Check from the main board on the blue 6 pin connector at pin3 gray wire to pin6 black wire for resistance reading of the steam generator thermistor. You can also check at the steam generator connection on the 10 pin connector at pin1 gray wire to pin6 black wire. You can also check directly at the thermistor gray wire to black wire. If you read 5 Vdc then the thermistor is defective and needs to be replaced. If you read 0 Vdc then the main board is defective and needs to be replaced.