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Yellow soot

Patchogue Phil_29
Patchogue Phil_29 Member Posts: 121
in THE MAIN WALL
It's not underfired that I am sure.

OK, what are the lowest limits that this unit could be set to? I know it is difficult to say w/o taking readings.... I am just curious as to a ballpark figgure?

Comments

  • Patchogue Phil_29
    Patchogue Phil_29 Member Posts: 121
    Yellow soot

    What causes yellow soot in the flue of an oil fired boiler?

  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    High sulphur content

    in the oil?

    What are your combustion test readings?
  • Leo
    Leo Member Posts: 770


    The unit has been condensing, you find this alot in "cold start" boilers.

    Leo
  • Patchogue Phil_29
    Patchogue Phil_29 Member Posts: 121
    Not a cold start

    It's a single pass New Yorker S-AP boiler with standard Beckett gun.

    Could this happen with this setup from lowering the limits too much in the summer?
  • J.C.A._3
    J.C.A._3 Member Posts: 2,980
    Read the boiler manufacturers instructions....

    If they are still available.... and if not, make provisions for a system bypass.

    Cold return temps are the most likely culprit, find the preferred way to avoid them. Chris
  • Leo
    Leo Member Posts: 770


    Limits too low or putting to small of a nozzle from what is speced. If none of these try the by pass piping that was suggested.

    Leo
  • Firedragon_4
    Firedragon_4 Member Posts: 1,436
    Excess air!

    It's from unburned fuel in the fluegas. You're operating on the Lanthier Scale as opposed to the Shell-Bacharach Scale. Need to adjust with an ohmmeter and get 'True Zero' smoke, FACT!

    BTW, you can also get to the right place by tuning for minimum CO, not highest CO2.
  • Firedragon_4
    Firedragon_4 Member Posts: 1,436
    If you're below

    75% of the maximum firing rate you're underfired as per ASME Section IV.
  • Patchogue Phil_29
    Patchogue Phil_29 Member Posts: 121


    I meant triple aquastat settings.
  • Steve Ebels_3
    Steve Ebels_3 Member Posts: 1,291
    Typically

    You don't want the circ running on older style boilers unless the boiler temp is above 140* to be safe.

    I'd also suspect garbage fuel with a high sulfer content.

    Or condensation in the flue caused by A: low boiler temps, B: improperly tuned burner, C: burner end cone dirty or worn affecting the flame pattern, D: Draft problems of one sort or another.
  • Zott
    Zott Member Posts: 1
    what is causing yellow soot in my oil furnace heat exchanger

    i have a new armstrong horizontal oil furnace Mod# LHR80C57/72D12 . my first one cracked the exchanger in about 7 years. this one is only 3 years old and is showing signs of what looks like sulphuric acid in the smoke pipe and heat exchanger. small damp yellow spots that turn to powder when i brush them. i have only seen this in gas flues in the past. the chimney is a healthy 8" terracata and my smoke stack 6" pipe  10' long with one 90. im running the .50 nozzle which is the correct size for this burner. Is it the stack temp. not getting high enough?
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