UL really trusts thermal fuses, they're reliable and can not be reset which calls attention to the user that something is very seriously wrong. If the oven was getting hot enough to trip the thermals, then something was seriously wrong and replacing the thermals would not be the cure.
I'm sure that replacing the firmware was the real cure, and that's scary. What if self-clean code was causing a runaway condition? There might be consumers that jumper out the blown thermal fuses rather than paying $260 for the proper repair and then they have a runaway oven with no way to shut it down.
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