Random water connection

[CDubya]

I just took delivery of a 2021 XLR Nitro 321. We are out on the maiden voyage. While tinkering around with all the features I noticed a water connection directly on the frame under the kitchen slide. It's right above the waste connection. This connection is not label and is separate from the blank tank flush located in my passthrough area.

Anyone have any idea what this is for?

[NavyLCDR]

I just can't help thinking it is a sewer flush connection of some kind. Or maybe anti-freeze inlet for winterizing? I would connect a hose to it and listen for flow as you open the valve to the hose. If you hear water continue to flow it is flushing/filling something. If water flows only until it is pressurized, my guess would be anti-freeze connection which should be going to a closed valve on the inlet side of the water pump.

[Homebrew]

How many black tanks do you have, it might be a flush for the 2nd tank if you have a 2nd.
Very odd they drilled through the frame.

[NJKris]

Black tank is right there, gotta be a black tank flush. That is crazy how they went through frame and put it in a terribly inconvenient location though. I see the T off for gray tank, maybe you have a gray tank flush too?

[CDubya]

Well of all things it was the over flow for the fresh water tank. Figured it out this morning filling up my tanks before leaving for a boondocking trip.

Kinda silly that it is a female hose connection drilled through the frame.

Thanks for everyone's reply.

[NJKris]

That is weird. We all learned something new at RV University again today!

[cthelite]

Hey Cdubya... I just purchased a used 2021 back in May. Love it.... so far.
I have 2 drain valves that APPEAR! to be connected to fresh water [emoji98]. Even though 1 valve is black and 1 is white... they both HAD clear water in them. Do you know.... if these are fresh water? Do you have 2? Is there a gas tank drain??

[CDubya]

Originally Posted by cthelite

Hey Cdubya... I just purchased a used 2021 back in May. Love it.... so far.
I have 2 drain valves that APPEAR! to be connected to fresh water [emoji98]. Even though 1 valve is black and 1 is white... they both HAD clear water in them. Do you know.... if these are fresh water? Do you have 2? Is there a gas tank drain??
Attachment 277188

I have them both as well. Best I've been able to figure out is that there are two low spots in the fresh water tank that each needed their own drains.