my furnace is blowing cold air. Last night I noticed that my furnace was shuting off when the thermostat read 64 degrees. But we had the therm. Set to 70 degrees. Now today it is only blowing cold air I have tried turning it on and off again to spark some flame? That did nothing. Now the furnace will only start by making a little sound as if its starting up for about one minute then it kicks on blows cold, then shuts off. I don't think it's a thermostat problem because it responds to me controlling it manually. My guess from other people having what's seems to be the same problem, as being the ignitor. Please help its only 5 degrees here tonight. But I am lucky to be in a condo where I have other units above below and around me! So it does not go below 58 degrees.

Also note it just dropped down to the coldest it has been all year last night when this all started. It was 8 degrees and our furnace is out off our deck (porch) and is not well insulated in the room it is in. Can get as cold as it is outside! Please help thank you.