Is it better to set the programmer/timer to constant hot water (thus requiring just the occasional boost), or to time the hot water to come on/off as required (perhaps twice a day)? Is it best to set the temperature on the boiler at its highest during winter (when the central heating is in use) and, perhaps, reduce this in summer when only hot water is required? With gas bills set to rocket I would like to get the full benefit of the controls on my central heating system. What do you, the experts, have to say on this matter?