Millions of UK households could reduce their annual energy bills by roughly £57 simply by spending a few seconds adjusting their combi boilers, according to research foundation Nesta.
Many condensing combi boilers are configured to send water to radiators at 75C or 80C, but Nesta estimates that lowering this central heating flow temperature to 60C could trim a household's overall gas consumption by approximately 7%.
How the adjustment works
The boiler flow temperature is the temperature to which the boiler heats water before it is distributed to radiators. As the water circulates through the radiators, it cools before returning to the boiler, and the temperature at this stage is known as the return temperature.
Reducing the flow temperature can cut wasted energy, and the check is completely free and straightforward to carry out.
Guidance from the Energy Saving Trust
The Energy Saving Trust advises that combi boilers without a hot water cylinder typically have two dials or settings, one for radiators and one for hot water. Householders should adjust the radiator setting, which may be indicated by a radiator icon rather than a tap.
Experts advise: "Before you make any adjustments, it's a good idea to take a photo or make a note of how everything's currently set. That way you'll know what to turn it back to if you need to."
They add: "If the weather is mild and you have a combi boiler, you're more likely to be able to heat your home with a lower flow temperature, maybe 50 or 55 degrees. When it's very cold, you'll want to set it a bit higher."
