I just posted a question asking if anyone had added a Alde Flo to a 2018 TAB 400 and I saw your post from August.
"We have a 2018 TaB400 and are considering adding the aux Flo tank to our system, which requires the newer Alde 3020 heater, which we have. I did a lot of research into what was required to add the Flo tank. It ends up being a basic plumbing job, but requires space next to the Alde for the Flo tank, and plumbing the Flo in front of the main Alde unit."
I don't have the 3020 but would be prepared to change that out. did you eventually do this? Were there any issues? I am not a handyman so I would get it done for me ... any idea of the cost?
Richard of York