Finally got around to digging into the gas works... Took the windscreen off first and there was a good size mud dauber nest in there. Got rid of that and tried to light it again. No joy. BTW, also checked the fuse on the control board and it was oik.
Next thing was to disassemble the burner, et al. Cleaned out the orifice and burner tube with alcohol and blew everything out with compressed air. Put it all back together and it worked first try. Nothing LOOKED overly dirty, but it must have been enough to keep it from firing.
Thanks to all for the help. We're good to go now.
Tom, Joyce, Faith & Ben
2005 Rockwood 2601 Ultralite
99 GMC Sierra SLE 5.3