I have an old Janitrol furnace, time for a new one, but... Goodman Mfg. GUPI075-3 There was a similar post, but didn't seem to finish discussion.. The Inducive Draft Motor comes on; the pilot lights, but the system will not ignite on its own. If I provide a small amount of airflow toward the burners, gas is immediately introduced and the system works normally. My suspicion is that the draft motor is turning too slow to provide proper airflow or there is a "flow sensor" i have been unable to locate. What component senses airflow to turn on the main gas supply? Thank you for any help!