- on the furnace controller board, does the flame sensor(orange) get connected? what pin number on the 9 pin connector, the wire popped loose so the main burners are not get- ting lit? could the flame sensor be the problem? Thanks. Tshooter32
some controllers do not use the flame sensor wire, they use the ignition wire to sense. You need to know what manufacturer and the wiring schematic, but I have found that an additional ground is quite helpful from the burner assy. to the controls.