logically these non-screw ones 'should' work given there is normal pressure, but I think the backup in my pipe is causing them to leak. (Guess my mistake is going to Home Depot instead of Lowe's... huge difference in customer service).

If that STILL don't work, screw-it, I'm removing the P-TRAP together and will try to find some sort of gravity/spring valve to let water down, and keep the air from coming up from the outbound pipes.



Moral of the story: I think it's better to have a crappy old ugly sink that works, than a fancy new one that don't.

UHG!!!!

Well - I installed a Decolav pop-up mushroom drain. Didn't work at all. Everything is still slow. However I think that part of the problem is the trap piping. AFTER the P-TRAP, the pipe leading to the wall goes straight up almost to half the height as back up to the sink's drain. (And the P-TRAP is 1'5" lower than the sink drain). So my thoughts are that there is too much space to go back up after the trap, and without a lot of pressure the water will not drain right. (Though the old sink worked just fine, weird.)

At this point, I already have a nice hole in the wall. So I plan on seeing how faw down I can rip out the PVC pipes (post P-TRAP), a then run a flex-tube pipe downward from the P-TRAP to the now shortened pipes behind the wall.


Can someone confirm the following though:

1) That if I decide to throw a AAV (Air Admittence Value) into the mix, whether I install it between the sing and the P-trap, or between the P-Trap and the pipes int he wall???? (I may shorten the pipes as I said above, AND install the AAV 9as the nuclear option).

2) Are there any screw-on based parts from going from one pipe size to another? All my local hardware stores seem to have are non-screw-on tubes with rubber washers/seals (like one pipe having sex with another larger pipe and an o-ring to keep them air/water tight). Logically these non-screw ones 'should' work given there is normal pressure, but I think the backup in my pipe is causing them to leak. (Guess my mistake is going to Home Depot instead of Lowes... huge difference in customer service).

If that STILL don't work, screw-it, I'm removing the P-TRAP together and will try to find some sort of gravity/spring valve to let water down, and keep the air from coming up from the outbound pipes.



Moral of the story: I think it's better to have a crappy old ugly sink that works, than a fancy new one that don't.

(1) you shouldn't have to add a AAV.
(2) I take it you're looking for a 2 X 1 1/2" reducing coupling (see image) To check farther click on, http://secure.data-comm.com/RBIS/Detail.bok?no=79665
(3) you're not going to find any. Spring loaded and mechanical traps are outlawed.
Good luck, Tom

I installed a new vessel sink without an overfolw and it drains very slow. When I loosen a connection and let some air in it drains fine, just like it did with the original undercounter sink. So I assume I need to do something to compensate for the lack of an overflow. Any suggestions?. Thanks.

Here is the solution that my contractor came up with:
Vent the drain by adding copper tubing out of the drain just below the vessel, through the wall, to a height exceeding the height of the vessel. (see attached photos)
This solution provides a safe air admittance route to the drain pipe on the vessel side of the P-trap where it is usually provided for by sinks with overflows. The copper tubing will never overflow in the wall because it is higher than the height of the vessel. The vessel will always overflow first in the unlikely case of an undetected clog in the P-trap, the same risk that exists if there is no air admittance tube.
If the homeowner is afraid to drill a hole in the wall, the air admittance tube can terminate as high as possible within the cabinet, or the tube can be run through a hole in the countertop behind the vessel.
This solution allows the continued use of the attractive and unobtrusive grid drains in the vessel.
With the air admittance tube connected the vessel drains very, very quickly.
I think that this solves the only potential drawback to using these beautiful vessels.
afiore

afiore
New Member Join Date: Dec 2006
Posts: 1


--------------------------------------------------------------------------------

I am so happy with the solution I want to share it with you.

