I thought I'd report back on progress here, but unfortunately I don't have a solution. I went back to the coach armed with tools and a couple new filters with the intent of starting with a new filter just because. Just for the heck of it, when I got there, I hit the diesel burner button and well, it fired right up. I ran it for about an hour, shut it down and changed the filter. After one cycle to purge the air, it again, fired right up. It is a little stinky so I'm going to order a new nozzle and replace it, as well as a burner chamber clean, next time I'm at the coach. Again, thanks for all the help here and hopefully the issue doesn't come back.