Originally Posted by 74Fox
The model of the water heater is: SW6, Suburban Direct Vent Gas Water Heater
Thanks 74Fox. There should be some more digits after the SW6, that will tell us a little more about your particular model (maybe a P or a PE perhaps). This info should be on a tag at the bottom right hand side of your water heater box (accessed from the outside of your trailer)
I just want to make sure of the exact model to narrow down the problems it could be with yours as Suburban makes a SW6 in a P, PR, PE, PER, D, DE, and DEM. All of these after letters tell us how your heater operates, and what to look for in the troubleshooting.
Here is a pdf file on the SW6 (and it's many models). Near the bottom of it are some troubleshooting guides, that are sorted by particular models (once you know your exact one).
I agree with others that it could be a clogged tube, or maybe a faulty gas control (which I assume you are turning the gas control valve to the on position after lighting the pilot light in the pilot position).