Being cautious, I ordered new burner controls (infinity switches) for the front two burners. I installed them and was very happy with the results. The new controls allowed me to increase or decrease the amount of heat without what you might call thermal runaway (A sudden switch to full-on). Encouraged, I ordered two more burner controls and installed them for the back two burners. I have not yet tested them extensively, but I am confident that I now have four functioning burners.