Do you have a combi boiler? Cut your energy use by simply adjusting your boiler settings

Did you know you could cut your gas use by an average of 9% by changing a single setting on your boiler? 

Read on to find out how to make the change and about the benefits.

Project partners, Nottinghamshire County Council, invested £150,000 in to this scheme, which forms part of their Cost of Living support programme for residents.


The scheme focused on reducing the flow temperature to a minimum of 60°C which enables the boiler to go into condensing mode and therefore operate more efficiently as less gas is required to heat the water. 


Please note, this scheme is now closed for home visits, in which we worked with Nottinghamshire County Council to assist vulnerable households run their boiler more efficiently.


The scheme was a great success and we’re pleased to share the final figures below:

Home visits completed
Average saved per household
tCO2e per kWh year on year carbon reductions

Even though the scheme is now closed for home visits, you can still follow our handy guidance to make the change yourself. It is quick, easy and will help cut some all important costs.

Click the button below to follow our handy step-by-step guide on how to make the recommended setting.

The form explains how to change the flow temperature for each type of boiler and allows us to measure how many people are making a positive impact by lowering their carbon.


Watch the demonstration video below

Frequently Asked Questions

A condensing combi boiler heats both your water & your central heating all from the same unit. They can be identified by 5 copper pipes coming out the bottom of the boiler. 

By reducing the flow temperature, you will be using less gas to heat your home because you will be heating the water that flows between the boiler and the radiator to a lower temperature.

Most boilers have an 80/60 flow and return temperature, sending a temperature of 80°C to your radiators, giving off 20°C to heat your home and returning 60°C to your boiler. By reducing the flow temperature, you can achieve the same effect without losing that 20°C.

Don’t worry, this doesn’t affect the temperature of your hot water and doesn’t mean you will have to take cold showers, it means that you will be setting your boiler into ‘condensing mode.’

Condensing mode is when the boiler starts to recover its lost heat, running more efficiently. This means that you will be setting your boiler to run at the efficiency rating that many modern combi boilers advertise.

Reducing the flow temperature can achieve significant carbon reductions and lower running costs by an average of 9% on gas bills without losing warmth. Based on Ofgem’s average energy bill of £3549, of which £2,220 will be for gas.

You shouldn’t feel a difference. Your radiators may feel cooler to the touch, but this is because the water being sent to the radiators is cooler. The radiators will still heat your home effectively; it may just take a little longer. For many, this is not a noticeable difference and can be easily resolved by setting your heating to come on 15-30 minutes earlier than before.

Below you can view or download the Let’s Optimise your Heating booklet for your reference.

Over 15 million households in the UK have a combi condensing boiler – if we all work together to turn down our boilers, then we can make a huge difference during a time when we are hoping to reduce our energy bills, lower our energy use and prevent energy loss.

This scheme is funded by: