What is the standard distance apart between electrode ends in the oil burner setting (the 3/16" end spacing refers to the ends, while the 1/8" is the ahead-of-nozzle setting)?

• A. 1/8
• B. 1/4
• C. 3/16
• D. 1/16

Answer: (C)

The distance between the ends of the ignition electrodes is what sets how easily the spark can jump and establish a flame. For oil burner ignition, the standard end-to-end gap is 3/16 inch. This gap size provides a reliable arc under typical operating voltages without causing excessive wear or arcing elsewhere.

The 1/8 inch measurement you mentioned is a separate adjustment—the distance ahead of the nozzle from the electrode tips to the nozzle. It affects where the flame forms relative to the nozzle, not the gap between the electrode ends.

If the end gap is too small, the electrodes can arc too easily or wear quickly; if it’s too large, the spark may not reliably bridge the gap, leading to failed ignition. To set it correctly, measure the gap with a feeler gauge and adjust the electrode leads slightly in or out until you reach 3/16 inch, taking care not to bend or damage the insulators.