A magnet valve coil unit includes a magnet coil and a circuit board connected thereto, encased by a molding material. An LED on the circuit board signals a switching status of the magnet coil. The LED is surrounded by the molding material at least in part. A light guide element is arranged in contact with the LED such that it directs light radiated from the LED to an external surface of the magnet valve coil unit. The magnet valve coil unit is manufactured by applying a deformable, transparent mass on the LED of a pre-assembled component containing the magnet coil and the circuit board on which the LED is arranged, and placing the pre-assembled component in a tool mold. The light guide element is arranged to be in contact with the transparent mass, and the pre-assembled component is encased with a molding material.