Five years ago I purchased a 36" 5 burner/grill stove with a self cleaning oven. Everything works fine, except that no matter how low the cooking temperature is the 2back burners look as if there is fried/dried grease a brownish color. They do not clean with cleanser, ammonia, or brillo without extraordinary scrubbing. I had the two burners replaced under my Sears maintenance contract, but I was informed that this is not a repaired problem. The grates were shiny black when new, but after several months of use they develop a grey-like caste. They have been replaced by the manager several times.