This DIY repair guide gives step-by-step instructions on how to replace the thermal switch in a wall oven. The thermal switch trips to protect the oven from excessive heating. If the thermal switch trips, the oven won't heat until you reset the switch by pressing the red button on the switch body. Replace the thermal switch with a manufacturer-approved wall oven part if the oven won't heat after you reset the switch.
The self-cleaning cycle sometimes causes the thermal switch to trip; if it trips when the oven isn't self-cleaning, investigate what caused the oven to overheat before using the oven again.
These steps show how to replace the thermal switch in Kenmore, Frigidaire and Electrolux wall ovens.