We have the equipment now about a month and there is nothing to complain about.
The service is good. I asked for the bill as a PDF file and received the same day a reply to the statement.
In addition, we received a credit for the energy-saving device of our utilities ;-) for the A +++.
Two negative points I would still want to address what has nothing to do with the technical condition of the product and why I still have given 5 stars.
The delivery was made only 4 working days after delivery. We were given one day after the delivery date of forwarding a letter, which we then made up the time of delivery. Perhaps we should speak there early with the shipping company or the seller, if you are in a hurry with the delivery. Since we still had our old equipment in use, were the few days no problem for us.
The second is the packaging, or much more of a foil which is glued around three sides of the device. She is very thin and in some places a little hard abzubekommen (much Knibbelarbeit).