It wont be the t/stat.It will be the oven flame failure device.If you look at the oven burner you will see a rod bridging it,this is the FFD probe.This connects to a valve situated at the side of the burner but the cooker has to be stripped down to replace it.Unfortunately getting a bit pricey nowadays i would imagine.Its usually only the t/stat when it burns everything.
Tony S, December 2008