Thermally sensitive control

A control unit for controlling an electrical power supply circuit to an electrical heater in a liquid heating appliance, the control unit comprising:

• a leaf spring comprising a fixed end and a moveable portion that is moveable relative to the fixed end between a closed position and an open position;
• a moveable electrical contact, mounted on the moveable portion of the leaf spring, mating with a corresponding fixed electrical contact in the electrical power supply circuit when the leaf spring is in the closed position;
• a thermally sensitive actuator, operable at a predetermined temperature to move the moveable portion of the leaf spring from the closed position to the open position in which the moveable electrical contact is separated from the fixed electrical contact to interrupt the electrical power supply circuit;
• wherein the leaf spring comprises a kink between the fixed end and the moveable portion.