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Lose of prime

pgrant89 Member Posts: 1
I was wondering if some one may be able to help me out with this problem I am having with an oil burner that as been giving me problems.

So it started last year there was a crack in the oil line it was buried in concrete so I had the guy replace the tank. I ran new oil line to it 3/8 coated line the old line I could never get a solid prime out of it this one I get a solid prime but after a couple of weeks it loses the prime it's a bucket cf1400 burner gravity fed the tank is close to 20' away


  • STEVEusaPA
    STEVEusaPA Member Posts: 5,974
    edited September 2017
    If it's losing it's prime you have a vacuum leak and/or possibly (but not likely) a bad pump. A vacuum leak could be anywhere in the fuel system from a bad seal at a flare fitting, bad seal at filter gasket and/or bad seal at the fuel pump cover.
    Have the guy who replaced the tank and the oil line do a proper power bleed. He should also do a vacuum check on the fuel line and the fuel pump and check the pressure and cut-off for the fuel pump. Also check all fittings from the tank to the burner.
    If he doesn't know how, doesn't believe in it, and/or doesn't have the right tools or skill, you should find someone else.
    Hopefully when you replaced the tank you didn't dump the old oil into the new tank.
  • Robert O'Brien
    Robert O'Brien Member Posts: 3,474
    Gravity fed?
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    EBEBRATT-Ed Member Posts: 13,135
    You should absolutely never loose prime if it is gravity fed.

    Need pictures
    HVACNUT Member Posts: 4,864
    This is for your home? That's a big BTU burner.
    One pipe oil line off the bottom of the tank?
    Same level or higher than the burner?
    If so, you'd have a visible oil leak.

    Is the fuel pump the "B" or "H"?
    The H pump needs an external (field installed) bypass line for low fire.
    With the B pump, it's done internally.
    When the high fire solenoid valve closes, and pressure drops from 300 psi, that extra oil needs to be returned to the inlet.

    I don't think you have a loss of prime. I think there's a problem with the pump settings, piping, or adjustments.

    Call a service company that has experience with commercial burners.
    HVACNUT Member Posts: 4,864
    Any update @pgrant89 ?