My mother in law has a Whirlpool ADP 903 which has worked flawlessly for several years. However a couple of weeks ago it suddenly failed to start. The green power light is on. there is no sign of it wanting to fill and it will sit like that quite happily for hours. No flashing lights nothing. It emptied properly on its last use, water is getting to it and I am at a loss as to the cause. Any suggestions will be most gratefully received.