More information about the behavior would help. Does it attempt to light and fail? Can can hear the igniter clicking? Is there a smell of propane? Are there obstructions (wasp nest) in the burner tube? What more can you tell us?
In the Files section (look for the link in the thin brown ribbon above) are two manuals of the Suburban Water Heater that may help.
The
Suburban Water Heater Service & Training Manual
and the
Water Heater Troubleshooting - Suburban
P.S. Where in Olympia are you located?