Raising Height of AAV

D107 · October 30

I thought this would be easy, but found that PVC piping does not come in the same varieties of connectors that brass or steel piping does. I need to raise this AAV 5-6 inches to get it above at least the sink drain. Very slow draining, crud climbing into AAV etc. Other thread on this wisely recommended a trial by raising with some kind of makeshift hose but I don't have anything 1.5" wide. What I need is an extension with 1.5" mail threads on bottom with 1.5" female threads on the top end for the AAV to screw into, but it may not exist. Trying to avoid PVC gluing.

I believe all these connections should have gaskets and thread seal tape, which I hope the original plumber installed; I'll have to check.

ethicalpaul · October 30

If you have very slow draining, that is a separate issue to be addressed—not the AAV's fault, right?

But to answer your question, you can get pvc adapters with threads at the big box stores, then weld the appropriate length of pipe between them to get the height you want, whether it's 1-1/4" or 1-1/2" or whatever you have there

such as this example from HD

mattmia2 · October 30

you can find an extension with compression fittings molded on both ends intended to be cut in to 2 extensions that is the right length and use that or you can use an extension and a compression to compression coupler or you can use a compression adapter, a piece of pvc pipe, and a npt adapter. The tubular fittings are the cheapest because you don't have to deal with pvc cement. You can get a huge assortment of plastic tubular fittings from supplyhouse.com or a real plumbing supply. You can also use metal tubular fittings or even galvanized fittings which might be cheaper when you factor in the pvc cement. Galvanized will last forever there because it never gets wet.

Larry Weingarten · October 30

Hi, Might you be able to make a tailpiece extension work for this? Or replace the "T" fitting with something you can put a vertical tailpiece on? 🤔

Yours, Larry

mattmia2 · October 30

https://forum.heatinghelp.com/discussion/comment/1817103#Comment_1817103

Actually you made me think of somethign else. I'd make sure there isn't a partition in that tee because it looks like a tee that is designed to connect 2 sink bowls together with a baffle to try to keep water draining from one bowl from splashing in to the other bowl.

DCContrarian · October 30

Everything from the wall is plumbed with tailpiece pipe, which is different from regular plumbing pipe. That Studor valve looks like it has regular 2" pipe thread, and the tee has an adapter built into it to go from tailpiece to 2" pipe thread. So what you want is a 2" male to female adapter.

The easiest way is going to be to build one out of a couple inches of 2" PVC pipe and a male and female adapter. I know you said you don't want to glue PVC but that's how it works.

The only alternative would be to see if you can find a taller tee and replace the one that's there.

hot_rod · November 1

That looks like a baffle tee that it is tied into. Used to connect two bowl sinks. that could be the slow drain issue. Take it apart and see what that tee looks like inside.

A rubber fernco coupling fits nicely also, easy to service.

DCContrarian · November 1

https://forum.heatinghelp.com/discussion/comment/1817108#Comment_1817108

I don't think it's a bowl tee, I think what we're looking at is a RectorSeal MagicTrap:

https://www.supplyhouse.com/Rectorseal-97402-Magic-Trap-Tubular-Fitting-w-Tee

mattmia2 · November 1

https://forum.heatinghelp.com/discussion/comment/1817473#Comment_1817473

One has to look inside and check.

D107 · November 1

I had showed the photos to the Home Depot guy—who seemed to know his plumbing—and he said that whoever did that work mixed up polypropylene and pvc piping. I'll try to get to this in the next week.

D107 · November 2

So the tee turns out to be an Oatey Tubular PP F-409 1.5inch Tee, apparently not a bowl tee. Didn't open it up, but Depot plumbing guy said the installed Tubular Tee would not have a partition or be for a double-sink. So then he found me a Oatey 16" 1.5' double-ended Extension Tube which I think will work. Tricky part will be measuring and where to cut.

mattmia2 · November 2

you also need a coupler if you're using that unless there is enough space to use it whole. you could rotate the tee and put the riser at an angle to fit it in.

D107 · November 2

No that piece is way too long. Rotating the tee to a 45 or 90 is a great idea—but the faucets might be in the way…..I could thread the bottom of the piece into the bottom nut, cut the piece at the right length then screw the vent into the other nut on top if I'm visualizing this correctly. If there was such a thing as an 8" extension I could get a female to female coupler at the top and screw one end of the coupler to the piece and then the vent into the other coupler end. Or this:

https://www.amazon.com/Plumb-PP812-15-Extension-Coupling-inlet/dp/B000KKUNQG?th=1

mattmia2 · November 2

there is a coupler that is 2 tubular compression fittings. you could also use a female mpt to tubular compression adapter

if you put it at an angle the studorvent still needs to be at the bottom of the counter, it can be more than a 45 but it needs to still be near the dripline of the fixture

ethicalpaul · November 3

it needs to still be near the dripline of the fixture

I think this is a common misconception. Oatey themselves say below, and show the device below the bottom of the sink:

D107 · November 3

@ethicalpaul Yes Oatey and other AAV makers give the impression that if you're 4" above the horizontal branch then you're good, but really that might only be good on a very large sink where the dripline is very low and within those four inches. Furthermore, on a slop sink for example I would think that the AAV should be much higher(?) than the dripline—a little higher than the top of the sink so when the sink fills with a washing machine cycle, the AAV will work however high the water level gets. In your photo example, I'm also not sure about that electrical outlet below the sink (?), even if it has a GFCI.

ethicalpaul · November 3

I guess if you think the manufacturer is lying and/or trying to set up their product to fail you can disbelieve them, but I doubt they want to do that. Oatey didn't give the impression, they clearly stated it.

