As much as I would like to help you, I must emphasize that this forum is located in America. Most of us have had limited exposure to the Euro designs, however some of the other techs such as Brnt Toast might be able to help if they read this article.
You seem to be basing your question on conversations with various installers. This in itself is asking for trouble, since 90% of my service calls involve an appliance which had installation issues.
The solution to your problem is to do a Google search for the parent company and go to their website. They all provide Installation guides for their products and are happy to share them in hopes of getting aproper installation. I wish other installers would (or could) read them
btw, I like Peru a lot. Tried some of their "exports". Spanish is a second language here in Texas.