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  1. #1

    Utica High Efficiency boiler "flutters" when gas is applied during ignition cycle.

    I have a Utica High Efficiency boiler that flutters (sometimes softly, sometimes hard) when gas is applied during the ignition cycle. This fluttering sometimes interrupts the cycle causing it to purge and try again. If it fails three times in a row, the system goes into lockout and requires manual restart (valve indicator on control board flashes).

    Does anyone have any recommendations as to what the possible cause of this is? Utica tech support said to check CO2 levels with a combustion analyzer but one is not available. They also said that supply gas pressure needs to be minimum of 4 in W.C. while firing and we are only getting 3.5 in W.C. Could this be the problem?

    Any recommendations would be greatly appreciated.

  2. #2
    Join Date
    Jan 2004
    Location
    PA
    Posts
    68,764
    Yes, it could be.
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    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  3. #3
    Join Date
    Dec 2010
    Location
    WV
    Posts
    115
    is this an Ultra299 or Ultra399? if so these are modulating boilers..and are my hands down favorite boiler...How bout a model#

  4. #4
    It is a series Q90-200, model UB90-200, serial 350500221. A little history on the system: When my boss took over this system it was installed in an apartment complex controlling 15 zones. It was determined (by an engineer) that the system was incorrectly piped (did not have a bypass loop). The engineer told the property owner that the incorrect pipping may have damaged the system. The system has "fluttered" ever since my boss took it over but seemed to get worse after cleaning the burn chamber this fall. Per the recommendation of the Utica Tech Support person, I re-cleaned the burn chamber and that improved the fluttering slightly but not completely. When the combustion intake is removed the fluttering stops. There seems to be a back pressure created at the moment of combustion that causes the pressure switch to flutter which in turn causes the gas valve to flutter. Also, the carbon monoxide reading at the outside exhaust is 4000ppm. That is as high as my reader goes so it may be higher.

    Any recommendations or assistance would be greatly appreciated.

  5. #5
    Join Date
    Oct 2011
    Location
    Las Vegas, NV
    Posts
    526
    Did it have the 4000ppm CO with the intake pipe removed?


    Sent from my Evo 3D CDMA using Tapatalk 2

  6. #6
    Yes

  7. #7
    Join Date
    Jul 2009
    Location
    Columbia, MD
    Posts
    4,470
    hook up a combustion analyzer to the boiler. 4000ppm is way to high and should be corrected to fire under 400ppm. if over 400ppm ANSI standards is to red tag and disable boiler.

    could be your venting length, venting size, incorrect venting, etc.....

    combustion analyzer should tell you your problems.

  8. #8
    Join Date
    Aug 2001
    Location
    Pavilion, NY
    Posts
    2,196
    I have worked on many q90-100 and they had a burner change that resolved ignition rumbling noise.. I will see if I can find the bulletin. I had one last year that I got involved in,,, replace the burner and it was like night and day.. Check your inlet screen (sandwiched in the Fernco)
    ...

  9. #9
    Join Date
    Aug 2001
    Location
    Pavilion, NY
    Posts
    2,196

  10. #10
    Join Date
    Oct 2007
    Location
    ontario
    Posts
    92
    Ive found any little cracks in them burner tubes will make them act up.
    I reject your reality and substitute my own.

  11. #11
    This system already has the new burner tube.

  12. #12
    Does anyone have a PDF of the manual for this boiler so I can verify correct vent length?

  13. #13
    Join Date
    Aug 2001
    Location
    Pavilion, NY
    Posts
    2,196

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