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Phillippe
Phillippe Member Posts: 2
in THE MAIN WALL
Servicing a Dunkirk Q90 LP. @ignition the flame flutters until it catches. Removed burner and it looks clean. Outside regulator has been changed, CO2 correct, incoming LP pressure correct, igntion fan speed correct, vent and air within specs.Once it ramps up the fluttering disappears.

Comments

  • Mark Eatherton
    Mark Eatherton Member Posts: 5,852
    Fluttering...

    is usually an indication of pressure regulators that can "see" each other, and their diaphragms set up a harmonic resonance. Most negative pressure gas valves need at least 15' between the primary regulator and the appliance regulator.



    I've also seen situations whereby 2# gas to inches of water column regulators that have the slow bleed vent on them will also cause the fluttering condition. Running a full size vented regulator to the outside eliminated that problem.



    Is your fuel pressure stable through the whole process of start to run?



    Is this a modulating appliance, or a bang bang appliance (they made both)?



    ME

    There was an error rendering this rich post.

  • Ironman
    Ironman Member Posts: 7,441
    Q90

    Which model Q90 (size)? What's the age?



    ECR has an updated burner for some of the older Q90's that corrected some ignition/combustion issues. Anything made in the last 3 years or so will have the new burner, but prior to that may need the upgrade.



    If it's got the new burner, then I'd look at what Mark suggested.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
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