Tab400 Alde convectors removal and upgrade

ColinsTab400

Has anyone removed all the convectors in a 400?  I am interested since there is a way to avoid the corrosion issue, but it requires removal of all the convectors to "paint" the connection ends.    Thanks

Denny16

Getting to the rear convectors is easy, remove the rear bunk panels next to the back of the trailer, and you can see the convectors.  The front convector is accessible by removing the front cover under the dining table.  The issue is going to be getting access to the two convectors under the front side portholes and the convector under the galley, behind the bottom cabinets.  These convectors are installed before the outside wall panels are installed, once the sides are in, access is going to require disassembly of the inside panels.  The convector that is really hard to access to is under the shower pan floor!  Additionally, there is a hose to stainless pipe connection under the main door threshold, but it’s stainless steel, so not likely to corrode anyway. 

The only reports of corrosion on the Alde pipes seems to be in the TaBs built before 2018 and is a few 320s.  The TaB400 came out in 2018, and I have not seen any reports of issues with the Alde convectors in the 400s.  Keep the glycol transfer fluid changed, and change over to Rhomar and you should be good to go.  You can use the convector connection under the galley sink to see if there is an issue.  

Here is a photo of a 2018/2019 TaB 400, showing the galley convector location during the facotry build:

The galley convector is circled in red.  There is a plywood divider in front of this to create a back to the cabinet under the counter.  The right end of the convector is under the sink, and is accessible by removing the under sink shelf.
Cheers

db_cooper

Those  hoses that attach to the connector with a sharp bend are most prone.  If you can get eyes on the difficult to reach convectors you could skip those if they are a straight run.

ColinsTab400

This is a tremendous help!  Thank you!

rh5555

I'm just finishing up the Rhomar exchange on our 2020 TAB400.  While I was at it, I checked all the convectors (even the one under the shower).  They all showed some corrosion at the end of the connectors, some more than others.  @ColinsTab400: I'll do a full write-up when I've finished putting the TAB back together.  The corrosion problem isn't limited to

TABs built before 2018 and in a few 320s.

It just isn't as bad, yet!

bergger

Did you actually remove the tubes from the connectors to see the corrosion or was there simply visible bulges of the tubes at the connection  points? I did a visual check of all ours, 2021 400, last year and saw no signs of  any. I just looked for bulges and did not disconnect anything. I’ll do another inspection this spring when I dewinterize the trailer. 

rh5555

I removed all the convectors from the TAB. There wasn't obvious bulging and the corrosion was a lot less than I've seen elsewhere on this forum. 

This was the worst:

Most looked like this:

They all cleaned up pretty well:

I was still worried about the crease at one end of each convector shown above.  I ended up cutting them off with a chop saw.  Looked like a perfect place for crevice corrosion to get started.

rh5555

ColinsTab400 said:

Has anyone removed all the convectors in a 400?  I am interested since there is a way to avoid the corrosion issue, but it requires removal of all the convectors to "paint" the connection ends.    Thanks

What is your vintage of 400? 

Evidently some years had easier access to the convectors than others.  Accessing the front convector on my 2020 TAB was next to impossible as the cover's front and top were bonded together, so there was almost no access.

Access to the converter under the bathroom floor is impossible unless you have the Hepvo drain which can be removed to gain access.  I had already done this modification.

ColinsTab400

11/2018.  2019 version.  I haven’t done the drain mod