There is a lot of discussion on this site regarding the efficiency of absorption refrigerators. Our friend Bob Miller mentioned in another thread that a Dometic engineer told him that the refrigerators should work best on LP, followed by AC and then DC.
My Dometic RM-2193 has never worked on LP as well as on AC in hot weather, 80 degree F and above, despite my having cleaned the burner and the flue on a couple of occasions. I never cleaned the jet because it looked nice and shiny, and frankly it looked so fragile that I was afraid to pop it out. In addition, I have added ducting and a computer fan to improve air flow over the condenser fins and added insulation to the outside of the unit.
Looking on YouTube I found this short video on cleaning the burner: