You should start by checking if the flow temperature is set correctly Many EU gas boilers are set too high, such that the boilers don't operate in condensing m

You should start by checking if the flow temperature is set correctly Many EU gas boilers are set too high, such that the boilers don't operate in condensing mode. You could save 6-8% gas by doing this: https://www.theheatinghub.co.uk/articles/turn-down-the-boiler-flow-temperature https://www.theheatinghub.co.uk/articles/turn-down-the-boile... Octopus Energy has some further tips: https://octopus.energy/blog/winter-workout-gas-saving-tips/ https://octopus.energy/blog/winter-workout-gas-saving-tips/