woke up this morning to find temperature at 16 degrees so i checked the furnace and found it not lit. it has an automatic ignition system so i raised the temp to get it to kick in but nothing happened. i have had the ignitor replaced twice in the past year and a half. anybody have any suggestion as to what i should do or look at next. when i raise temperature it makes a humming sound but no clicking sound like its trying to ignite. i followed the steps outlined a couple of threads ago but still nothing. it is a Coleman t.h.e. 90 furnace. read about these flashing lights for fault code on furnaces but couldnt find any.