Flooded SOB

[Arcticdude]

Urnie,
Your electric element should be good. I found the service manual and saw that the element is in the antifreeze side of things and not the fresh water side. At least that's one less thing to fix!
I'll be at my rig this weekend, and will take a look at the fittings. I don't remember them being plastic, but will try to confirm. I got an "installation kit" from Roger Berke when I replaced my unit many years ago that had all the fittings I needed to completely swap one out.

In case you don't have it, here's where you'll find all the manuals: http://www.aquahot.com/library.aspx The AHE-100 series cover the 431/12 units we have. The installation manual has some tips for using pex.