Gray Tank Valves under sinks😳

[Strwbry]

I have a 2015 Passport Ultra Lite Travel Trailer….

Hello, I am super confused, any help is greatly appreciated. I have attached 3 pictures of what I have just learned is the gray tank water valve. The first 2 are of the kitchen the one that is closed and the 3rd picture is of the bathroom and is slightly unscrewed. Now I don’t have any smell like the thread I read but after reading that said thread, I ran looking to see what mine looked like. Now I need to know, do they have to be open and if so how far open or closed?If they are supposed to be open the kitchen one isn’t budging UGH lol

HELP🥳

[GlasNav]

Those are vacuum breaker vents, which allows the water to flow to the tank after the trap.

[Strwbry]

Hello! It’s me again lol

Should they be open or closed? The kitchen one looks like the previous owner sealed it but bathroom one is unscrewed a bit.

Thank you

[bobbecky]

They are properly called Air Admittance Valves, and there isn’t an On or Off position. They are a spring loaded valve that allows air into the drain but if working properly, will not allow air or gas to exit from the valve. They are used when a vent through the roof is not possible. https://www.amazon.com/Oatey-39012-A...s%2C356&sr=8-7

[chuckster57]

First two have thread sealant and the last one doesn't. Its fine either way.

[flybouy]

If the sink drains and there's no odor, then the AAV is working just fine.

[jsb5717]

Correct...no open or closed positions. There's nothing to do with them except replace them if you are getting gray tank odors. Otherwise they are working as designed and you just leave them alone.

[Strwbry]

Thank you so much. I read a thread about those and I got scared because I’m still learning a lot. Everyone on this forum has helped me understand things I didn't even know I had. You guys are great. Appreciate you.

[Stumpy75]

I know this is an old thread, but maybe this will help someone. I just had some odor under the kitchen sink and started looking at causes.

When I checked the AAV, it was barely screwed into the pipe(half turn??). Probably that way from the factory on my 2014 210TRS. I screwed it in more, and the smell is gone. Apparently the AAV is working, but the poor workmanship from 10 years ago finally reared it's smelly head!