Here is the solution that my contractor came up with:
Vent the drain by adding copper tubing out of the drain just below the vessel, through the wall, to a height exceeding the height of the vessel. (see attached photos)
This solution provides a safe air admittance route to the drain pipe on the vessel side of the P-trap where it is usually provided for by sinks with overflows. The copper tubing will never overflow in the wall because it is higher than the height of the vessel. The vessel will always overflow first in the unlikely case of an undetected clog in the P-trap, the same risk that exists if there is no air admittance tube.
If the homeowner is afraid to drill a hole in the wall, the air admittance tube can terminate as high as possible within the cabinet, or the tube can be run through a hole in the countertop behind the vessel.
This solution allows the continued use of the attractive and unobtrusive grid drains in the vessel.
With the air admittance tube connected the vessel drains very, very quickly.
I think that this solves the only potential drawback to using these beautiful vessels.
afiore

The problem with the copper pipe option is that if a clogged trap temps someone to reach for a plunger (a normal method in my books) the excess water will not push through the blockage but rather out the copper 'vent'. If this is in the wall you run the risk of pushing water into the wall cavity and causing all sorts of problems. The other problem is that it is hidden. It would be hard for someone to quickly asses what was done and why.

In my opinion, an AAV between the sink and traps works best (I have has great success with it) and will cause no future problems. Also, if there ever is a problem, than any plumber/homeowner will be able to assess everything that is there. If aesthetics are a concern (one of the open design vessel sinks for example) run a small diameter pipe (1 1/4 brass drain for example) into the wall and towards the ceiling hooking it into either the main venting system or capping it with an AAV that can be accessed through a vent cover or something. I do wish they would make a better system but for now this has worked best for me.

Cheers,

Marlow

I had that problem. Took out the pop up drain and still had the problem. Then I drilled bigger holes in the flat screen drain. That solved the slow draining, and have no worry or expense of extra plumbing. Just remember to smooth out the drilling burs.

So was there a final solution to this problem? I am trying to determine if the new vessel sink I have just had installed, that of course has this issue, needs an AIR ADMITTANCE VALVE or should I drill the holes in the drain (would rather not do that).

Thanks and I appreciate an update.

Patrick

In an attempt to revive this thread, I'll post my thus-far futile attempts at solving the slow-drain problem with my darn vessel sink.

When I first installed the sink, I had a grid drain. It drained very slowly, but once in a while, if I agitate the drain by rubbing my fingers across the holes in the drain, some air bubble comes up, and all the water drains almost instantly. From this I concluded that it shouldn't be a clog in the pipes.

I was initially convinced that the problem is due to the lack of an air vent because of having no overflow, so I went to the Home Depot trying to find an AAV. They didn't seem to have one, and the plumbing guy there told me it had nothing to do with not having an overflow. He said it must be due to a clog, and suggested that I snake something through the pipes to clear the clog.

I wasn't sure I believe him, but I tried plungers and drano, and it didn't help. I'm not convinced that it is a clog, because otherwise why would it drain so quickly once in a while when the air gets out?

Then I also read this thread, about the problems with the grid drain, how it could be that the holes there are too small, and surface tension in the water is not permitting enough flow. I also read here, that kitchen sinks also don't have overflows, and they work just fine, and that makes sense to me. So, I replaced the grid drain with the pop-up, mushroom type drain.

That didn't solve the problem either. But it was a tiny bit better: as long as I don't let water to rise to the level where it covers up the holes in the drain, it drains fine. As soon as the water rises above the level where the holes are completely covered, the flow slows dramatically.

This leads me to believe that it is an air vent problem after all. What I don't understand is, the old question, why kitchen sinks work just fine without overflows? Is there something different there somehow?

I have a question pertaining to the subject of slow-draining vessel sinks without overflows.

Below are 2 photos of the vessel sink and the drain plumbing. The sink drains VERY slow. The owner is not certain that the grid drain was made for a vessel sink without an overflow. He wants to add some sort of air gap/vent to a portion of the drain line to help the water drain faster.
http://i288.photobucket.com/albums/ll175/realtymogul/1348ECheeryLynnRdbathroomphotos12_2.jpg
http://i288.photobucket.com/albums/ll175/realtymogul/1348ECheeryLynnRdbathroomphotos1-1.jpg

Any comments on whether a drain made specifically for this sink would help better than the air gap/vent?

Thanks!
:)

Good posts by all, and thanks for all your preliminary investigation and solutions. I am an engineer that deals with piping systems regularly, and recently purchased a new house with a sink that has this same problem - so I came looking for ideas also.

