British Gas, EDF, EON, Ovo, Octopus customers urged to lower boiler flow temperature before July 1

Customers of major energy providers British Gas, EDF, EON, Ovo, and Octopus are being encouraged to lower their boiler flow temperatures before July 1. The boiler flow temperature refers to the heat level at which your boiler warms water before it circulates through your radiators.

As the heated water travels through the radiators, it cools down and returns to the boiler at a lower temperature—known as the return temperature. Lowering the flow temperature reduces the return temperature, making your boiler operate more efficiently, which helps you save both energy and money. This advice arrives just in time before the next increase in the energy price cap.

Octopus Energy highlights that the default flow temperature setting is often higher than necessary. By turning it down slightly, your home can remain comfortably warm while potentially cutting energy bills by up to 12%, saving as much as £87, according to Nesta.

Recommended settings differ depending on your boiler type: for combi boilers, a flow temperature of 50°C for heating and 55°C for hot water is advisable. For boilers paired with hot water cylinders, setting the flow temperature a few degrees above 60°C is suggested, with the cylinder thermostat set to 60°C. Typically, the cylinder control is located about one-third of the way up the tank.

Stephen Day, a Gas Safe Engineer at iHeat, advises how to adjust these settings: locate the flow temperature control dial or digital panel on your boiler, often marked with a radiator icon. If numbered, set it to 60°C; if unnumbered, use the midpoint as a guideline. After making adjustments, monitor your home’s warmth and fine-tune as needed. If your boiler is linked to a hot water tank, it’s best to consult a professional before changing settings to prevent any complications.

Taking these steps can help improve boiler efficiency and ease the impact of rising energy costs this summer.