Originally Posted by rwnash
It does not appear that there is any support on the underside of the heater- it "hangs" on the outside shell. Is this correct? A friend as a similar unit in his much newer trailer and there is a simple support from the floor under the heater. I am now thinking that the rough road caused the heater to move and the rigid copper piping caused the corroded threads to fail.
I just recently noticed this on my trailer. when I had some other things apart, I got a new view of the tank that I hadn't seen before, and I noticed that there was some blocking underneath it. not much...just a couple of pieces of 1x4. hadn't seen it before because the base of the heater in the front, where one would access the plumbing and/or bypass valves, is concealed by a hot-air duct from the furnace.
I would say that you are probably correct in your damage assesment. there wouldn't be much to support this big heavy box otherwise, and there'd be quite a bit of stress on the plumbing.
Personally, I'd replace with a unit of the same dimensions. 6 gallons of hot water is small enough...3 would be hardly worth having. not to mention, the "bolt-in" nature of the repair. The modifications that would be required for a different sized heater could be extensive. I've only heard of 2 sizes, anyway...6 and 10 gallon. There is such a thing as a "tankless" water heater for rv's, but they require a "10 gallon" hole, and are very expensive, but they give unlimited hot water, with no tank.