Boiler flow settings

You can cut your gas bills by 6-8% by lowering the flow temperature on your condensing combi boiler so that it heats water feeding radiators to 60°C, rather than the factory default of 80°C. You will notice that your radiators do not feel quite so hot – this is a sign that the system is running cooler and more efficiently. If you do not feel cold, then it is working as it should.

You may find it takes longer for your house to warm up – you can extend the time your boiler is on to compensate. For most homes, running the boiler for a longer period at a lower temperature will use less gas than shorter, hotter cycles of heating.

Check your boiler’s operating manual for how to change the settings. You should be able to find this online if you don’t have the paper copy.

Watch this short video on boiler tweaks to lower the flow temperature on a combi boiler

Image of a gas boiler with dials

Boilers with dials

Go to the dial with the little radiator icon next to it.

The dial may show numbers (1-6), a dashed line or a line increasing in thickness. Halfway or number 3 will be
about 55-60°C. Try setting slightly higher to begin with or number 3.

Image of a gas boiler with digital displays

Boilers with digital displays

Some boilers have a dial, but the temperature will show on the digital display. Turn the dial until the digital display shows 60°C flow temperature.

Image of a gas boiler with up and down buttons

Boilers with up and down buttons

Press the minus (-) radiator button until the digital display shows 60°C flow temperature. You may have to press and hold a menu button to reveal flow  temperature, then reduce to 60°C, then press the menu button again to set it.

Heating top tips

  • Turning your heating down by just 1°C could cut your heating bills by up to 10%. Try setting your thermostat to 18°C which should be a comfortable setting for most householders.
  • Setting your heating and hot water to come on only when required could save even more on your household bills.
  • Match your duvet to the seasons – use a low tog in summer and high tog in winter to avoid having to use the heating unnecessarily.
  • Layer your clothing to lock in body heat.
  • Plug-in electric heaters are expensive to run, so use heated throws where you can, as they are much cheaper to run to keep you warm.