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How to save cash with a single change to your boiler settings

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

Boiler owner turning down their flow temperature to 60 degrees
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people say they have turned down their boiler flow temperature

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 people taking transatlantic flights.

Why should I do this? Reasons to join the money saving boiler challenge

Save on your gas bill

Turning down a single setting will make your boiler work more efficiently, saving around £65 a year for the average household.* *Based on energy prices as at September 2023.

Reduce carbon emissions

The average UK gas boiler produces about the same carbon emissions in a year as taking seven transatlantic flights. Take this simple action to reduce energy waste from your home.

Tell friends and family

There are more than 15 million homes in the UK with a combi boiler. If we spread the word and work together to turn down 10 million boilers we could save 1.7 million tonnes of carbon emissions.

Why does this matter?


Many combi boilers are burning more gas, generating more carbon emissions and costing households more than they need to. People could be saving energy and money simply by ensuring their boiler is running as efficiently as possible. But many people aren’t aware they can change their boiler settings. 

The average household could currently save around £65 per year on their heating bill by lowering their boiler flow temperature.* Heating homes with fossil fuels accounts for 15% of the UK’s carbon emissions. So by using energy more efficiently, we can cut carbon emissions and save money on our heating bills at the same time. 

*Based on energy prices as at September 2023.

Frequently Asked Questions

  • How does it work?

    Combi boilers work best when they heat the water that goes to the radiators at 60°C or below (this is called the ‘flow temperature’).

    Most boilers in the UK are set at flow temperatures much higher than 60°C (often 70-80°C)

    A flow temperature of 60°C means your combi boiler will be in condensing mode. When your combi boiler is in condensing mode it will recover heat that would otherwise be lost so that it runs more efficiently.

  • What is boiler flow temperature?

    The flow temperature is the temperature that a boiler heats water up to before it goes around the radiators in your home. 

    Changing the flow temperature on a combi boiler will not affect the temperature of the hot water from your taps and showers.

  • Can I do this if I have a hot water tank?

    Unfortunately we’re unable to suggest that you reduce your boiler flow temperature if you have a water tank.

    Our guidance doesn’t currently cover central heating systems that have a hot water tank. You can read more about this at

Nesta campaign blog

How we used a testing lab in Salford to identify the effects of changing boiler flow temperatures

Find out where we tested the effects of turning down boiler flow temperatures

Change your boiler flow temperature throughout the year to save more money

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