Kitchen sink doesn’t drain.

[Nvr2many]

2013 Sunset Trail Reserve 30RK. Rear kitchen.

I’m in North Dakota so I’ve been dealing with cold weather issues, but it’s in the 40s now and everything is thawed. I first ran DrainO thinking the clog was close. Didn’t work so I pulled everything apart under the sink. It was pretty clean and I cleaned the under sink pipe vent. Next I used a 25’ auger to snake as far as I could go. I’m assuming 25’ should get me to the grey tank but I haven’t dropped the underbelly so I’m not positive. When that didn’t work I hoped maybe the roof vent was frozen or clogged, but I drained the grey tank and if it was the vent, it should’ve pulled the sink down. Still no drainage though.

I’m at a loss. Short of pulling the underbelly, I don’t know what else to do. Maybe the clog is further than 25’, but it’s rare for solids to make it past the kitchen drain since it’s so small. I’m hoping there’s something I’m missing and don’t know about. The owner’s manual is very generic and doesn’t tell you anything of value.

Thanks for any help.

 

[mark5w]

Here's an article to maybe help you.

https://uniquecampingmarine.com/blogs/news/how-to-unfreeze-rv-pipes-and-tanks#:~:text=has%20not%20frozen.-,Wrap%20the%20lines%20with%20heating%20tape%20or%20heating%20cable%20and,thaw%20both%20tanks%20and%20pipes.

 

[Wingerdinger]

Many RVs sinks and tubs have what is called a 'HEPVO' valve, rather than a P-trap.
Look under the sink, and if you don't see the conventional double-loop piping of a P-trap, you have a HEPVO valve.
Both chemicals, and most certainly a snake WILL damage a HEPVO valve, and it will need to be replaced.
The proper way to check for a clog in either a P-Trap or a HEPVO valve is to remove them. They are easy to remove, usually without any tools. Just be sure to have a bucket under them to catch the water.
This should be the first thing you do when you have a slow drain.