Lowering the boiler flow temperature will make the radiators run cooler, but should not affect the overall temperature in the room, which is based on the thermostat levels. Industry experts say households may need to use trial and error to find the level they are comfortable with, but caution against particularly vulnerable groups using this approach. Octopus Energy, which advises its own customers on reducing the supply temperature, recommends setting the temperature of combi boilers to 50 C for heating and 55 C for hot water. Combi boilers are those that heat both hot water and radiators, without a separate water cylinder. For those with boilers and a hot water cylinder, he recommends setting the flow temperature in the boiler a few degrees above 60C for heating and hot water and setting the temperature in the hot water cylinder at the same level, to protect against Legionella Bacteria. A government spokesman said: “We are investing a total of £6.6 billion this Parliament to improve energy efficiency across the country, with the majority of our support targeting low-income people and vulnerable households. “Immense progress has already been made, with the number of homes rated C and above at 46 per cent and rising, up from just 14 per cent in 2010. “This benefits tens of thousands of homes and delivers an average saving of £300 a year on energy bills.”
