Domo

You've recognized the reality that all coaches need maintenance for the chassis and repair for the coach. And, hopefully you also know that floor plan might be the most crucial aspect of your search given the fine coaches in your list. I think we all believe that most "shortcomings", "errors in manufacturing or design" are overcome during the first few years of the original coach ownership <- as long as they performed those repairs and services. The right one is waiting for you...

Hmm, I wonder if a shop could disconnect both ends of the lines, cap one end of each and pressurize both lines. Let it sit for a day and then read the pressure to prove or disprove a line is leaking. Seems that might narrow your quest down... If you found a line was leaking you could simply abandon that line and run a new one rather than dig for access to the culprit (maybe abandon both lines is one was proved to be leaking).

Length varies from park to park - we always call to make sure our 36' will fit - AND, we've also learned that many of the folks on the "other end of the phone" do not understand how BIG a MH can be - plus, we've seen that the National and State parks had originally been designed for tents, then the sites had been expanded to accept small pull-behinds, then larger TTs and finally after very modest trimming of tree branches, motorhomes - But, even with the trimmed branches, the roads were not widened and straightened and now big 5'ers with giant trucks plus large MHs with toads and boats help to make access roads a great challenge. Please do not be daunted!!! We've learned to accept scratches on the MH 'cause heck, you can't seem them at night while you're busy looking at the stars holding your best friend's hand in a national or state forest/park.

Some water heaters do have a one-way check valve on the output side - I remember reading that some folks have had that valve stick in the closed position. Just thinking - that could give the symptoms OP is describing...

Departing Florida (home base) end of May and heading to cooler places for the summer with return to our sticks and bricks end of August - maybe into September. We're staying East of the Mississippi this trip and will meander our way through Nashville (we love Nashville - bring ear plugs if you go downtown) up to lower MI, over the Niagara Falls and then head South to meet up with some friends and eventually get home. We've got all the key reservations set up and had great luck booking at Army Corps of Engineers campgrounds as well as some military family camps. Can't wait - and NOPE, didn't let the pandemic issues slow us down... Looking forward to seeing everyone on the road!

I'm hoping OP is simply looking for personal recommendations... We've had great luck with our 2017 Jeep Cherokee Trailhawk (not a Grand Cherokee). It's the right size for the two of us, can be flat-towed (that year and other years did require a flat-tow wiring kit which our dealer installed for free). It can go pretty much anywhere a Jeep Wrangler can go - so off road, on road and it's cushy inside! We load the kayaks on top and but a bike rack on the rear 2" hitch for out ebikes, hook up to the MH and off we go!