A valve of a heating, ventilation and/or air conditioning system includes an actuator with a housing and a shaft which is arranged at least partially in the housing and which can be coupled directly or indirectly to the valve such that the valve can be adjusted during a rotation of the shaft. A hand-operated element can be coupled to the shaft via an overload clutch arranged between the hand-operated element and the shaft which limits a torque which is transmitted onto the shaft by the hand-operated element to a predetermined maximum value. The overload clutch has a coupling element and a replaceable spring element which presses the coupling element against the shaft such that the maximum value for the transmittable torque is dependent on the replaceable spring element.