if you had your trailer winterized and this is the first trip out, the values are closed going to the WH tank....... check the valves (X3)........
you can also turn your gas off and switch your WH over to electric to make sure it's not the gas you are having problems with....... search on "water heater" and "electric" on the forum; really good section about "Water Heaters" here; it's locked, but it has some really good info....
Day's Camped 2014 - 35 so far
2012 Rockwood Windjammer 2809W
2004 Dodge Ram 5.7L 4X4 Quad