The problem that exists is that mounting only to the wall and allowing it to flex up and down caused the tank assembly to actually bend the flange which is mounted to the wall allowing the lower outlet fitting to hit the floor.
The Atwood installation manual advises to mount also with under support to keep this from happening.
The trailer is only 18mo's. old and maybe 600-800 miles towed to date.
Has any body seen this?
I recently was supprised when I hooked up and turned the parks water hook up on, I found a steady water leak and traced it to the water heater.
It apears that when the trailer was manufactured and the waater heater was mounted, It mounts primarally to the wall and no real support under the tank assembly. After driving for a few trips, the lower fitting where it is welded to the tank had been bouncing on the floor of the trailer causing it to fracture at the weld.
I did find a 1"x2" block mounted with 1 screw to the floor below the tank. This block seemed to have worked loose and pivoted away from under the tank.
I contacted a local R.V repair shop and was advised this is hugely common.
I hope anybody else to inspect your coach before this happens to you.