blue / white flash from rooftop?

Discussion in 'Shop Talk' started by .netDude, Nov 28, 2005.

  1. .netDude

    .netDude Well-Known Member

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    I saw a really bright flash outside, thought it was lighting, but there was no sound. Someone driving down the road stopped in and told me they saw a big bright blue then white flash above the roof. They said it was almost the size of the roof.
    I just replaced a gas heater with a wood stove. I put it in yesterday and lit a small fire. Tonight, I built a bigger fire, and I'm thinking that there may have been some residual gas fumes in the chimney and that I finally generated enough heat to ignite it. Does that sound right? The chimney is flue lined, and was used by a woodstove prior to the previous owners putting in the gas heater.
    Other than that, what would cause the big blue and white flash?
     
  2. Ross

    Ross Moderator Staff Member Supporter

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    Wow its not exactly lightening season and your idea sounds more plausable. Makes me wonder how solid that chimney is because it shouldn't be able to retain gas but it might accumulate in the attic!!
     

  3. uncle Will in In.

    uncle Will in In. Well-Known Member Supporter

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    Is the gas burner still hooked to the chimney? Thought maybe it could be leaking gas up the flue. Is the roof still up there? lol
     
  4. moopups

    moopups In Remembrance

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    Could have been a methane gas flash over, is there a septic tank nearby with a roof vent?
     
  5. Nature_Lover

    Nature_Lover Well-Known Member

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    My first impression was a possible static discharge.
    (your small fire should have flushed the chimney with the first fire's draft)
    Did it happen immediately after lighting the big fire?
    Do you use a humidifier?
    Do you have the roof grounded?
    Do you have the roof vented?
    Is the gas turned off at the supply cut-off, or are you still using it for dryer/hot water?

    The other possibility is UFOs, lol.
     
  6. .netDude

    .netDude Well-Known Member

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    Yep, the roof is still there! The gas burner was removed the previous day,and I did light a small fire in the wood stove that day.

    There is a septic tank nearby, it was put in at the beginning of the year. I don't know if there is a roof vent near where it happened, I'll take a look. Is a methane flash a common occurance?

    If the chimney was not solid and the gas accumulated in the attic, wouldn't it have blown the roof off, or at least started a fire?

    In the attic, where the chimney meets the roof, the bricks were a little warm, nothing that I would worry about normally, but the bricks by the floor were not. I don't know if it's corelated or not, just noticed it when I was checking the attic.
     
  7. .netDude

    .netDude Well-Known Member

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    It didn't happen right away with the second fire, maybe an hour or so after. I don't use a humidifier.
    How do I tell if the roof is grounded? There are lightning rods up there. The vents are on the attic dormers (3), not on the roof. When I replace the shingles, I intended to add some roof vents.
    The gas line to the gas burner is disconnected. It was shared by the dryer gas line, but that now runs on it's own line. A plumber did that yesterday (the day of the flash...)
     
  8. Janon

    Janon 993cc Geo Metro

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    The roof/attic area - blue flame - fact that natural gas is lighter than air - work done on the gas lines recently. Everything points to natural gas that fueled the "flash".

    cheers,
     
  9. Nature_Lover

    Nature_Lover Well-Known Member

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    I'd call the plumber and tell him what happened, he apparently didn't vent the basement/heater room when re-running your gas supply line. It could have started a serious fire.

    Humidifying your heated air makes it feel warmer, and helps prevent dry skin and static during the winter. I always have my humidifier running when my woodstove is burning.