All UK households told to make 1 boiler setting change to cut bills in December

A Gas Safe Engineer says adjusting your boiler’s flow temperature can cut gas bills by up to 9%, and your home will stay just as warm. You just need to make a simple boiler setting change

If you’re aiming for a cosier home and reduced bills this December, a minor adjustment could make a significant impact. Patrick Garner, a Gas Safe Engineer at Heatable, suggests that many households are unaware of a particular boiler setting that could be a game-changer for their finances.

Every boiler has a flow temperature, which is the heat of the water exiting your boiler before it circulates around your radiators. It’s crucial for efficient heating, but one straightforward tweak can do wonders for your home’s warmth and your energy bills, and it’s incredibly easy to put into action.

Patrick cautions that most people have their boilers set far too high from the factory, often around 75°C to 80°C, which can lead to several issues. However, a simple adjustment can help save you a substantial amount of money.

Why it matters

When a modern combi boiler has a flow temperature of around 60°C, it operates at its most efficient condensing mode. This is because the boiler utilises more heat from the gas it burns.

You can also reduce your gas usage by up to 9%, saving on average around £100 per year. The best part is that you won’t feel any chillier.

Patrick clarified: “The house will feel just as warm. Your radiators will heat up a little slower, but they stay warm for longer and keep the temperature steadier. You lose that intense ‘blast’ of heat that wastes gas, and most people won’t even notice it.”

What happens if it’s too high or low?

If you crank your boiler up too high (typically above 75°C), you risk wasting energy, overheating your radiators and the boiler switching out of condensing mode. The rapid change in temperature can also result in a home that feels less comfortable.

Too low (below 50°C), and you may find it difficult to heat your home in cold weather. This can also be problematic in older and poorly insulated homes.

What is the ideal temperature?

Combi boilers should be set at around 60°C on the flow temperature. Patrick suggests that system or conventional boilers are best set at 65°C for heating and at least 60°C for hot water, as this still safeguards against Legionella.

But that’s not all, as Patrick also has three quick checks you can do this December. They include:

1. Pressure – your boiler should sit around the 1 to 1.5 bar when cold. If it drops below this, it needs topping up.
2. Heating schedule – timers can be used or smart thermostats to ensure you’re not heating up an empty home.
3. Insulate exposed pipes – foam lagging for pipes and a jacket for hot water cylinders reduce heat loss. It also helps if you insulate the outdoor condensate pipe to avoid freezing and causing breakdowns in winter.

Patrick’s primary advice, however, is to implement the simple boiler setting change. He stated: “A tiny twist of the dial is all it takes to stay warm for less this December.”