My furnace blower starts runs for a few minutes and then stops. The two green LEDs are on-the amber one is not. The igniter does not get hot. Dead igniter?
Thanks

By furnace blower, which one you talking about ? The smaller inducer motor or the much bigger blower that blows air into your living space,
It makes a difference as to what kind of an answer to give you

If at no time the glow plug glows, check for 120v at glow plug connection when it should be glowing. If it is getting 120v, then yes, your igniter is bad. If you don't ever get voltage to glow plug, then I would start looking at pressure switches, and please answer wmproops question as to whether or not the draft inducer blower is coming on when there is a call for heat.

Actually, yes, both blowers function. There is no juice to the igniter and the amber LED does not light-only the two green LEDs. I just replaced the motherboard with a new and the same result-blowers and no juice to the igniter. Heat sensor dead?

Sorry gentlemen, I was wrong. Only the smaller inducer fan runs, the big fan does not run. My mistake.

OK, the bigger blower won`t run till the heat exchanger get to a certain degree, chances are you are in need of a igniter,, but to be sure you should do as mygirlsdad said,, check for 120 volts to the igniter before you replace igniter,you could possible remove the igniter (very carefully) because they break very easy and inspect for cracks,burned spots that are pretty easy to see

. There is no juice to the igniter and the amber LED does not light-only the two green LEDs.

Okay, if no voltage to igniter, I'm guessing you have a pressure switch problem(cuased by plugged exhaust or combustion air vents, plugged pressure switch hoses or ports, plugged drains hoses or trap, weak draft inducer, or bad pressure switch). The amber light will only come on when flame is sensed(burners are fired), so its normal for the amber light to be off if there is no flame. First, check to make sure your intake and exhuast vents are not froze up(or obstructed in any way) on the outside of the house. Next, clean drain hoses, ports and trap, also clean the port where the pressure switch hose hooks to the draft inducer, and also the one where the other pressure switch hose hooks to the heat exchanger. Do these things and let us know what you find.

Gentlemen-I can't thank you enough. Your skill and expertise has guided me to the problem and, more importantly, its solution. I have a warm house once again thanks to you. Indeed, the pressure switch was the problem. It's limping along now but tomorrow I know what to buy and replace. Thank you so much!
Doug