I have replaced old furnace with new Trane XR80 6 years ago. Since then, I have to admit, I didn't spend too much time on maintenance, except I was replacing filters regularly. Occasionally, it would happened once or twice a month that ignition or burning would stop for moment and we would smell gas but it would turn back again and continue without any problem. However, this morning, ignition came on for couple seconds and turned off, while fan continued to blow. The error flush code (9 flashes) indicates: 'Check Ignitor Circuit and Line “N” to 24VAC”Common” voltage'. Looking through the schematic diagram I could locate Line and but no 24 VAC. In addition, even if find it, I have trouble locating on the furnace. And, even if find it, what 'Check Ignitor' means. To replace it? To clean it? BTW, it is snowing outside. :-)