Not really related, but are you concerned about the outlet below the sink in general, or in conjunction with an AAV? I would think that Oatey is familiar enough with the various codes not to put a violation example on their web site. I actually have this exact setup myself because my house has S traps and I have a garbage disposal.

leonz · November 3

I am going to suggest that you buy a drain blaster with a garden hose. The drain blaster is a heavy canvas balloon that inflates inside the steel pipe in the wall and when it become fully pressurized from the system pressure the valve opens and blasts the clog out. Remove the PVC pipe and fittings all the way back to the wall and insert the drain blaster there.

Connect it to a hot water tap to aid in dissolving the grease that will be in the pipe, if you cannot access a laundry sink with a hot water tap you can use cold water, you will want to run the cold water longer in that case.

I have used my drain blaster with hot water once in 7 years and I have not had a clogged bathroom sink drain since then.

D107 · November 3

@ethicalpaul I think I misunderstood your next to last comment. So you meant it's a misconception that the AAV needs to be near the dripline of the fixture. So following Oatey's guide—yes manufacturer would not intentionally set up their product to fail—there should be no benefit to me raising the AAV—which is what your very first post on this implied—that there was some other issue going on. Photo shows the basement waste line going into the branch (includes toilet and kitchen sink—both with no clogs). So I wouldn't have thought of the sink being clogged but I guess I have to consider that. I should point out that this is a tiny sink with a tiny drain, more like a bar sink. It appears that given the 1.5"+ drain size the drainage water seems to move consistently except when drain is an inch full where it stops for a few seconds, then bubbles, then drains fully. (And of course the drain cover has to be seated properly, and not set as a stopper.)

PC7060 · November 3

https://forum.heatinghelp.com/discussion/comment/1817839#Comment_1817839

the outlet is probably on a GFCI branch circuit.
Coincidentally, I’ve got almost that exact configuration on a kitchen prep sink.

Except my AAV Is higher. 😎

ethicalpaul · November 3

So following Oatey's guide—yes manufacturer would not intentionally set up their product to fail—there should be no benefit to me raising the AAV—which is what your very first post on this implied—that there was some other issue going on

I won't say there's NO benefit, but I would say that under normal operating conditions there probably isn't much if any benefit. Remember, the device has a check/float ball — one of its jobs is to allow air in, but not out. By not letting air out, it will tend to prevent water from rising up to it from the horizontal pipe— which makes me think water must have filled all the piping we see in your photo or just about, for some period of time.

In your case, you mentioned that the drain is slow ("very slow draining"), and we can see that the vent is fouled.

I think if you had a situation where there was a partial clog that was after the AAV, and you had a sink completely full of water and opened the drain, and the water sat there, there could be fouling of the vent like that.

But that's not normal, to have a slow drain like that, in my opinion. Good luck with finding the issue, it can be a real pain. I had a very slow bathroom sink drain in my last house, it turned out to be a ton of rust chunks had fallen down the stack and made a big pile that blocked the inlet into the stack that the sink used. That one took me forever to find because other than that it was clear all the way to the basement.

PC7060 · November 3

The sink I showed above had problem with very slow draining as well; however the dishwasher drained just fine (this was before the disposal was added). The problem was gunk (nature loves warm wet dark places) build up below the large strainer basket and above the dishwasher discharge connection. While you could remove basket and clean out the strainer area, the space captured bits that got by the strainer never got completely flushed out by the low flow faucet. I changed the drain and replaced the large strainer with a small disposal and no more problems.

Larry Weingarten · November 3

Hi, Regardless of what the manufacturer suggests, I like the AAV to be above the flood rim of the sink if possible as a fail-safe. That way there is essentially no possibility of water ever escaping from it. Imagine the condition of the rubber in it 100 years from now… Also, it it's put in an accessible place, it can be used as a cleanout too.

Meddlesomely yours, Larry 😜

ethicalpaul · November 3

How is under the sink not accessible? And what place above the rim of the sink is accessible? Do you make a door in your wall?

Larry Weingarten · November 3

Hi, I'm trying to envision running a snake down the pipe the AAV is attached to. Many AAVs likely doesn't have that sort of access. And about a door in the wall, yes, I've installed some access panels for AAVs. Can't do this for all of them as many people would rather look at a medicine cabinet than an access panel. 😏

Yours, Larry

JakeCK · November 4

Speaking of access panels for aav's:

They don't bother me. It serves a purpose.

Raising Height of AAV

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