Air Admittance Valve (AAV) Questions

markcee · 09-21-2020, 05:04 PM

I posted previously about one of my gray tanks running a bit sluggish when dumping. Some member posts pointed to a faulty AAV.

When I unscrewed the AAV I hear a rattling noise when I shake it. Is this the flapper mechanism acting as it should? Or does this indicate damage?

Since this issue began, we periodically smell a gray water odor under the sink, so just on general principle, I'm inclined to replace the AAV, but here is my latest conundrum: I easily unscrewed the AAV from the piping and my AAV has an inside thread. All AAV's I've seen online are an outside thread.....unless an adapter is included. However, these adapters, when in place, make the AAV appear to be the same general diameter from top to bottom. My AAV is definitely more narrow on the bottom (see pic below) with this adapter in place. In addition, there is no way I can remove the threaded part on my AAV - I can spin it (with difficulty) but it does not appear to come off. My AAV is an Ayrlett brand, and I'm pretty sure it is the A6-T (threaded adapter model).

So, I'm assuming this is pretty low end part and I'm not opposed to an upgrade (if you think it's worth it). If so, I'd appreciate someone pointing me in the right direction to a better AAV that will fit this application, and explaining what I'm missing here with regard to the thread gender!

Thanks

NH_Bulldog · 09-21-2020, 05:12 PM

It should rattle if you shake it, but shouldn’t be floppy. The flap is supposed to allow air to get sucked in when needed, but the spring should reseat the flap to prevent gas escaping. To say these things are cheap is being generous. If you are going to replace it, I would suggest a Studor Mini Vent. They are about $25, but well worth it in my opinion.

Javi · 09-21-2020, 05:18 PM

Take it to Home Depot or another plumbing supply and they will help you get what you need, but don't cheap out spend the money to get a good one.. the one I used in my last trailer was $25

markcee · 09-21-2020, 05:23 PM

Thanks guys....I do want a better option, just confused by the thread issue and was hoping to be able to pick something up online. Bringing the trailer home next weekend so worst case I'll pop it off and head to the store for a suitable replacement.

Side note: went to check the bathroom valve for comparison's sake....that one is totally wedged up against the underside of the sink....lol. If that one needs replacement, I have a little more work on my hands!

CedarCreekWoody · 09-21-2020, 05:45 PM

They come in both thread styles.

markcee · 09-21-2020, 05:57 PM

Quote:

Originally Posted by CedarCreekWoody

They come in both thread styles.

I'm sure...but I sure can't find anything like what I have, online. Compare my pic and give it a go. I'd be grateful if you find one. The only representations of an inside thread AAV are the threaded adapter models. An 'adapter' to me means that it can be used as needed, and therefore is removeable. Mine cannot be removed, so I'm not 100% sure that's what I have. I'm guessing that my pipe connection is likely a 1.5", (should have measured prior to leaving the site for the week) and the only inside thread AAV fittings I find online look to be 2"....which is accomplished by the addition of the adapter.

bobbecky · 09-21-2020, 07:17 PM

You can cut off the threaded adapter already installed and glue on the adapter that will work with the replacement valve. No need to stress about having to use whatever adapter was installed, just get the parts that will make the new valve work.

rhagfo · 09-21-2020, 10:03 PM

The air admittance valve should have no effect on a tanks ablity to drain. Did you verify that the roof vent for that tank is clear? I have two grey tanks front one is for shower and vanity, it has a 3” drain valve, drains like a banshee.
The second grey is the galley, it has a 1-1/2” drain valve it drains noticeably slower. Do you know the size of the two valves?

NH_Bulldog · 09-22-2020, 03:22 AM

Quote:

Originally Posted by rhagfo

The air admittance valve should have no effect on a tanks a little to drain. Did you verify that the roof vent for that tank is clear? I have to grey tanks front one is for shower and vanity, it has a 3” drain valve, drains like a banshee.
The second grey is the galley, it has a 1-1/2” drain valve it drains noticeably slower. Do you know the size of the two valves?

