For several days - have been manually powering down then restarting sometimes catching on the first second or third ignite, trying to fix the furnace and save the kids some money... today it died... will not ignite.. have sanded the flame sensor... cleaned every connection possible... Today furnace did not reach the requested temp... shut down... and could not get furnace to ignite again... HSI glows and looks like it works... how do I check if HSI is up to par?? Very frustrated at this point... could the control board be bad?? This is my sons house and has two babies really need to get the furnace working... thanks to all... help... getting cold in Michigan

If the ignitor glows, you can bet it's OK. Look for a clear plug in the blower access panel with a blinking LED inside. Count the blinks, then look at the label inside the panel for translation. Post back.

KC13 - thanks for answering... sorry for not responding sooner but I've been down at the sons house trying to get the furnace running... today I replaced the circuit board and got the furnace back to the original issue... igniting on the first second or third try... this lasted about 5 hours same as yesterday... then stop working again... the igniter glows you here a click and does not ignite... the igniter glows bright... is it possible it's the gas valve?? I have not noticed a clear plug-in the blower area... I will check tomorrow when I go back --the kids and baby's are staying here tonight.. again thanks for your help... the only LED light I've noticed on the furnace is on the control board (circuit board). And the only message is one blink --- which means failed to ignite three times.. which shuts down the furnace... you have to turn the furnace off then on to start again..

A voltmeter would reveal the problem. Is the click you hear from the gas control, or the gas control relay on the circuit board?