If you have a gas combi boiler, there’s a quick and simple appliance switch that will reduce your energy usage and cut your gas bill, according to the UK government. Every gas combi boiler has a setting called flow temperature . Many households can reduce this to 60C without making their home noticeably cooler.
What is flow temperature?
A central heating boiler works by heating water and circulating it round your home to radiators, which warm your rooms. Most homes have a room thermostat, which turns the heating on and off depending on the temperature of the rooms.
But your boiler also has a thermostat, which controls the temperature of the water it sends round the heating system. So the flow temperature is the temperature of the water your gas combi boiler puts out into your heating system.
Once the water has transferred its heat into your living space, it returns to the boiler at a cooler temperature, known as the return temperature.
Boilers work more efficiently if the return temperature is low, and reducing your flow temperature also reduces your return temperature.
How do I change the flow temperature on my boiler to 60C?
As mentioned before, the flow temperature control of a gas combi boiler is not the same as the room thermostat. It’s very easy to adjust the flow temperature on your gas combi boiler, and it takes minutes.
Most gas combi boilers have a flow temperature control. Check the instructions for your boiler to see which knob you should turn to adjust your boiler’s flow temperature. It’s often the control marked with a radiator. We recommend taking a photo before you turn the control so you know how to turn it back if you need to.
If you no longer have an instruction manual for your gas combi boiler, check the handy website Free Boiler Manuals.
Is it safe to reduce the flow temperature on my boiler to 60C?
Turning down the flow temperature on your gas combi boiler to 60C is an easy and safe adjustment to make. You don’t need any special tools to change the flow temperature, and you don’t need to call in a heating engineer: it’s just a case of turning a knob.
But households with elderly people, or people with a health condition that is made worse by the cold may find that they need their house to warm up faster. In that case, they may want to maintain a higher flow temperature of 65C.
What if I don’t like having a lower flow temperature on my gas combi boiler?
If a flow temperature of 60C does not work for you, then you can turn it back up again. Some households need to increase their flow temperature during times of very cold weather, or if someone in the house is unwell and particularly sensitive to cold.
What other steps can I take to make my heating system more efficient?
Moving items away from radiators can improve the efficiency of your heating. If you have domestic items that stop your radiators working efficiently, it may be better to move them into storage outside the home, such as a storage unit. Don’t forget that items stored outside the home may not be covered by contents insurance, and you’ll need to arrange separate self-storage insurance if it is not included in your monthly self-storage bill.
For more ideas about improving the efficiency of your central heating, see our blogpost.