I have an Frigidaire electric range (glass top). My front left range top doesn't maintain temperature. ( Exp.) when I'm cooking and turn the temperature very low it goes low but all of a sudden during the cooking it goes high and begins to burn my food or the food begins to boil and the temperature setting is at the lowest point. So sometimes it looks like it's working but all of a sudden it goes high. I feel like something that is supposed to maintain the temperature just right, is not working properly. What part (s) do i need to replace? I asked a technician once and he said to change out the regulator behind the knob and that should do the trick but I just want to be sure before I buy something and it doesn't turn out to be the right part. The part number on that regulator is 316021501. Please help.