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Fancy £150 Off Your Heating Bill, For Five Minutes Work?


Turning down the flow temperature on your combi boiler to 60°c or below can knock £££ off your heating bill each year and reduce energy waste from your home


Turning down the flow temperature on your combi boiler to 60°c or below can knock £££ off your heating bill each year and reduce energy waste from your home.

Many combi boilers are burning more gas, generating more carbon emissions and costing households more than they need to. People could save energy and money simply by ensuring their boiler runs as efficiently as possible. But many people aren’t aware they can change their boiler settings. Did you know that your combi boiler can be made to run more efficiently and that this could save gas, therefore saving you money?


The boiler flow temperature is the temperature of the water that is sent to radiators by the boiler. Combi boilers reach the highest levels of efficiency when the water that heats the radiators returns to the boiler below 55 degrees. Most boilers in the UK are set at temperatures above this, with the average temperature of water to radiators being around 70 degrees.

Whilst reducing your boiler to a 60°C flow temperature could reduce your gas usage by around 9% (leading to a saving of about £112 a year for the average home), lowering the flow temperature to 55°C could save even more. The table below sets out the saving, measured at a testing site, Salford Energy House, at different flow temperatures.


If 10 million households turned down the flow temperature on their combi boilers to 60°c or below this could wipe £1billion off UK energy bills and save 1.7 million tonnes of carbon emissions – the equivalent of nearly six million transatlantic flights.

A 12% gas saving could equate to around £150 off the average annual gas bill. Some poorly insulated households may find that 55°C radiators are too cool for their home when it’s very cold outside. When the radiators aren’t warm enough to heat your rooms, it may take a little more time to heat the room and may not reach the temperature the thermostat is set to.


In warmer months, you can make more significant savings by lowering your flow temperature (e.g., down to 50°C). For example, you could set your flow temperature to 50°C in October, raise it to 55°C in November and then raise it to 60°C on the coldest days of the year. This way, you are making more significant savings on the warmer days. Changing your boiler flow temperature settings multiple times over the year is safe and easy.


The best way to determine what flow temperature works for you in different seasons is to try reducing the flow temperature in 5°C increments. Leave it at this new setting for a few days and see if you are happy with the temperatures of the rooms in your house. You can keep doing this until you find a temperature that works for you and your home.


If you have a modern “modulating” boiler, you can get a heating engineer to install a device that will automatically adjust your flow temperature. Two such technologies exist – called load compensation or weather compensation. Both will save energy in a similar way to reducing the flow temperature manually. These devices ensure that you are using a lower flow temperature when possible – without needing to make any changes to your settings manually.


The Money Saving Boiler Challenge, which is a scheme set up by Nesta (UK’s innovation agency for social good) to try and spread the word about how adjusting your settings to save gas and money, has an excellent walk-through to help you to adjust your settings, which you can view HERE, which will guide you on how to quickly and easy make the changes, and save some money.


If 10 million households turned down the flow temperature on their combi boilers to 60°c or below, this could wipe £1billion off UK energy bills and save 1.7 million tonnes of carbon emissions – the equivalent of nearly six million transatlantic flights.


The scheme is attempting to have 100,000 people change their settings to save energy costs, and nearly 70,000 have said they have already made the changes, so give it a whirl and let your friends know too; who doesn't need to save money these days!


If 10 million households turned down the flow temperature on their combi boilers to 60°c or below this could wipe £1billion off UK energy bills and save 1.7 million tonnes of carbon emissions – the equivalent of nearly six million transatlantic flights.



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