We have some sort of vent thing on our kitchen sink that has some awful smells coming out of it. The dishwasher drain attaches to it just below the sink at a T. On the other part of the T there is a black rubber hose running back down to the PVC pipe below the disposal and above the trap. Sometimes food from the disposal backs up into there, hence the smell. Anyway, I have tried pouring different cleaning products down it, and it still smells. It's clear of food now, but probably still has residue.

Before I try boiling water or really harsh chemicals, I want to check if that will ruin the hose. It's just a black rubber hose. Can I pour boiling water down it?

Also, could I pour a bunch of bleach into the dishwasher before it's next run, or would that ruin the dishwasher? The hose from the dishwasher is gray plastic and ribbed.

Thanks,

CM

CM,
What you have is called a branch tailpiece,(your tee) there is no vent.
You say, "On the other part of the T there is a black rubber hose running back down to the PVC pipe below the disposal and above the trap"
This is wrong. Someone connected a Fernco Neoprene Coupling when there should be a PVC raiser out of the trap connecting to the branch tailpiece with a PVC compression fitting. Romove the "J" bend and the rubber coupling and purchase a new "J" bend. Run a Pvc raiser out of the new trap up past the bottom of the B tailpiece. If the trap's 2" then make the PVC compression fitting 2" with a 1 1/2" gasket. Once you correct the faulty set up you'll have removed the smell. Regards, Tom


Question abt. "Odor from vent next to kitchen sink faucet" answer

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Thank you for your answer. I just have a few more questions. To be honest, a lot of your answer went right over my head.

Let me see if I understand. The black rubber hose shouldn't ever have been installed, it should be made of PVC. I need to remove the rubber hose and the J bend which I think is the trap. I need to get a new trap and a PVC raiser and put them in. (What is a raiser?) Why do I need a new trap again? The rubber hose is attached to a straight PVC piece above the trap.

Now, how do I connect the new PVC piece to the branch tailpiece and to the other end? I'm not sure what a compression fitting is. I've never bought or installed any pipes ever.

Thanks for your patience while you walk me through this.

Cara

Hi Cara,

I moved your answer from PM back to here. Much easier that way.
The "J"bend is the curvy part of the trap. The raiser is the PVC pipe that comes out of the trap and connects to the branch tail piece. And look at the image below to see what a compression fitting looks like.
It goes like this. You will need a "J" Bend in the correct size, (Since you failed to tell me I'm going to assume the pipe size is 2") A piece of 2"PVC pipe long enough to get a few inches up on the tail piece and a PVC 2X1 1/2" slip to compression fitting,( see image) also a small can of PVC cement and a can of PVC Primer. This repair will be very simple. Remove the rubber hose and the " slip to compression fitting,( see image) also a small can of PVC cement and a can of PVC Primer. This repair will be very simple. Remove the rubber hose and the " bend with the PVC raiser. Now glue the piece of PVcinto the bend remembering to prime both the pipe and the hub, also glue both the pip and the hub. Now prime and glue on the compression fitting. Remove the compression nut and gasket and slip them up on the tailpiece. Slip the PVC over the tail piece and tighten the trap nut. Now tighten the compression nut.
I have just walked you through the enrire process, step by step. Good luck, Tom

Hold it! Stop the presses! I think we have a MAJOR misunderstanding here. I think Cara was referring to a "Dishwasher air gap", which is required by some codes and acts as a "vacuum breaker" for the dishwasher.

I base this assumption on Cara's statement "We have some sort of vent thing on our kitchen sink that has some awful smells coming out of it." As you can see from the diagram below, an air gap device is installed in one of the holes in the sink's faucet deck; hence the appearance of being "on the sink", and not "under the sink".

Here's a diagram of the setup and how it works:
http://media.popularmechanics.com/im...hwasher-lg.jpg

Pictures of actual air gaps:
http://www.plumbingsupply.com/images/airgap-chrome.jpghttp://www.plumbingsupply.com/images/airgap-bone.jpghttp://www.plumbingsupply.com/images/airgap-black.jpg
Cara, does the thing you're talking about look similar to any of the pictures? If it does, forget about buying all those parts you and Tom discussed, and just follow the instructions in this article to clean the air gap thoroughly, and then see if it still smells.

Hey, Tom: If I'm wrong, then I'm terribly sorry for having doubted you; but if I'm right, well... I'm just glad I caught it before our friend Cara was put through a lot of unnecessary hassle. Still, it would be quite a record for me, to beat you at the plumbing game! :D

Cheers,
Moishe
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Moshie, I don't know what I'd do if I didn't have you around to keep me straight.
You are correct, it could be a air gap. I missed it because in our area we use drip loops instead of installing a air gap. However, It could still be a branch tee she was referring to.
Cara, I'm going to put up two images, one a air gap and the other a branch tailpiece. Please tell us which one you have. Again! Thanks for being so sharp Moshie. Tom

Thanks. This is exactly what I needed.

OMG it is 2015 and I'm having this problem and that article is no longer available. Can someone tell me how to clean that air vent?

This should help, after you watch some silly commercial. https://www.youtube.com/watch?v=rmG2JXQL858

4Cookie,

The best approach is to replace it with new Air Gap and discharge hose. Air Gaps run under $10.00 in Home Depot and a two foot piece of 7/8" hose will run you another $5.00 or so. You can do it yourself.

Milo