Also, when you work on the control board, you HAVE to remove the Spark electrode orange cable connection. If you do NOT use a back up to hold the Piezo in place when removing that spade connection you risk breaking loose the soldered connection for that Piezo tower on the circuit board. One result of loose/broken solder connections is either lack of spark(weak spark) OR lack of flame sense because of the loose intermittent connection due to the solder. If you can "wiggle" the Piezo tower on the board, remove the board and resolder the Piezo connections. Doug