Smeg d/washer DI612 E8 fault

hello,had a look at this d/w which iv been assured shows the E8 fault,which i see is alternate washing valve,as it happened d/w worked fine when i checked it,altho the machine had a fairly low reading but doesnt trip,which i couldnt pin down,it has since thrown up same fault,any ideas would be great before i go back,thanx