Page last updated on 22nd April 2026
Lowering your combi boiler flow temperature to save money
We’ve put together some helpful tips to help save energy around the home. On this page, we have teamed up with Nesta to show you that adjusting your combi boiler flow temperature from 80°C to 60°C could save you money each year.
What’s on this page?
- What is a combi boiler and combi boiler temperature?
- What temperature should a combi boiler be set at?
- Combi boiler savings: changing the combi boiler settings to save money
- How to change the boiler temperature?
- Is there help and advice for those worried about the rising costs of energy?
- How much could I pay to run household appliances?
Reducing your boiler flow temperature from 80°C to 60°C isn’t about making your house cooler; it’s about lowering the temperature of the water your boiler sends to the radiators in your home.
This makes the boiler work more efficiently, meaning you use less energy to warm your home to the same temperature.
Who is this energy saving tip for?
This advice is for people with a combi boiler, and who feel confident to make small adjustments to their boiler temperature controls. We will take you step-by-step through how to do this below, but if you don’t feel confident making these adjustments, you may want to consult the manual for your boiler or speak to a professional heating engineer/technician.
What is a combi boiler and combi boiler temperature?
A combi boiler, short for combination boiler, is a type of heating system that provides both hot water and central heating from a single unit. Unlike traditional boilers, which require a separate hot water cylinder or tank, combi boilers heat water directly from the mains when you turn on a tap, ensuring a constant supply of hot water.
A combi boiler’s flow temperature is the temperature of the water that is sent to the radiators. Adjusting your combi boiler’s flow temperature can impact how efficiently your boiler works, which influences how much energy is used.
What temperature should a combi boiler be set at?
Nesta suggests that the best flow rate temperature for combi boilers is typically around 55-60 °C.
How does changing the combi boiler flow temperature save money?
Combi boilers are most efficient when the boiler flow temperature is around 55-60 °C as this sets the boiler into ‘condensing mode’. Staying in this setting for longer ensures your boiler is working at its most efficient level.
How to change boiler flow temperature
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Before you start
Consider taking photos of the settings of your boiler controls to help you reset them if needed.
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Are there vulnerable people in the household?
Please be aware of any people with underlying health conditions or those who may be vulnerable to cooler temperatures for other reasons. Reducing the combi boiler flow temperature may mean rooms take a bit longer to reach the desired temperature. You could consider reducing the combi boiler flow temperature and seeing what impact that has.
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Check if you have a combi boiler
This energy saving tip works for gas-powered combi boilers only. If you heat your home using another method then this guidance cannot currently be used. If you have a hot water tank, this means you have a system boiler, not a combi boiler, so this advice will not apply.
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Look for the radiator symbol
Ensure the dial has a radiator symbol next to it, this represents the heating system. It will normally look something like this...
If this symbol is next to a button, press the button and this should select the boiler flow temperature.
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Adjust the controls
This tip doesn’t involve adjusting your thermostat or your smart meter in-home display, it requires you to adjust the controls on your boiler itself.
- Open the front panel on your boiler.
- Ignore any timer-based controls you might have on your boiler.
- You may see a single dial or multiple dial control system, something like this…
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Change the temperature to 60°C
If you have a digital display showing the flow rate, you can adjust the controls to approximately 60°C.
Controls with a digital display will have a screen with a number to show you the temperature which is set. In most cases, setting the control to around the 12 o'clock position will bring it to 60°C.
If your flow temperature is already set to below 60°C, this is already likely to be the ideal boiler flow temperature for you, so we recommend not adjusting the control.
Your digital display may instantly update to the new flow temperature as you make the change, or update the next time the heating comes on.
If you don’t have a digital display and there is no way of knowing the exact flow temperature, you can try adjusting the controls to around the 12 o’clock position (see image below).
If your boiler controls have buttons, not dials
You will normally need to press the button to control the flow temperature. You will then have to adjust the flow temperature by using the plus and minus buttons to reach the target temperature of 60°C.
Once the selected temperature is reached, you may have to press the OK or radiator button again to confirm your selection.
Is there help and advice for those worried about the rising costs of energy?
Yes, if you are worried about the rising cost of energy and being able to pay your energy bills, we have information on the support and help which may be available.
Find out more about the support available from the government including energy saving tips on the GOV.UK website.
Looking for more ways to save? Try more of our smart energy tips like turning down your thermostat by 1°C and reducing your shower time to 4 minutes to see how much you could save.
How much could I pay to run household appliances?
The appliance energy calculator below will show how the price cap change could affect the cost of using everyday household appliances. Simply update the drop-down buttons with your estimated usage to see the costs.
The energy calculator below will show how the price cap change could affect the cost of using everyday household appliances. Simply update the drop-down buttons with your estimated usage to see the costs.
The calculator below will show a cost estimate for the current price cap (April-June 2026), and compare that to the previous price cap (January-March 2026), and the price cap before that (October-December 2025). So, you can see how your energy bills might have changed over time.
Please note: The electricity used by domestic appliances can vary depending on make and model, so we’ve used average power ratings. We have also used the price cap figures for a standard variable rate, so this calculator doesn't take into consideration any fixed tariffs or additional costs.
This calculator was last updated on 01/04/2026.
How will the price cap increase affect my bills?
£39
Cost per month
Based on the current energy price cap
−£5
Compared to the previous price cap
(Jan-Mar 2026)
−£2
Compared to the price cap before the previous
(Oct-Dec 2025)
Our energy saving tips are courtesy of Nesta and Energy Saving Trust
It’s important that you use the energy you need to keep warm, safe and healthy at home. Please visit our trusted partners pages for more information on how to safely implement these tips within your home - Nesta and Energy Saving Trust.
Remember, by combining our smart energy tips you could save even more. Some of these tips include:
