De Dietrich 300009075 3 pin connector fitted Power supply

This 3‑pin connector power supply, listed under De Dietrich part numbers 300009075 and 336.640.004, belongs to the category of plugs and connectors used in boiler and burner electrical systems. Components of this type carry mains or low‑voltage supply from the burner control to powered devices — such as the fan, ignition transformer, or fuel valves — and also route signal wires between the control board and sensors or actuators. The “3‑pin connector fitted” designation indicates that the power supply comes with a pre‑terminated three‑pin plug, which simplifies replacement when the original connector has been damaged or lost. When selecting a replacement connector of this kind, the key parameters are the pin count and pitch, the conductor cross‑section (to match the current drawn by the load), the insulation temperature class, the length of the cable, and the terminal type (screw, crimp, or push‑fit). Because connectors are keyed to prevent mis‑wiring, the physical shape of the housing must match the mating socket on the control board or component. A mismatched pitch or keying will not fit, even if the pin count is the same. In fault‑finding, connectors are routinely suspected because a poor contact can mimic any electrical failure — loss of flame signal, intermittent burner lockout, or erratic modulation. Before replacing the entire power supply, check that the pins are clean and that the connector locks securely. If the existing connector shows signs of corrosion or heat damage, replacing it with a like‑for‑kin unit such as this one restores reliable electrical continuity. No further compatibility information is available from the catalogue data beyond the brand and part numbers listed.