its up to you in the long term but if it is a relay and you can solder we are only talking about £5
At that price its worth a punt, It may just be a bad solder joint on the relay, get that a lot on early Bosch dishwashers
As a long shot have you checked the wiring. Some dishwashers have a habit of breaking wires at the bottom of the door due to the bending as the door opens and closes
If you have to go to smeg for part then it get expensive
Dave