Your flame sensor needs to be cleaned. It's the metal rod on the opposite side of the burners as the ignitor. There should be just one screw holding it in. Remove the screw, pull out the flame sensor. Brush it with a wire brush or piece of steel wool. Put it back in. That should stop the low flame sense code.my lennox model #c23-41wfc-1 wasnt working code flash showed burners failed to ignight.turned off power ,then on, it working now but showing low flame signal.what to do now?