Author Topic: Too Much unburnt oil  (Read 807 times)


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Too Much unburnt oil
« on: October 07, 2021, 02:55:13 pm »
Hello all,
I have been using an inherited waste oil burner for a few years now.  I have posted in previous years and people here were such a big help!  My unit is old.  very old.  a Clean Burn unit.  but it has been running good the last couple years since I rebuilt it.  it is a burner mounted onto a converted coal boiler.  Anyways, end of last year, I started having this random problem where it would just randomly shut itself on and off real quick.  like the whole thing lost power, then suddenly got power.  that problem manifested itself worse the beginning of this year, and I traced it to a bad controller - not a big deal, done.  But I actually moved my whole burner to a different spot in the room over the summer (lots of renovations in the furnace room including replacing my main soft coal boiler with a stoker)  Anyways, so the issue I am having now, is too much unburnt oil, when i shut it off and open up my unit the inside of my boiler is coated with oil - and the smoke out the flue is not clear like it usually is.  I thought I wasnt getting good spark, but my transformers tests ok (I can pull a real good spark with a screw driver) but my electrodes were pretty crappy, so I replaced them.  They are positioned right according to specs.  it is now running better (more consistently) but I still have unburnt oil.  I turned the oil pressure down a little lower than where I kept it last year, about 5psi or just below (last year around 6) but still no difference.  I am trying to figure this one out

Things that changed during the renovations
- using a different chimney
- possibly sucking a little more air (I havent adjusted the air inlet at all, but I see a few small gaps around it that I havent finished caulking) 

Would any of these effect it?  I thought too much air should not cause unburnt oil, but maybe i am wrong? 
I am going to caulk it more, today or tomorrow, But wanted to get the ball rolling with some opinions.  Thanks for the help!


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Re: Too Much unburnt oil
« Reply #1 on: March 05, 2022, 05:18:36 pm »
My friend also runs a WO burner and I noticed that his has an extra cylinder inside the boiler which I believe is to burn off any oil that splatters in the boiler. This cylinder is about 2'' smaller than the diameter of the boiler and is tilted slightly forward to allow any unburnt oil to travel forward towards the back wall of the boiler. At this point it should be burnt off by the flame.

Hope I have explained the setup.