Halfway through my shower this morning there was no more warm water. I checked the central heating (which also takes care of the warm water) and I couldn't find the problem. Called the dealer who (surprisingly on Boxing Day which is a public holiday here) came within an hour and concluded the entire installation is broken beyond repair and needs replacement. They can do it on Monday and it will cost €2.5K - yuck...Of course this happens at the beginning of a major cold spell here with temperatures well below zero. Must find a way to keep warm until Monday.
Christmas dinner was nice though stressful. Cooking a 5 course dinner for 9 is quite some work, but all food and drinks were well received and we had a great day.