Gray tank pressure

[Rackg50]

I have a 2022 36V11, we have noticed that we have a smell coming from the island sink.
We have also had issues with the sink not draining.
I recently loosened the vent valve under the sink. When I loosened it it was a big bust of pressure shot out through the vent and the small. The sink did drain after loosening the vent.
Does anyone have this problem or a suggestion?
Can I get Alliance to weigh in on a cause of the pressure build up on the kitchen gray tank?

 

[njolin]

Did you ever figure this out? Just encountered the same thing in our 36v11. Thanks!

 

[Grassjohn]

Sounds like a bad air admittance valve. A description is here: https://www.oatey.com/faqs-blog-vid...t=It must be located a,air to enter the valve.

 

[njolin]

Sounds like a bad air admittance valve. A description is here: https://www.oatey.com/faqs-blog-videos-case-studies/blog/how-install-air-admittance-valve#:~:text=AAV location&text=It must be located a,air to enter the valve.

Thanks, that's what I thought as well, but I was curious, if there were no other vents for that grey tank, would that mean the pressure in the tank would have to be released into the cabin?

 

[BryanValRox]

Thanks, that's what I thought as well, but I was curious, if there were no other vents for that grey tank, would that mean the pressure in the tank would have to be released into the cabin?

Hello njolin,
Wondering if this might be useful to you.

Tech Tip: Fresh Coach (Keep Your Coach Smelling Fresh) | Alliance RV

Suggestions on areas to inspect and methods to eliminate holding tank odors inside the coach. Version: 9.1.22

alliancerv.com

 

[njolin]

Hello njolin,
Wondering if this might be useful to you.

Tech Tip: Fresh Coach (Keep Your Coach Smelling Fresh) | Alliance RV

Suggestions on areas to inspect and methods to eliminate holding tank odors inside the coach. Version: 9.1.22

alliancerv.com

Thanks! That is helpful. Our problem seemed very much like the OP. Sink wouldn't drain, but I just emptied the tank. I unscrewed the air admittance valve and it was really under pressure. Pressure relieved and the sink drained. This led me to believe that the tank either didn't have a vent going to the roof, or it was somehow blocked. I didn't see any evidence of a blocked vent, but did find this post

In a different post, someone mentioned that the 36v11 had a grey tank just for the galley. That pic seems to be different, but perhaps I'll have to ask Valor for the blueprints.