Was the electrical installation carried out properly? Experiences?

hm

looks correct at first. if it runs in the empty conduit, all the better. if it were a defect, what would you want to do? apart from that, do you even have (still) a warranty?

The question is whether it is a hidden defect if you only realize when trying to replace the cables that they were not properly installed. But the matter is settled because the 12-core telephone cable is actually suitable as a Gigabit network cable :-). So I did not have to replace it.

The question is whether it is a hidden defect if you only find out that the cables were not properly installed when trying to replace them. But the matter was settled because the 12-core telephone cable actually works as a Gigabit network cable :). So I didn't have to replace it.

Absolutely sure? And if so, lucky you...and over what distance actually?

Really, really sure? And if so, lucky you... and over what distance actually?

So far I have networked 3 rooms. Living room (ground floor), guest room (1st floor; cable router is here - FritzBox 6490) and gallery (2nd floor). The cables come together in the basement and are connected there to a Cat6 patch panel. The network sockets and all cables used are also at least CAT6.
In the first step, I only wanted to get the living room connected to the router on the 1st floor, so I only connected both sockets in the basement at the panel. The media PC in the living room then had 100mbit, which it fully used in the speed test. To also get the gallery connected and later move the NAS to the basement, I then installed a gigabit switch in the basement and connected it to the 3 sockets of the patch panel. After that, the media PC in the living room and the work PC in the gallery each showed gigabit.
The speed test from PC/gallery to NAS/1st floor ran consistently at 111 MB/s.
Cable lengths: gallery PC -> socket: 15m CAT7, then I estimate a good 15m of telephone cable to the switch. From the switch about 10m of telephone cable to the 1st floor and then 5m CAT6 to the Fritzbox, Fritzbox to NAS about 1m CAT6.
I was quite surprised myself, but had already read beforehand that telephone cables often work better in practice than one would think in theory.

top Then that's fine, lucky you!