UK households can lower their energy bills and keep their homes cooler by making a simple adjustment to their boiler settings, according to gas safe engineer Patrick Garner of Heatable. The so-called European method involves reducing the hot water temperature and disabling pre-heat mode, which can prevent unnecessary heat release and gas usage.
How the boiler setting affects your home temperature
Even with the heating switched off, a gas combi boiler can still pump heat into the property when hot water is used. Every shower, hot tap, or washing-up session triggers the boiler to fire up, releasing small amounts of heat through its casing, pipework, and flue. This not only contributes to overall warmth inside the home but also means gas is being used continuously.
Patrick Garner explained: "Once the heating is off, hot water becomes the main thing still using gas. And in homes with several people showering every day, the cost soon adds up."
What to check on your boiler
First, ensure your boiler is set to hot-water-only mode. Leaving both heating and hot water enabled could cause the heating to trigger unexpectedly during a cold spell or due to a badly placed thermostat.
Next, check the hot water temperature on the boiler itself. For combi boilers, around 45°C to 50°C is typically comfortable for taps and showers. However, Garner warned: "Importantly, this only applies to combi boilers. If your home has a hot water cylinder, do not reduce the stored water temperature below 60°C to avoid the risk of Legionella."
Finally, check whether your boiler has pre-heat or comfort mode activated. This setting maintains a small amount of water at a high temperature inside the boiler so hot water arrives at the tap faster, but it causes the boiler to fire repeatedly throughout the day, even when nobody is using hot water. "Pre-heat mode constantly adds heat to your home and inflates your bills," Garner said.
Additional tips to cut costs
Leaving the washing up for one big wash at the end of the day can eliminate those brief bursts of heating that significantly contribute to your bills. Repairing any dripping hot taps can also help cut both gas and water bills.
Garner advised steering clear of needless upgrades. Solar diverters, for instance, only make sense if you already have solar panels, a hot water cylinder, and an immersion heater. They are of no use with a standard combi boiler.
He added: "You pay a standing charge of around 30p a day for being connected to the gas network, so you'll never get your bill down to zero. But a few changes can make a big difference overall."
