I just bought and installed a couple 'modern' styles sink that are extremely shallow and have no overflow receptacle. Consequently I chose a drain flange that does not have the ability to be pluged, it has merely a grill of 1/4" sized holes.

The problem I'm having is that there is an air lock created in the pipe before the trap causing the sink to drain very slowly.

Can anyone suggest a solution? Has anyone seen a style of drain flange that would allow air to escape while allowing water to pass around it AND also does not provide the ability to plug the drain. I'm thinking it might look like a tube within a tube.

I've also thought about using a dishwasher air gap on the lavatory counter, but I would prefer not to do that for aesthetic reasons...

Jason

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Originally Posted by tanman

I just bought and installed a couple 'modern' styles sink that are extremely shallow and have no overflow recepticle. Consequently I chose a drain flange that does not have the ability to be pluged, it has merely a grill of 1/4" sized holes.

The problem I'm having is that there is an air lock created in the pipe before the trap causing the sink to drain very slowly.

Can anyone suggest a solution? Has anyone seen a style of drain flange that would allow air to escape while allowing water to pass around it AND also does not provide the ability to plug the drain. I'm thinking it might look like a tube within a tube.

I've also thought about using a dishwasher air gap on the lavatory counter, but I would prefer not to do that for aesthetic reasons...

jason

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Hi Jason,

All lavatorys drain the same way, by gravity, and the overflow doesn't break a airlock. Both the drain and the overflow are on the same level so the basin's vented by the drain hole as it drains down the tail piece into the trap. Of course the grill with the 14" openings chokes the flow down some and the shallow basin doesn't hold enough water to give it much head pressure when it drains so that might just be the nature of the beast.
Or there could be a partial blockage in the drain line. In any respect since water seeks its own level and the water draining in will displace the trap seal by gravity feed I seriously doubt that you have a drainage air lock. Think about it? If you did have one you would see bubbles coming up past the drain grill to allow the water to drain. My advice? Look else where, the grill, a partial blockage but certainly not a air lock. Good luck, Tom

Here is a test that I tried which is why I thought there might be an elegant solution.

I inserted a straw into one of the 1/4" holes and the sink drained as fast as the water poured into it. Without the straw, I can see what seems to be a 1.5" diameter air bubble that is almost creating a seal beneath the grate.

It's almost like the holes are just the perfect size to resist the air bubbles trying to rise and also carry the weight of shallow pressure provided by the sink.

Would an air gap fix this? Or would the air still try to rise at the grate since it will be higher than the stubout for the airgap?

Jason

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Originally Posted by tanman

Here is a test that I tried which is why I thought there might be an elegant solution.

I inserted a straw into one of the 1/4" holes and the sink drained as fast as the water poured into it. Without the straw, I can see what seems to be a 1.5" diameter air bubble that is almost creating a seal beneath the grate.

It's almost like the holes are just the perfect size to resist the air bubbles trying to rise and also carry the weight of shallow pressure provided by the sink.

Would an air gap fix this? Or would the air still try to rise at the grate since it will be higher than the stubout for the airgap?

jason

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Are you saying that your grill is causing a air lock by constricting the airflow and causing a 1 1/2" bubble to form below the grill and above the trap seal? And by putting a straw through a 14" hole in the grill and into that 1 1/2" bubble you broke the air lock? I understand what you're saying and the way you explain it I guess it could happen that way but why would the manufacture put a item with such a design flaw out on the market? Hane you contacted the manufacture and asked him about this? And since, surely, you aren't the first one with this problem why hasn't a drain been offered that gets around this problem? Have you tried removing the grill? Would a replacement grill solve the problem? Iadmit in all my years I've never ran into a problem such as yours. Please keep me infomed. Trgards, Tom

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Originally Posted by speedball1

Are you saying that your grill is causing a air lock by constricting the airflow and causing a 1 1/2" bubble to form below the grill and above the trap seal? And by putting a straw through a 14" hole in the grill and into that 1 1/2" bubble you broke the air lock?

