We walked through northern Spain this fall, and we noticed many places we stayed only had their heat on in the evening for a few hours and then turned it off (say, 7-11). Also, the heat was not central but came from a radiator without vents in the room.
Given the cool, humid/rainy weather and lack of vents, that meant the room was very cool and clammy most of the time. A real problem if you washed clothes and had to let them air dry (as we had to do in most places due to the lack of dryers).