The Anna heater is beautifully designed and powerful. Unfortunately, mine gave up the ghost after one season. I was too annoyed to pack it up and send it in and then bought Anna Little, as the lower output was enough for me anyway. Anna Little has been running without complaint so far :-)
If it has not blown the fuse, the heater is almost certainly defective.
It should only switch off if the fan openings are covered and therefore overheats.
Hello Swissjoker - Since I am also a customer, I cannot answer this question for you - However, since I bought my device 2 years ago, I assume that I am not "to blame" for this misery.
In principle, any room up to 25m2 can be heated effectively. In larger rooms, the temperature may never reach the desired target, but of course it will still be warmer.
The unit has two heating levels (1'200, 2'000 W). The consumption is 99% identical to the heating power.
I don't see any problems there. We operate the unit by simply plugging it in. It then immediately starts to run at the set temperature. Of course, adjustments can be made at any time. By the way, we are completely satisfied with the Anna.