James and Wanda: please check your FiberglassRV Private Messages, and the e-mail account which you registered with FiberglassRV. There are messages waiting for you in both.
I am surprised that no one else has pointed to the manual in the Document Center which directly answers the original request, and that no one bothered to do the Google search which would have found that manual:
"American Appliance water heater site:fiberglassrv.com"
1979 Boler B1700RGH, pulled by 2004 Toyota Sienna LE 2WD
Information is good. Lack of information is not so good, but misinformation is much worse. Check facts, and apply common sense liberally.