Gas and Oil Home Heating Furnaces - Gas Furnace...Won't Start

I have a 13 year old Janitrol natural gas furnace that will not fire. The starter lights the pilot but after about 30 seconds or so the main burner never fires and the pilot goes out. All I have at that point is something that sounds like a fan running. This can be repeated over and over. This used to happen from time to time through the years but it would always light the second time around. Any ideas what may be the problem with this unit?

networker

Not an expert - but on my furnace the fan you are hearing is prab the "draft" motor. The gas will not ignite if the furnace does nor sense the air flow. This could be caused by a birds nest preventing the flow out the exhaust, or a faulty sensor.

the draft motor will start first, then the pilot so if your pilot is lighting then its a gas delivery problem. check to be sure the wiring is intact on the gas valve and that the pilot is positioned properly to ignite the gas coming through the burners. if it all looks ok but still wont fire off you will need to call a tech, dont try to mess with gas