A good source to help explain the water heater is Bill's document located here. You can view it in either pdf or word format.
http://www.trailmanorowners.com/foru...ead.php?t=2457
Another good source is Mike and Kelly's manual located here. It helps with all TrailManor owners and the processes involved with TrailManor campers. I printed this one out and put it in a binder, to keep in my trailer at all times.
http://www.trailmanorowners.com/foru...ead.php?t=2472