Abstract: A method and apparatuses for embedding a resistance heating wire in a thermoplastic element having a surface such as an electrofusion saddle coupler by providing an operating head including heat grooving mechanism and wire inserting mechanism, the operating head and the thermoplastic element being integratively movable in all directions one relative to the other; using the heat grooving mechanism and the relative movement for creating a groove in the surface of the thermoplastic element; and, thereafter using the wire insertion mechanism and the relative movement for inserting the resistance heating wire into the groove, to implant the resistance heating wire in the groove.