Necht dishwasher wqp12-9319 error code E4?

My Necht dishwasher has an error code of E4 showing and will not seem to re-set. When switched on the machine sounds as though it is draining water though there is non in it. on the last cycle used the machine flooded what i think was a small amount of water of what i could see. I dont use tablets and i have re-filled the salt section. Could anyone advise me on the next move. I am begining to be rather concerned as the comments regarding Necht products are very negative. We have just moved into a new home and the kitchen appliances are all Necht. (poor us)