The heating element on the left front works, but can't be controlled. The knob that controls it will turn it on, but when I turn the element off, the "element on" red light on the panel sometimes stays on, and the element may or may not be hot. Sometimes you have to turn the knob back past "off" to the left to get it to go off. The knob itself does not feel loose, and changing it with one of the other knobs doesn't help. I think I may need a new switch, which I think is #54. Do you think that would cure my problem, or have any other advice? Thank you.