My two situations:
1- Here in Bologna we have gas fired centralized heating for all the condo (120 flats) with underfloor coils, the temperature is set at 20-21°C from the first of october to the first of may, non stop. This cost 2400 euros per year. No attention required, we don't even have a thermostat, the temperature is kept constant by varying water flow and temperature automatically.
2- At my parents we have a condensing combi-boiler installed in 2001 rated at 21kW, the efficiency is around 105% of the LHV, impressive isn't it?

It both provides hot water at 55°C (currently set at 12 litres/minute plus an integrated storage of 60 litres used for the water circulator to have instant hot water, activated by the light switch in the bathroom and an additional switch in the kitchen) and space heating via radiators with the water temperature automatically set by an outside temperature sensor. Indoor heating is kept at 18,5°C.
The annual expense is around 1000 euros for 8 hours of heating a day + hot water (in summer we use solar collectors) from late october/early november to mid-april.
Now a personal question, I wish you can answer!
It seems that American installations are way less refined than those put in operation in Italy, I wonder why is that. Over here all the pipes are laid down in the walls (even in retrofitting) and are all wrapped in insulation on an incombustible surface, as an example the wood board would to which all the stuff is connected in the last photo would be illegal over here! And malpractice in all the other cases, also flexible plastic piping is not used for permanent connection and copper or pvc are the materials of choice.
I'm not saying that it's not good but I'm just wondering how one can tolerate such intricate systems for something that easily can be made invisible.