Comment by roel_v

Sure, if you have shitty insulation. The proper strategy is to have good insulation, and then to have the heat on constantly using a CV system at low temperatures, because heating constantly with water of 30 degrees (C, that is) is much more energy efficient than heating in peaks with much warmer water (60, 70, 90 even 20 years ago). So yes, in houses with crap insulation warming constantly is less efficient. However in properly build houses, warming constantly is more efficient. (I'm living for a few months in New Zealand - oh my the quality of the houses here is atrocious. It's one of the main reasons I couldn't live here permanently. And then they put in a 'heat pump' (an air to air one) and call themselves 'green'. Don't get me started.)