We got heating problems, reported it, got a first fix, that didn’t solve the issue. We then said that in a message, but then he didn’t get back until the last day. Apparently the boiler was turned off (not in the apartment as far as I could see) - and this is what I suspected. The last day the owner finally came, fixed it (we were out, so I didn’t get to see where), and the apartment was pleasant and warm, but not the first many days. We had to search for extra linen and blankets (but 2 of us still got a cold).
That was a big pity, I sense that the owner was surprised as well, but I did message on this…
Otherwise Prague is beautiful and the apartment is right in the center, on the left bank which is a most pleasant place to be.