How to Replace The Nozzle and the electrodes of an Oil Fired Heater

OK, now before we start the most important thing to do here is turn the power off to the unit.


Oil feed disconnected

Oil feed disconnected

Remove the two little tabs / screws that are holding down the transformer and flip it out of the way. At this point, you really want to make sure the power is off. Those two little springs on the transformer are what gives the electrodes the high voltage of power that is sure to wake you up.


The picture to the left shows the oil feed line disconnected with just some paper towels under it to pick up any oil that may come out. Remove the line and the nut on the oil feed pipe. That is the only thing holding the whole assembly in.


100_1441Now all you have to do is twist and pull the unit out. Just be gentle while doing so.

You’ll notice some wires, no biggie, remember the power is off, right?




100_1442OK, now that you got the unit out let’s take a good look at. More than likely yours doesn’t look as bad as this one. This one went many years without being serviced. Dead center you’ll the nozzle. For now, leave it alone while you clean the heck out of this unit. The funny shape you’re looking at here actually creates a twisted air flow to the flame that will also have a twist to it as well. Allowing the air to come in, and as you can see this one here was about 75% plugged up. So with a small wire brush and rag, you should clean this up real good.


An automotive carburetor cleaner works really well on this.


100_1443Now here you see the electrodes. Now to the untrained eye they look in a good shape. However, they are supposed to have a point at the ends. Notice all the unburned wet oil. Yup, not good.





100_1443Now remove the old electrodes held in by that one screw in the center with a bracket.


Removing the nozzle is as easy as can be. However done wrong and you’ll be in for it. YOU MUST USE TWO WRENCH’S AT THE SAME TIME. Very important you do, otherwise you can twist everything. Once you unscrew and remove the nozzle, keep it. Don’t get rid of it.



100_1446You’ll notice the old nozzle to the left in the picture. Clean the sides of it and you’ll see some numbers on it. One set will be the flow, this one is 1.00 That means 1 gallon per hour. The 70 means the degree that is will spray (flame). Make sure you get the same one. For other reason, yes you can change this to a different one. Say one that uses more oil per hour to make more heat. But that doesn’t always work like that. So check your system tags for the specs on which one it wants. Chances are yours could have the wrong one in already and that’s why you’re using so much oil.




100_1445Just a tighten a little, too much and you can break the electrode.






100_1450OK, so did everything go so far, good I hope. This is the part that separates the boys from the men. Why, simple, boys will read those instructions that came with the electrodes and tool you now see. Go ahead, this is the internet. No one will know you went to read them before you came back here to read more here. From this point if you did read those you won’t need me anymore.


But just in case your dog eat them.


READ THE GAUGE. On the gauge / silver tool, there are marks. One marks the cl (center line) of the nozzle. Hold the gauge as shown and line up the tips of the electrodes to the two outside lines of that center line. It’s about the thickness of a nickel. HOWEVER, you’ll need those instructions, in there you’ll see that they have different specs for different units. The one here wanted the trips 5/16 above the nozzle trip and 3/32 apart.


100_1451All together and doubled checked, oh and all nice and clean. Don’t forget to change the filter before you start it up.






100_1452All back in and waiting to make some heat. Just go slow, take your time and be clean. Place the transformer back down, tighten the screws, change the filter, bleed out the air and you’re now a pro.

How to Replace The Nozzle and the electrodes of an Oil Fired Heater
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  1. Dominick January 18, 2014
  2. Dominick March 27, 2013
  3. David March 26, 2013
  4. steve phillips October 2, 2012
  5. dominick December 4, 2011
  6. blackrabti November 30, 2011

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