What Is This Drain???

[NVRQUIT]

Can anybody tell me what this black drain below my 2021 Airstream Classic is connected to? It caused all that mess below and has been draining like that for several days (that I know of). I've owned this trailer for all of seven days. The bucket is directly below the white Alde drain that I performed today by flipping the yellow valve per the manual. I can't seem to find out though what that black drain is connected to? Thanks.

[OTRA15]

Welcome to the forum!

What else do your owner's and Alda manuals say about the system draining under certain running conditions?

Have you been running the heat a lot there in Colorado? If not, is your trailer [incl. the Alda system] thoroughly winterized? [water off etc.]

FYI there is a sub-forum for your model, with many knowledgeable folks:

https://www.airforums.com/forums/f540/

It might also be a good idea to call your dealer and sales person ASAP IMO.

Good luck,

[NVRQUIT]

Thank you for your reply. I'm currently getting to the bottom of it. The trailer has been fully winterized (after the event occurred). As part of that process, and flipping of the two Alde yellow valves, water did drain but not out of that black tube (rather the smaller white tube right by it...thus water heater related and not furnace (glycol)). I ran across another post who said the black tube has a clamp and brass plug. I don't think mine had that (perhaps it came off in transit). I will be confirming this tomorrow as well as talking with Alde. In studying the manuals and reading a ton of forum posts, I believe I am close to the solution. I will post a detailed solution once I confirm it so as to help others who might come across this problem too.

[OTRA15]

Thanks for the update . . . good luck!