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- Adjusting the boiler temperature can help, but reducing it too much is dangerous
Adjusting your boiler flow temperature can save up to £57 a year on your gas bills, but turning it down too low can be dangerous.
If you’re not sure what your boiler’s flow temperature setting is, you’re not alone.
In short, it is a way to adjust the temperature of the water that comes out of your boiler.
Many people don’t even know this setting exists, and many more are reluctant to change their boiler settings in case they do something wrong.
But changing your boiler flow settings is a simple process that can save you up to £57.04 a year on your energy bills, according to research.
Most boilers have flow settings between 70°C and 80°C when first installed. This can be much hotter than necessary to perform tasks such as heating radiators.
Let it flow: Adjusting your boiler’s flow temperature can help save money on your energy bills
An EDF statement said: ‘At lower flow temperatures, the combi boiler is more often in condensing mode. This means it can capture more heat and recycle it back into the system.”
Reducing your combi boiler’s flow temperature to 50°C can mean cutting up to 8 per cent off a typical home’s annual gas bill, according to a study published by the Heating and Hot Water Industry Council.
The typical annual gas bill is £828.70, made up of £713 in gas and £115.70 in ongoing charges.
That means adjusting the flow temperature could mean savings of up to £57.04 a year.
However, this should be done with caution.
Setting the temperature too low can encourage the buildup of harmful bacteria such as Legionella pneumophila, which causes Legionnaires’ disease.
Some experts think that 50°C is too low and to keep central heating systems more hygienic by ensuring boiler flow temperatures are kept above 60°C.
Ryan Gill, senior technical surveyor at boiler expert Boxt, said: “With the weather getting colder, trying to work out what setting to set your boiler to while still taking energy bills into account can be confusing.
‘You can lower your boiler’s flow temperature and save money without compromising too much on comfort; However, it is important to note that the optimal temperature for your boiler will generally depend on the brand and type of boiler.
‘For example, the flow temperature of combi boilers should not be set below 55°C. For those who have system or standard boilers with independent hot water storage, it should be kept at a minimum of 60c.
‘If the temperature is set below these levels, it may encourage bacterial growth, which could pose a potential health risk to you and your family. Furthermore, if the supply temperature is too low, the radiators may not heat the house adequately.’
That means that the savings mentioned above by reducing the boiler flow temperature may not be safe in practice.
Any savings may also vary, for example due to the efficiency of your boiler.
How to adjust the flow temperature of your boiler
On traditional boilers with a hot water cylinder, there will only be one setting to adjust to change the flow setting.
On smaller combi boilers you will probably have two settings, one for hot water and one for radiators.
You may not be able to set the flow rate to a specific temperature as your boiler may have a different design, for example a dial with temperatures from one to six.
If in doubt, consult your engineer next time you carry out an annual boiler safety check.