How do I adjust my electrodes?

Adjusting electrodes in your oil burner is something normally done by a professional, however it is not rocket science.  If the homeowner is capable of doing most home repairs, he/she can adjust electrodes.  The standard cautionary  notes apply:  make sure you turn off the system, and be careful because you are working around fuel oil.   Make sure you don’t over-tighten the holder, you do not want to crack the porcelain.   If you do not feel comfortable, defer to a professional.

loosing the electrode adjustment screw

loosen the adjustment screw




1.  Use a wrench or screwdriver to loosen holder to adjust or position electrodes.





Setting the gape between the electrodes tips

setting the gap between the tips





2.  Set gap at 1/8″





Setting the electrode 1/8" forward of the nozzle tip

setting electrode tip 1/8" forward of nozzle tip



3. Set electrodes 1/8” forward from end of  nozzle.





Setting electrodes up from nozzle center 1/2"

Setting electrodes 1/2" up from nozzle center







4. Set electrodes about ½” from center of nozzle to center of electrodes.

showing use of electrode setting gage

using electrode gauge







You may also use a gauge. Our # 66-105






Lastly, don’t forget to tighten the adjustment holder nut you loosened in step 1.


The table below shows some nozzle setting recommendations

Nozzle degree GPH Figure (2) Figure (3) Figure (4)
45 .75 to 4.00 1/8” to 3/16” ¼” ½” to 9/16”
60 .75 to 4.00 1/8” to 3/16” ¼” 9/16” to 5/8”
70 .75 to 4.00 1/8” to 3/16” 1/8” 9/16” to 5/8”
80 .75 to 4.00 1/8” to 3/16” 1/8” 9/16” to 5/8”
90 .75 to 4.00 1/8” to 3/16” 1/8” 9/16” to 5/8”

If above 4.00 GPH you may need to increase Figure (3) by 1/8” to enable smooth startup.

We list many common electrodes on our website.


  1. Scott

    Perfect table of measurements, thanks, it helped when I was in a bind

  2. patrick

    are the adjustments for electrodes the same for waste oil furnaces?

  3. If you have a digital electronic primary control, the electrodes only fire long enough to ignite the oil and then shut off. Running all day would not affect the electrodes. However; the older style primary controls, like the Honeywell R8184G, fire the electrodes continuously. Running these heaters all day long would cause the tips to burn away faster.

  4. Jeff Feineigle

    Chart was a big help, made changing nozzle and electrodes a 20 min job. Thank you

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