As stated by many, the problem is with the surface tension of the water acreoss the perforated plate, and the differential pressure above and below the plate. Inserting the straw illustrates this point. Additionally, you will notice that if you let the sink fill up to about the same height that the P-trap offers, it will all "flush" out and begin refilling... That is because the pressure above the plate has overcome the pressure below the plate. Therefore, the issue is not with the piping downstream of the trap.

Some comments on your suggestions, and then I'll offer mine...

An AAV is not the solution. You need to EXCLUDE pressure from the space between the sink and the P-trap, and an AAV lets air IN. The copper piping up the wall will work fine, but looks like a pain to install and does present a slight potential for hidden issues. Loosening the fitting below the sink sets you up for a potential water leak not seen into the cabinet below your sink. Drilling bigger holes in the perforated sink drain plate is not particularly aesthetically pleasing, and changing the drain out altogether is costly and a pain as well. And nobody can have a straw sticking out of their sink...

What you need in this case is a devisce that WILL let air out, but WON'T let water out. It is called an air trap, and is commonly used in industrial piping systems to exclude air from the system. I looked on the internet, and found a small and cheap one made by Honeywell (model EA122A1002) for about $30. I installed a PVC tee in the vertical drain line between the sink and the trap, then a PVC 90, then a 1-1/2x1/2 PVC bushing, then a 1/2x1/8 brass bushing. The air trap is mounted in a vertical position, and has a 1/8" male NPT connection. Don't forget to rotate the housing on the air trap once it is installed, to allow it to operate properly.

Works like a champ. I ordered the trap off the internet, and got the rest of the fittings at Lowe's (in one trip, no less!). Total installed cost was probably $40 or less for everything.

Hope this helps. It's amazing to me that the vessel sink manufacturers don't offer an easy, effective, and safe solution to this very common problem. Just about any do-it-yourselfer can do this one - no plumber required...

Mike,
Look in the upper left hand corner for the date. You're answering a thread that's been closed since 2008.
We thank you for the in put amd wish to welcome you to The Plumbing Page. Regards, Tom

Hello all. I have been battling this problem for the last two days, and I believe I've finally solved the problem. I tried the pop-up drain, and that still didn't allow enough air through the holes, so I tried one more time at Home Depot and found this: Dearborn Brass Two piece Less overflow chain and stopper drain. It's a 1-1/4" x 5" 20-Gauge C.O. Plug drain. It's part number 763K-1. Basically, it's a drain with no overflow holes, very down-and-dirty basic. Here it is: http://kscdirect.com/item/DEA%2B763K-1/DEARBORN%2BBRASS_CO%2BPLUG%2B1.25%2BX%2B5%2B2PC%25 2C%2BBUDGET%250A

It doesn't look like much, and it isn't, but the key is, it's got huge holes for the air to get in as the water goes down the drain. It's not pretty, but it does the job. Hope this helps.

Thanks for your update, Gerryfey...

I think Speedball might have the best idea, however, if you can live without a built in stopper (people have done it for years), that's the most expedient way.

Hey Bruce,
This thread has about run its course at over 20,000 hits. Bottom line? As long as they sell vessel sinks there will be drainage complaints, Cheers, Tom

From another web site: Drill a tiny, diagonal down (so water does not come out) hole as high as possible in the pvc down tube that connects to the drain tail piece.

Just tried it... problem solved!

Apologies if somewhere in the 40 answers, this was suggested.

WOW! Almost twenty one thousand hits on this thread. Why Steves solution will work why go to all that trouble when you can purchase drains made for vessel sinks, (see image)

Yo speedball1:

Would like to respectfully submit that the vanity/vessel sink I bought at Lowe's has the exact grid drain pictured on the right in your response. As you and others others have noted, the situation seems to be related to surface tension and water hardness, which conspire to not allow the draining water and escaping air to share the same small holes in the grid. While enlarging the holes, as Donald suggested, improves the situation, the very small air bleed, drilled diagonally downward, high on the pvc solved the problem for me (not my original idea, BTW). And simply removing a few hand tight connections was a very simple task... especially since I had taken the plumbing apart about a dozen times anyway, and was getting much better at it than I ever wanted to be :-). Plus, if it doesn't work, you are out a $4 piece of plumbing.

