"blowing the mains" isn't very informative. In your consumer unit (fuse box) there will be a big switch that shuts off everything, a similar big switch with a "test" button that protects all the sockets and a number of narrower switches that protect individual circuits.
So which one is tripping? My money is on the one with the "test" button. This trips if it sees even a slight "leak" of electricity to earth - say the metalwork of a dishwasher.
I would hazard a guess that if you find and cure the leak, you'll have solved the tripping problem.
You'll need to check hose joints inside the machine, any penetrations where heaters etc go and also any plastic tanks, enclosures etc.
It may be worth doing after Google searches for things like - say ' "Smeg dishwasher DI612CA leak" and see if there are any notorious problems and maybe how they were solved.