Hello, my best friend is selling his house and called me. Old Intertherm furnace cycling burner multiple times. Burner ignites then drops out. Inducer running and pressure switch made. I work on commercial equipment not much exposure to these units. No manual. No schematic. Acts as though not sensing flame. I see no flame sensor. I assume flame is sensed through the ignitor. Cant find any info on Nordyne site m/n G2RC-120A20. I leaning towards pulling burner and cleaning/inspecting. Not sure correct way to check flame signal on this unit. Propane furnace. Any help is appreciated….thanks all!