The most posible cause is that the ingiter have been mositure probably from a water leak and have be short the wires of the ingiter. Their is a small chance that it will dry by it self and be normal again. If not you can remove the top and reach for the ingiter, is a plastic box with a lot of wires in and out and with hair dryer you can try to dry it. If it still sparking again then you need to replace the igniter