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Delayed fire from Steam boiler

My boiler guy is running into a delayed fire situation after changing the nozzle and cleaning the boiler. The burner will run for for 5 0r 6 secconds and with a "huff" it lights off. New spark box last year, Electrodes looked prety good, Chimney is big and not lined. We changed from a 4.5 GPH nozzle to a 4.0 at this years cleaning to reduce pressure cycling. Burnham V905A boiler, Beckett burner. Tech thought It was not getting enough air? Basement is vented to fresh air. Any ideas? thanks T.


  • Paul Fredricks_3
    Paul Fredricks_3 Member Posts: 1,557

    Has he tested the unit using the proper instruments? What is the CO2, CO, Excess air reading, smoke, draft? What's the pump pressure? Is the burner set to factory specs?

    Lots of possibilities.
  • dana_3
    dana_3 Member Posts: 57
    delayed ignition

    simple question??? if it ran fine before the cleaning, then it's something in the setup
  • Beckett does not spec

    a 4.00 nozzle on any of the V9 Boilers. There is a rather drastic air band change from the 904's 3.5 nozzle to the 905's 4.5 nozzle. Beckett's specs are on Burnham's Web Site. Might try for a happy medium.

  • V9 Delayed Ignition

    I would suspect that what might have changed would be the Breech Damper setting. This is a pressure fire boiler meaning the boiler operates under positive pressure over fire and through the boiler. What controls that is the fixing bolt position on the Breech Damper. If you have that too far or wide open, the over fire draft will now be negative and the ignition will try and occur too far off the head. I've been on enough of these installations to know that way too many technicians think boilers like this are supposed to operate with a -.02 Over-fire draft and the result is they play with or leave the Breech Damper wide open.

    Glenn Stanton

    Manager of Technical Development

    Burnham Hydronics

    U.S. Boiler Co., Inc.
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