Help with Gas Furnace

Well, I decided to not wait until it gets cold out and try and do some matinence on my natural gas furnace while the weather is warm.
I cleaned out the fire box, and cleaned the gas jet, replaced the thermocouple and re-assembled everything.
The pilot light stays lit, and everything seemed fine until I turned up the thermostat. The firebox lit up, but not before a large back-flash shot out behind the gas unit. After the flash died, the furnace was running fine.
Needless to say, I don't want fire shooting out the back every time the furnace kicks in.
So far, nothing is adjusted for flame color and venting. Will this go away after the air mixture is correct, or am I missing something ?
Jim
--
" The only stupid question is the one
never asked --- except that one!"
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This is Turtle.
I think you have the burner [ lighting runners ] out of line. Go back and straighten the burners in the row and have all of them straight up and down to lite good. What you have is call late ignition and can be cure by getting burners straight and clean. If they are not clean at this runner section you will get the same thing.
Answer in a nut shell. Burners out of line.
TURTLE
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Do i have an answer. Before you lose your house and family, have a trained technician work on the unit!! Where's your brain? Eric G. education CANNOT buy common sense
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Hi Eric.
Thanks for your concern. The furnace is off and the gas is shut off. I do respect your opinion about getting a trained tech, and I will if all else fails.
My guess is you are a tech
Right ?

trained
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if
After the fire you will no longer need the HVAC tech to fix the problem.
You'll need to replace the whole system.............. ..........along with the rest of the home!!
Be smart and call the tech now!!
-- kjpro _-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>_-~-_>
( kjpro @ starband . net ) remove spaces to e-mail
Want it done yesterday? Or done right today, to save money tomorrow!!
_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>_>
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Thanks everyone for the advice. Including those who were concerned for my life and property.
I am happy to report that the furnace is up and running fine. As it turns out my furnace was converted from oil to natural gas years ago. The burner unit was designed to take the place of an oil fired unit. I am going to make the assumption that this sort of burner is far easier to maintain that conventinal gas units.
The late ignition was caused by excessive flow of gas. There is a large needle valve at the end of the burner tube that regulates the gas flow. I took it all apart and found that it was both out of align ( concentric ) and very dirty. I cleaned and polished it and re-aligned the concentricity. After tweaking the flow awhile I was able to get a fast clean ignition with little or no blow back. I believe the faster flow was causing the gas to ignite in front and blow the gas behind it out behind the unit.
Another question for the experts. There are vents that slide along the burner unit that control air flow. Is there an optimal way to adjust them. Right now, the flame looks bluish at the base with yellow tips. Is this best ?
Thanks
Jim
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Not really...its normally better to go ahead and change out the units...I never had much faith in the old conversion kits...altho..there are plenty out there. Also...the kits normally cost as much as a furnace..

concentricity.
Its not a Wayne conversion is it? If it is...suggest you get a new seat.

Right
Nope..blue flame..blue tips, with a lighter base..almost white.. That would be a good burn. Yellow is cool, and shows incomplete combustion, OR, its a residual of the cleaners you used to clean the unit...

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It's an Adams.

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