Set my Diplomat ADP8322 to usual 50deg wash and it seemed to start off ok but after aprox 30 mins, started a high pitched beeping alarm which only stopped when power switched off. Water had been going through ok but not heating up as the detergent tablet was not disolved and dishes were cold and looked like they were rinsed but not washed clean. Did all the usual checks, (spray arm, cleaned filter, checked salt container etc) and have tried again but no joy! The machine is around 5 years old.. can anyone help please???