BTW, fifilyn's pics (thanks!) show a situation somewhat different than my own in that my drain tailpiepe has a much smaller diameter, allowing for a perhaps 1/8" space all the way around between the tailpipe and the pvc. Nonetheless, (referring to fifilyn's pic) I suspect a tiny air break hole drilled as I've described just below the threaded connector on the pvc (and angled down, to be extra safe) would allow air to vent through very small gap around the tail piece and the pvc. Also, since the tiny drilled hole will be above the bottom end of the metal tail piece, leakage through the hole would only occur if the trap is blocked. Of course, if the trap is blocked, the vessel sink, lacking an overflow is going to run over anyway. Finally, since the hole is above the trap, there would appear to be no code conflicts.

Best wishes and Happy Holidays!

Steve

What ever works for you Streve. Thanks for your input. And you have a happy holiday also. Tom

Here's the easy and cheap solution: get a Bulb Syringe Aspirator and keep it by the sink. When the sink drains slow then put it up against a drain hole and squeeze.
I agree with the surface tension explanation. I think this breaks up the tension somehow and initiates a whirlpool effect to drain the sink. If possible it also helps to adjust the faucet direction off center to encourage a whirlpool. You'll still need the syringe in many cases.
A Bulb Syringe Aspirator is available in the baby section of many supermarket stores for about $3.

Are we talking breast pumps here? Because if we are I have a much better place to place it over then a lavatory drain. Yours for giggles, Tom

Cute :) No, it's something used to clear a baby's nose. Amazon uses this exact terminology. After almost 3 years of struggling with this problem, and getting no help whatsoever from professionals, we discovered that blowing through a straw into the drain cleared the backup. The straw was a nuisance so we found this bulb worked too. We have 2 very different kinds of sinks (one deep, one shallow), both with grid drain and without overflow, and it works almost 100% of the time under all sorts of conditions. One plumbing store still insists we have a clog in the drain.

Hi Chef

I think most people coming to the plumbing page will be looking for a little bit more permanent solution, but thanks for posting your information.

When you finally get tired of using those aspirator syringes I would recommend that you consider purchasing a FLIP TOP VESSEL SINK DRAIN (see image). Over the last few years or so they really have worked out the kinks with these things. With the flip top drain you'll get a 50-50 mix of air and water and the sinks will drain perfectly. They are super easy to install... just need some plumber's putty is all!

Good luck!

Mark

PS The guy that thinks you still have a clogged drain is an idiot!

Thank you! I have never heard of these drains before. As common as this problem is, I'm surprised there is so little known about it.

Thank you! I have never heard of these drains before. As common as this problem is, I'm surprised there is so little known about it.
Well someone knows about it. We have had over twenty two thousand hits on this thread in the last six years. Regards, Tom

Thank you all, for posting your findings. I love the looks of my vessel sink, but not the draining issues. I am so thankful that I could learn from your experience, and will hopefully only have to fix the problem once as a result! Thanks, Kara

Thank you for posting, Kara. Glad if we helped!

Mark

Here is the cheapest solution that won't risk a leaking drain if the trap gets clogged down the road.

Fit the drain with a dishwasher drain tee, and attach flexible tubing and adapters as needed to run the tube above the top of the sink bowl. I can't believe I haven't seen anyone else doing this. See the attached pic http://i46.tinypic.com/69nslu.jpg (http://i46.tinypic.com/69nslu.jpg)

I have been running this vent for a month now, no problems.

The issue is air coming out by the way (not air admittance). Aerated water makes its way into the drain but the trap stops the air from continuing, this builds up a little pressure. Combine that pressure with the water surface tension on the grate of the drain and there's your slow drain.
You can always test this with a straw, just shove it down the drain when its acting slow.

I'll give you the "cheapest" solution award, Jdweeep, but not the best solution by any means! Here, they have really figured out vessel sink drains over the last few years and a simple swap over to a flip-top (see image), a push button pop-up (see image), or an umbrella vessel sink drain (see image) work great for these vessel sinks without overflows.

The same cannot be said for the standard grid type drain that comes with most vessel sinks!

Thanks for posting!

Mark

Tried that, She didn't like the look of it...