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.