armstrong ultra 3 80 ???

this furnace makes a clicking sound and you can see the pilot light come on while it is clicking but wont fire up the burners when it stops clicking pilot goes out ? but the small fan keeps going then it starts clicking again. i dont have a manual i think it is 10-12 years old any ideas???
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braveops
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This is Turtle.
I can't see it from here but it sounds like a flame sencer on the pilot lite is out or a roll out button is tripped out. Some Shut Down device is dropping it out.
TURTLE
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Cant be a roll out or any other safety or the sequence would not make it to energizing the pilot. Has to be the flame sensor, weak pilot flame or the ignition module itself....Or is the main coil on the gas valve getting 24 volts and not opening?
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This is Turtle.
i have to differ with you on the roll out being tripped. Lennox on some of their models only put the roll out in the main gas valve 24 volt circuit and not in the pilot valve circuit of the 24 volt system. There is two circuits for the pilot gas valve and the main gas valve. There is two gas valve in the gas valve and the circuit board will let the pilot lite gas open after the vent prover switch proved and the turn on the gas to the pilot but then when the circuit board read through the main gas valve circuit. It would not fire and time out for the main not opening in a set time. It can make it to the pilot gas on and still be a roll out. I think Goodman done this also with the spark ignition system also on some gas packs a few years ago.
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Hey Turtle, Look at the scematic for an armstrong, this is what unit is in question. And I would love to know what model of any furnace made would have a spark ignition that has the roll outs or limits past the spark cycle of the sequence or operation. No offence intended, but, in order for any spark ignition to get to the spark cycle, all the safeties must be closed.
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