That looks to be a pretty well-built, high-quality machine. I think if you replaced it you would be hard pressed to get another 15 years out of the new one.

Perhaps you might try checking the air-pressure activation of the easily accessed water pressure valve, possibly replace it, and if that doesn't solve the problem, you might see if you can find a used control module, also easy to get at. You wouldn't have too many euros invested at that point, and it might well fix the machine for another 15 years.

tanstaafl.