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Yes I think so.

The sink and the drain flange are not a matched product. They're from different manufacturers and I think they just don't work well together. I guess I'll try to find a different drain assembly.

Jason

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Originally Posted by tanman

Yes I think so.

The sink and the drain flange are not a matched product. They're from different manufacturers and I think they just don't work well together. I guess I'll try to find a different drain assembly.

jason

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Good morning Jason,

All of which goes to show, You're never to old to learn. Your problem's a new one on me. Because water's heavier then air every lavatory drain has pushed the air trapped in the tail piece back up and out of the drain. If I had to guess the drain that you installed prevents that from happening and the remaining water in the basin then starts to act as a seal. I've been a plumber for over 50 years and I don't get too many new problems that I haven't faced before at one time or another. This ones a "dilly"!! Thanks for including me in it. Please keep me in the loop and let me know how the new drain works out.
Regards, Tom

I've found another fellow with a similar problem, though he is struggling with a different 'designer' drain assembly. Here's his link...

http://www.aidtopia.com/nonfiction/kohler.html


This is the drain flange I have...

http://www.homecenter.com/product_de...GCID=C3030x111

Jason

Quote:

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Originally Posted by tanman

I've found another fellow with a similar problem, though he is stuggling with a different 'designer' drain assembly. Here's his link...

http://www.aidtopia.com/nonfiction/kohler.html


This is the drain flange I have....

http://www.homecenter.com/product_de...GCID=C3030x111

jason

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You have gave me a link that features 71 lavatory drains from all different manufactures. What's the brand and model # of your drain? Regards, Tom

That's weird, for me the link points to a specific page. Anyway here is the model number

Price Pfister 47 series Drain Polished Chrome Model 47-9GSC

Here is a picture.

And here's the sink...

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Originally Posted by tanman

Here is a picture.

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Can you give me a picture of the underside of your lavatory and the drain connection. I notice that your drain has a opening in the side what stops it from leaking. Have you considered drilling a small 1/8th inch hold in the drain to vent it? Or wouldn't that be applicable ? It seems like you're not the only one complaining. Cheers, Tom

Hi Jason,

Did you have any luck resolving your drain problem? I am having the same issue with another flat, no overflow sink (Kohler Purist Wading Basin K2314). I am using Kohler's recommended drain (K-7715) and it still takes forever to drain. Kohler Technical Service basically says that that's the way the drain works and that there is nothing they can do about it.

I inserted a straw as you suggested and that makes it work much better. My plumber is suggesting drilling a hole on the drain to add a vent, but that makes me a bit nervous.

Thanks for any input.

Well if anyone is still following this thread here is a solution that I've settled on.

Leave the lock nut off the tail pipe. Simply let the tail pipe of the drain flange rest an inch or two inside the 1.5 drain coupling, but don't tighten the lock nut. This allows for enough air to escape so the weight of the water above will break the surface tension. Of course, if you have a slow drain caused by a partial clog, and the water rises in the drain pipe past the coupling, the water will be emptying under the sink. I have a small bucket hanging under the p-trap to catch this problem before I do, but in two weeks I haven't had any water seeping out of the joint.

A completely foolproof way would be to use a dishwasher stubout on the drain and run a hose to the surface of your counter. There you could install a nice looking chrome plated airgap vent. This way you would know the drain is clogged before it does any damage below. The only draw back with this is the extra clutter on your counter top.

Drilling a hole would also work but you may still want to have a small bucket to catch the trickle of water if there is any.

Btw, I'm not a plumber. And I don't know what the code would have to say about any of this...

Goodluck.
Jason

I like this solution. Sinple yet effective.
A completely foolproof way would be to use a dishwasher stubout, (branch tailpiece) on the drain and run a hose to the surface of your counter. There you could install a nice looking chrome plated airgap vent. This way you would know the drain is clogged before it does any damage below. The only draw back with this is the extra clutter on your counter top.
That may be your best bet to break vacume. Tom