A failed control thermostat can prevent the oven from baking on a wall oven that uses dials for the oven controls. On a wall oven with a digital display, a failed electronic control board or relay control board may keep the oven from working. A bad temperature sensor probe will also prevent the oven from heating. A broken bake element in an electric oven or a failed igniter in a gas oven can also cause a heating failure. For more troubleshooting tips, watch our electric wall oven won't heat video or gas wall oven won't heat video to figure out and fix the problem.
Many ovens have a thermal fuse or a thermal switch that protects the oven from overheating. The thermal fuse or thermal switch trips when the temperature in the oven gets too hot. After the device trips, the oven won't heat. If your oven uses a thermal fuse, you'll need to replace a tripped fuse because you can't reset the fuse. You'll also need to investigate the cause of overheating if the oven got extremely hot before the fuse tripped. A stuck relay on the electronic control board can cause the bake or broil element to heat constantly. Check the control board for a burnt spot or melted relay. Replace the control board if damaged.
If your oven uses a thermal switch, you can reset the switch by turning off electricity to the oven, removing the exterior back oven panel and pushing the red reset button on the back of the thermal switch. If the switch tripped during the self-clean cycle because excessive residue inside the oven caused the oven to overheat, then the oven may work properly after resetting the thermal switch. If the thermal switch continues to trip and the oven doesn't overheat, you'll likely need to replace the thermal switch because the switch is tripping at the normal oven operating temperature. If the oven overheats and trips the thermal switch after you reset the thermal switch, then you'll need to investigate the cause of the overheating as described above.