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Oil burner burning thick black smoke

Mark_24 Member Posts: 9
Help! I have a Beckett AFG oil burner in a Weils McLain 68 furnace. I practically rebuilt the thing over the past year. New nozzle/gun/electrodes (adjustment triple checked) new fire box, new fuel pump, new fire box, heat exchanger cleaned out. I noticed that someone along the line installed a .5 80B nozzle at some point to overcompensate for a past draft problem I think. Anyway, it burns way too rich now with thick black smoke pouring out of it. With some advice, I checked with Beckett and Weils Mclain, and another internet forum. The best advice I got was to install the original nozzle. I threw in a 90 80B nozzle. Beckett said it comes with a 1.0 80B, and Weils Mclain says the maz is .95 GPM, not 1.0. So I threw in a 90 like a furnace tech did long ago. It still pours out thick black smoke. How do I better adjust this? I believe the air intake has to be adjusted. Help! -Mark


  • Jim_19
    Jim_19 Member Posts: 31

    I'm a reasonable handy home-owner. But I draw the line at trying to fine tune any system that can kill me in my sleep if I make a mistake. I don't fool around with the circuit breaker panel or the boiler. I suggest that you get a licensed technician with the proper test equipment to inspect and adjust what you have done, BEFORE YOU KILL YOURSELF AND YOUR FAMILY!

  • ed wallace
    ed wallace Member Posts: 1,613
    black smoke

    jim is right call your oil company unit needs help now

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  • Guy_5
    Guy_5 Member Posts: 159

    Even though you have tried to adjust the fuel side of your burner, there is another side as well. Have your oil technician look at the air side-both in and out. Have him/her check that the burner fan is not fouled with lint or dust. Have them check the condition of the burner head, and if it is still in place. The end of the blast tube may have become damaged from the past "draft" problem.
    Also, have them try to ascertain that the flue gasses are actually going up the flue. Squirrels build nests, flue liners fail, and some flues have corners built in to them that make clearing them difficult.
    One last thing to look at on the fuel side- Is the fuel unit delivering the proper pressure? If the nozzle size was reduced, there is a chance that the pump pressure was raised at that time. Now , with the seemingly proper nozzle in place, the boiler may actually be over-fired.
    I personally have had great luck with Hollow "A" nozzles in that equipment, firing for 1 size smaller boiler (.75 80A for you).
  • Bob_19
    Bob_19 Member Posts: 94

    to see if oil is impinging the walls(carbon black buildup), if so the fuel pressure is most likly to high.
    If not most likly the fuel/air mixture is way off, black smoke is the result of in-complete combustion, causing high CO levels, which is a silent killer.
  • Steve Eayrs
    Steve Eayrs Member Posts: 424
    Your boiler most likely.......

    has a Blue Angel oil burner? If so the alignment of the nozzle assembly with the end of the burner tube is real important. The adjustment screw for this is too tempting to the home owner, and often ends up where it won't work well, and will smoke a lot.
    Unless your time is worth nothing, let someone with proper equipment and knowledge adjust this and tune it up for you. You may have already spent more in parts than it would have cost to have someone else do it the first time.

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