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Booming mini explosion on ignition

michaelheit Member Posts: 11
I have a American Standard GPH Hydronic boiler and I need some help.
I was working fine in the spring before the warm weather.
I did not turn off the pilot so that is not an issue.
What I did do was take out all the burner tubes and clean them. I also tried to clear the the jet hole with a small paper clip.
When i started it there was a wooshing explosion and I yellow flame out the front.
I boiler has 8 tubes for flame and I thought they were all the same.
I think I may have been wrong.
I think i put then back in a different order. Also I have since learned that each tube has a air mixture adjustment and I may have messed this up as well.
I also was wondering If there is a tube that MUST sit next to the pilot light and is just a little different from the others.
Finally I have learned about delayed ignition and the issue of too much primary air. I mention this as you can see in the photos I posted the sleeve in each tube seems to be over an inch from each of the jet nozzels and I was wondering if this could be a cause.


Any help and I would be grateful



  • Tim McElwain
    Tim McElwain Member Posts: 4,480
    Move the burners back to the threaded portion of the orifices.
    delta T
  • michaelheit
    michaelheit Member Posts: 11
    DO you mean to move the tubes toward the brass jet nozzels and close the space between them?
    EBEBRATT-Ed Member Posts: 10,225
    Some are pushed tight to the oarfice, some are not
  • Tim McElwain
    Tim McElwain Member Posts: 4,480
    Yes you want the burners closer to the manifold.
  • I had this happen once; found that the orifice tube closest to the pilot was clogged with a spider web and explosion happened when there was a build-up of gas.

    Not the same situation as your since you say that you cleaned the burners and orifices.

    Check that first burner tube next to the pilot light and switch it with another one. See if there is a different burner tube that has gas outlets adjacent to the pilot for quick ignition.
    Often wrong, never in doubt.
  • michaelheit
    michaelheit Member Posts: 11
    Thanks I will try this tonight.
    BTW a contractor who was scheduled to come to my house saw this post and called to cancel.
    Said he would not work on a old boiler but he would install an entire new system.
    So far everyone who ever came to do seasonal maintenance said these old cast iron boilers are so basic and so well made that only when they rust through is when you replace them.
    I will keep you posted
    Hopefully it is only a simple adjustment
  • Danny Scully
    Danny Scully Member Posts: 1,329
    edited November 2018
    I was the contractor who was scheduled to come, and I didn’t call to cancel. I simply said I would be willing to give you an estimate for a new boiler, but that I wasn’t willing to make a combustion repair on it at this time (for a variety of reasons). I agree the boiler is well made and basic in operation, however, I don’t agree you should wait for it to leak on December 31st at 11:59 pm to replace it :wink:. I am in the business of service excellence. I don’t want to be your hero this winter, but for many winters and the lifetime of a new properly sized efficient boiler. Thanks as always for the consideration and opportunity. I wish you the best of luck.
  • Tim McElwain
    Tim McElwain Member Posts: 4,480
    This is not rocket science folks just proper placement of the burners based on the photos attached to the posting.
  • GBart
    GBart Member Posts: 746

    This is not rocket science folks just proper placement of the burners based on the photos attached to the posting.

    you mean like reading the manual?
  • michaelheit
    michaelheit Member Posts: 11
    IF there was a manual to read that was first intention.
    I spent many hours attempting to find the manual for this boiler.
    If you have one please provide a copy
  • Leonard
    Leonard Member Posts: 903
    edited November 2018
    Even with non-heating repairs making detailed drawings, with ACCURATE measurements and good camera pictures BEFORE disassembly help you easily put things back the way you found them. In past sometimes had to spend 1/2 a day trying to figure out exactly where things go, no longer have those problems.

    Last night took my car automatic transmission apart to replace a gear, pics and dial caliper measurements got it back together in no time even after a part fell out.
  • Bob Harper
    Bob Harper Member Posts: 882
    You need a qualified contractor to repair or replace the unit. The burners are visibly out of alignment and the air shutters are all different. Some mfrs. do have ignition cross-over ports that align with the pilot flame and some don't. Easy enough to tell side by side. Delayed ignition can be caused by a number of things including low inlet gas pressure, dirty/ misaligned pilot, slow opening valve, obstructions in the orifices and burner tubes, air shutter adjustment, etc. Once it fires properly you'll need to do combustion analysis to ensure it is lighting off and firing properly.