Zanussi electric oven.

The problem is usually a contactor or relay. The thermostat usually doesn't directly control the elements. Follow the wiring diagram or look at the wires from the thermostat. they usually go to a small box and then to the elements The contacts may sometimes stick or always stick. This part is a lot cheaper than the thermostat. Another problem is a burned out element. (Usually the bake element) This can short to ground and not let it turn off. When the elements are on they should glow evenly all over with no hot spots. Look at the broil element also. It is usually at least part way on during baking.