if i'm not mistaken, a most tankless water heaters require 110v AC.
having read about any propane ones.
so, you'd have to have electric hookups. and having owned popups for 17 years, we never camped anywhere that had hookups.
personally, i would never have one of these. it limits where you can camp.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC