Air Admittance Valve

[Jkwilson]

Getting the rig ready for spring, and one thing on my list was getting a spare air admittance valve.

I dug under my cabinets so I could see how much room there was before I shopped for a spare. But looking at it, I can’t tell if it’s male, female, threaded or glued.

I put some pressure on both the valve and the ring below and neither wants to turn. Didn’t want to break a pipe elsewhere so I refrained from channel locks without something else to back brace the pipe.

Anybody know how this valve is attached for sure so I don’t needlessly break something?

If removal is too involved, I may upgrade to avoid problems on a trip.

[Cate&Rob]

Hi John,

The AAV will be a male 1 1/2” pipe thread. There are direct replacements and better quality versions at most plumbing stores. It should be hand threaded into the female fitting which is glued to the end of the pipe. It is possible that some glue got into the threads during manufacturing.

Rob

[Jkwilson]

Hi John,

The AAV will be a male 1 1/2” pipe thread. There are direct replacements and better quality versions at most plumbing stores. It should be hand threaded into the female fitting which is glued to the end of the pipe. It is possible that some glue got into the threads during manufacturing.

Rob

Thanks Rob! That’s what I assumed, but I’d probably have been a really unhappy guy dropping wet coroplast if I broke pipes because I misunderstood the connection.

My brother-in-law is well known for torque testing threaded items. He actually got a left-handed shaft bolt to come out of the aluminum shaft by tightening it with a cheater pipe. Maybe I should say “the remains of the shaft”. Can’t tell you how many times he’s had to pay to have his “torque blindness” fixed by a pro.

[Jkwilson]

You were correct Rob. Not that I doubted you! Just a little more force than I was willing to blindly apply popped it loose

[boyscout]

You were correct Rob. Not that I doubted you! Just a little more force than I was willing to blindly apply popped it loose

This is a popular replacement for that valve. Costs several times what the junky ones cost but has a good reputation for reliability.

https://www.homedepot.com/p/STUDOR-1...0341/202275238

[Jkwilson]

This is a popular replacement for that valve. Costs several times what the junky ones cost but has a good reputation for reliability.

https://www.homedepot.com/p/STUDOR-1...0341/202275238

That’s the one I’m looking at.

[Jlawles2]

What's the difference between https://www.homedepot.com/p/STUDOR-1...0341/202275238 and https://www.homedepot.com/p/STUDOR-R...0353/203111264 other than the first is rated for 24 DFU vs 20 DFU. My guess would be since they are on single stack the smaller would be sufficient and as my plumbing is up against everything a better fit so as to not bend the stack and keep it under side pressure.

[howson]

What's the difference between https://www.homedepot.com/p/STUDOR-1...0341/202275238 and https://www.homedepot.com/p/STUDOR-R...0353/203111264 other than the first is rated for 24 DFU vs 20 DFU. My guess would be since they are on single stack the smaller would be sufficient and as my plumbing is up against everything a better fit so as to not bend the stack and keep it under side pressure.

After looking through the brochure, I agree. The Mini-Vent I literally just installed in the bathroom was tight (due to the replacement sink I installed). The Redi-Vent would have been easier to get in the pipe.

[howson]

I was at Lowe's today so picked up two of the Mini-Vents. Been meaning to replace the OEM valves for awhile...this thread finally pushed me to actually do it.

The upgrade is about as simple as it gets. In my 315RLTS there are two of the Air Admittance Valves (AAV). One under the kitchen sink and one under the bathroom sink. They unscrewed without too much fuss. I sealed the threads with MegaTape (instructions, which are attached to this thread, said not to use anything but tape) and reinstalled. As documented in thread 8, the bathroom was tight but manageable.

For those who need to see pics, here you go...

Under the Kitchen Sink. OEM on Left ("Before"), Studor Mini-Vent on Right ("After")


Pics 3, 4 and 5 show the R&J AAV and it's internals. Pic 5 shows that the kitchen AAV was accumulating "stuff". Pic 6 shows the packaged Studor Mini-Vent next to the R&J AAV.



Pic 7 shows how the once out of the package the 1 1/2" vent is revealed. Pic 8 is a side-by-side comparison.


As previously mentioned, I put MegaTape on the threads and installed.

[SolitudeAtLast]

Are ALL the AAV’s the same 1.5” male pipe size (kitchen, bath) ? What about the anti-siphon valve for the black tank flush line. Other posts have indicated it’s usually located behind the shower wall? What is a good anti-siphon valve for that?
Thanks, Doug

[Cate&Rob]

Are ALL the AAV’s the same 1.5” male pipe size (kitchen, bath, black tank vent line) ?
Thanks, Doug

Hi Doug,

All AAVs have this same thread size . . . (at least, all that I have encountered or heard about)

Rob

[howson]

What about the anti-siphon valve for the black tank flush line. Other posts have indicated it’s usually located behind the shower wall? What is a good anti-siphon valve for that?

The black tank's anti-siphon valve is a completely different component from the AAV.

B&B Molders is the OEM for that valve, the same OEM that makes the Nautilus Panel. In the Nautilus P1 Panel Information thread (Reference Material sub-forum of this channel) has a PDF with a parts list. B&B calls the part an Atmospheric Vacuum Breaker. Google the part # and name and you should be able to find a replacement.

[Jlawles2]

howson Howard, I think the instructions said not to use it, but I use the soft set sealant. https://www.homedepot.com/p/RectorSe...5631/100351066

[howson]

howson Howard, I think the instructions said not to use it, but I use the soft set sealant. https://www.homedepot.com/p/RectorSe...5631/100351066

Yep--per the instructions, no pipe dope. Just teflon tape.

[Yoda]

Getting the rig ready for spring, and one thing on my list was getting a spare air admittance valve.

I dug under my cabinets so I could see how much room there was before I shopped for a spare. But looking at it, I can’t tell if it’s male, female, threaded or glued.

I put some pressure on both the valve and the ring below and neither wants to turn. Didn’t want to break a pipe elsewhere so I refrained from channel locks without something else to back brace the pipe.

Anybody know how this valve is attached for sure so I don’t needlessly break something?

If removal is too involved, I may upgrade to avoid problems on a trip.

To prevent pipe breakage use 2 wrenches. Channel locks up top and a regular pipe wrench below (monkey wrench) used to hold the pipe and keep it from twisting when using the channel locks.
Keith