To build on this, the AAV’s allow water to freely drain down the sinks and tub into the grey water tank. The roof vent is really what helps the tank to drain when the dump valve is opened. The grey tank roof vent on mine is located under the refrigerator roof vent shroud.

markcee · 09-22-2020, 04:02 AM

Thanks all...I'll give the roof vent a check this weekend. As always, appreciate the replies!

wiredgeorge · 09-22-2020, 04:39 AM

Some air admittance valves are better than others. Oatey and Studor are better quality and allow less stink than junk valves used in a camper. Both will probably be available at a home improvement store. Lack of flow will be your tank vent and these have no flappers if memory serves. They can get obstructed.

Javi · 09-22-2020, 04:47 AM

Sorry folks the Island or galley tank doesn't have a roof vent in my trailer... The Grey and Black tanks do.. That valve is the vent for my last two trailers... both with opposing slides... Oh... and if the fridge is in a slide there won't be a roof vent for the fridge either..

Here is a blast from the past... https://www.keystoneforums.com/forum...ad.php?t=22383

wiredgeorge · 09-22-2020, 04:56 AM

The OP started the thread by stating a tank he was dumping was sluggish. Doesn't have anything to do with the air admittance valve but he said he got some stink under the sink, if memory serves. There are better quality air admittance valves; we have used Oatey in our home as the ones originally in place were junk and odors were present. The fact that he has a sluggish tank says the tank vent may be the culprit.

Javi · 09-22-2020, 05:01 AM

Quote:

Originally Posted by wiredgeorge

The OP started the thread by stating a tank he was dumping was sluggish. Doesn't have anything to do with the air admittance valve but he said he got some stink under the sink, if memory serves. There are better quality air admittance valves; we have used Oatey in our home as the ones originally in place were junk and odors were present. The fact that he has a sluggish tank says the tank vent may be the culprit.

Depends on the configuration of the trailer but again.. there is no roof vent for many galley tanks...

SummitPond · 09-22-2020, 05:06 AM

Quote:

Originally Posted by NH_Bulldog

It should rattle if you shake it, but shouldn’t be floppy. The flap is supposed to allow air to get sucked in when needed, but the spring should reseat the flap to prevent gas escaping. To say these things are cheap is being generous. If you are going to replace it, I would suggest a Studor Mini Vent. They are about $25, but well worth it in my opinion.

^^^ to a Studor valve. We've had one in our S&B kitchen sink/dishwasher drain line for going on 20 years and it has worked like a champ.

rhagfo · 09-22-2020, 05:09 AM

Quote:

Originally Posted by Javi

Depends on the configuration of the trailer but again.. there is no roof vent for many galley tanks...

I would double check that, needs to be vented someway, may not be noticeable.

travelin texans · 09-22-2020, 08:35 AM

Quote:

Originally Posted by markcee

Thanks all...I'll give the roof vent a check this weekend. As always, appreciate the replies!

Quote:

Originally Posted by rhagfo

I would double check that, needs to be vented someway, may not be noticeable.

As Javi has stated already, at least twice, the AAV IS the tank vent, there's NO ROOF VENT.
My last 2 5th wheels the galley had NO roof vent as the sinks were in the islands.

CedarCreekWoody · 09-22-2020, 08:58 AM

The vent they are referring to is the tank vent, not the sink vent. The AAV is the sink vent, as you have stated.

Javi · 09-22-2020, 09:20 AM

Quote:

Originally Posted by CedarCreekWoody

The vent they are referring to is the tank vent, not the sink vent. The AAV is the sink vent, as you have stated.

It is also the galley tank vent... at least in many cases like my current and last 5th wheels.. Usually if the kitchen sink/sinks are in an island and the fridge and stove are in a slide the vent IS the AAV ...

Why is this so difficult to fathom ????

markcee · 09-22-2020, 10:00 AM

Quote:

Originally Posted by Javi

It is also the galley tank vent... at least in many cases like my current and last 5th wheels.. Usually if the kitchen sink/sinks are in an island and the fridge and stove are in a slide the vent IS the AAV ...

Why is this so difficult to fathom ????

OK, lots of back and forth here..

I do have an island kitchen with double sink. I also have opposing slides and one of the slides does contain the fridge.

So....I am correct in assuming no need to jump on the roof and check for a vent, my AAV is the vent as Javi has stated?

You may also like: