Just wanted to say THANKS, for this forum, and all the tips on it.
By reading it, I figured out that the reason my hot water heater wouldn't work this last weekend, the first trip in a year or more, was because one of the winterizing valves was turned in the wrong position.
I also found out that the heater has an electric mode, which I never knew. Of course, the dealer never mentioned it when I bought the trailer three years ago.
So once again, THANK YOU SO MUCH to the fine experts on this forum for your great advice.