Alde Drain Valve

markc12v30

I have a new 2024 Tab 400 and am trying to winterize.  The manual states to drain

"c. Hot water tank & FLOW drains.  Yellow Alde drain valve. Vertical position is open...."

For the life of me I can't find this Yellow Drain Valve.  Any help out there?  Many thanks.

pthomas745

The Famous Yellow Flapper Valves ( you have two, one for the Flow) are in the Alde compartment very close to the Alde.  You can see pictures and descriptions in this post.  Ask questions, plenty of info and experience on how to winterize with the Nautilus setup.

The thread explains what the Yellow Flapper Does.

https://tab-rv.vanillacommunity.com/discussion/17348/alde-gushing-water-from-drain-underneath

MuttonChops

markc12v30 said:
. . . 2024 Tab 400
. . .  Yellow Alde drain valve. Vertical position is open....
For the life of me I can't find this Yellow Drain Valve.

Hear You.  It is amazing with all of the forum/Facebook Group posts there are no good reference pictures of the Yellow Value Locations in the model-400.  Even the nüCamp winterize video only references one Yellow Valve location . . . now not all 400's were built with the extra hot water Flow 'tank'** and while Alde literature states the Flow should have it's own Yellow Valve it is not clear that all 400 rigs that have the Flow do indeed have two Yellow valves.  It gets confusing and each owner must investigate their rig to know what is what . . . .

This nüCamp Video briefly shows the location of the primary, Boiler, Yellow Valve and also covers the how to set/use the Nautilus System while winterizing.
nüCamp Support Newer 400 Winterize

If your rig has a Alde Flow System Yellow Valve it will most likely be located near the Alde propane exhaust vent/piping as shown in this image
- - - compiled from different thread images - - -

Footnote:
** the Flow Tank/Unit is installed on the cold water line before the Alde Boiler, it is not a tank. It is a heat exchanger that uses the very hot water exiting the boiler to pre-heat the incoming cold water.  That way the Boiler does not have to work as hard heating 'new' water to it's pre-set temperature.  My 320S does not have a Flow Unit; my guess is that having a Flow Unit would extend the volume of hot/warm water and perhaps reduce the colder water shock when taking Navy Showers . . .
it is not intended to be a continuous hot water source like a house Hot Water Heater.

Binghi

The yellow relief/drain valves are located on the floor of the utility compartment underneath the head end of the bed.

MuttonChops

Binghi said:
The yellow relief/drain valves are located on the floor of the utility compartment underneath the head end of the bed.

However, once again no Picture . . just words . . .

markc12v30

Thank you for the comments.  I will look again under the bed for them. That portion of the Tab is inside and warm, but I guess it is important to drain those lines and replace them with anti freeze because they connect with outside parts of the system.  

Sharon_is_SAM

@MuttonChops - Here are some photos from 2019, so a 2018 or 2019 400 model.  These were accessed from the outside cubby.

markc12v30

Excellent pictures....worth a thousand words as they say.  But alas, the 2024 model is different.  We are having a spell of warm weather so I will be searching again day after Christmas for the elusive yellow valves.

pthomas745

@markc12v30 they are down there!

This is a photo of a 2021 400, which shows the yellow valve right next to the main Alde unit. In theory, there is another in the vicinity of the Alde Flow unit, toward the bottom of the photo.

The new Nautilus panels tends to obscure the yellow valve, since all of the plumbing type operations (winterizing, sanitizing, draining, etc) are now accessible from outside the trailer. To make it even more obscure, getting to the valves in a 400 is even harder these days.  Another Tab Yoga exercise.

And, to add a little more: apparently, in the newer 320 CS models, the Alde is even a bit farther back, which obscures the Yellow Valve even more for those models.

Binghi

However, once again no Picture . . just words 

If you pull the designated bed panel and examine the compartment floor, you will see the two valves (at least in the 2021 400). You might have to crane your head a bit, but you will see them. No photos necessary.

markc12v30

OK.  Wonderful.  I will crane my head a little and find them.  Question:  Since I have already winterized shall I now open them up?  

pthomas745

If you didn't open them before, they probably have some water left in them.  If you leave the Nautilus in the "Winterizing" setting you can open the valves, take out what little water remains, and it should be fine.  If you open the Yellow valves and antifreeze comes out, your Nautilus valves were not in the proper position when you added the antifreeze.

Antifreeze in the Alde tank is not a problem if you are sure that you are not going to use the Alde while winterized. 

You may not find much water in the Alde tank after opening the cold water low point drain.  The Alde hot water tank is also drained partially from that valve.