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.

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Originally Posted by racroo

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.

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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.

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Originally Posted by racroo

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.

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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?

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Originally Posted by racroo

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?

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Tom posted a really good picture of the set-up in another thread.

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-po...in/search-html
To check it out.
Good luck, Tom

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Originally Posted by racroo

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.

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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

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Originally Posted by speedball1

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

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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?

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Originally Posted by racroo

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?

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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...p?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/onlinecatal...0102&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.