Abstract: A safety and regulation valve unit for a gas installation, particularly a heating installation, comprises a duct through which the fuel can flow between an inlet and at least one outlet. An on-off fuel-valve is interposed in the duct between the inlet and the at least one outlet, and there is a movable device for controlling the valve as well as an actuator acting on the movable device in order to move it towards a first operative position in which it cooperates with the on-off valve in order to put the inlet into communication with the outlet. The actuator comprises a reversible motor with a rotor connected to a male-and-female screw coupling acting on the movable device to translate it towards the first operative position and to control the on-off valve.