Air-to-water heat pump systems operate at lower temperatures than gas boilers. Heat pump temperatures are around 35oC to 55oC, while a boiler is nearer to 70oC or 80oC. This difference doesn’t impact how warm your home will be, but the heat pump’s lower temperatures mean that it can take longer for it to warm a space from cold quickly, which uses more energy.
As a result, it’s much more energy efficient to run the heat pump continuously, using your controls to gently ‘set back’ temperatures at night. For instance, you could set the daytime temperature to 20oC to keep the house warm, but at night this can be reduced to 17oC to 18oc. In the morning, the temperature can gently rise again, without impacting the efficiency of the system.