how long did you leave it? I have found that when you start Smeg dishwashers it really seem like it is never going to stop pumping and start filling ever. Must be at least 2 or 3 minutes
failing that i would look in the timer for shorted triacs
I have had the float stick on some of the smeg dishwashers as dave has said they do go through a re generation which takes a bit of time before they fill also look at the o rings on the salt chamber as these do leak with age