Ignis ADL349 dishwasher stops after 5 mins. normal operation? ?

Ignis ADL349. Unit had obstruction in pump which I removed. Dishwasher now operates normally....for about five minutes then warning alarm sounds. Machine can be reset and restarted and operates normally......Yes for five more minutes then warning light flashes constantly and alarm sounds until it is reset. Have tried a new pump just in case it was damaged by previously removed obstruction but same symptons exist. Any help would be greatly appreciated!!!!!!!!