We bought this range less than 4 years ago - during the time I have been using it to cook for the 2 of us, two of the top element controls have had to be replaced, as they failed suddenly, going from the "simmer" setting to glowing red-hot, without warning.  Last evening, I set the oven to preheat to 325 degrees - luckily I was doing dishes, when I noticed an extremely bright light coming from the oven door window - when I investigated, there appeared to be bubbles all along the heating element, and it was glowing white and red.  I shut the oven off - thank God the controls worked ! - and the...