Report "Burner valves stuck and will not turn. First the knob for bottom left burner would not turn, it felt like it was stuck. after a couple of weeks, it slowly started to give and finally I was able to get the knob to turn. It still is a little more difficult to turn than when it was new. Now both of the right knobs are stuck. The bottom left knob is stuck with the valve open and gas. I had to shut the gas down to the cooktop. I think the valve stem is fused stuck. Another issue that may be related, after washing the burners, the igniter would keep firing every 20-30 seconds. it stopped after about 20 minutes"