Experts from Which? have shared important advice concerning your radiators this winter, explaining how the level your thermostats are set to dictates how much your energy bills are
As temperatures continue to drop this January, it’s likely you’ll be cranking up your central heating and radiators to keep warm. Of course, this leads to a surge in energy consumption and larger bills. Indeed, Ofgem’s new price cap, implemented in October 2025, nudged the average dual-fuel bill from £1,720 to around £1,755 annually.
However, experts from Which? have shared a piece of advice on TikTok that could help shave off some of those costs. They suggest adjusting the valves on your radiators so they’re never set above three – unless it’s the room housing your thermostat.
“Whacking your valve up to five opens the valve to the max, letting loads of hot water into the radiator when your central is heating on,” they advised in a video.
While this might be handy for quickly warming a room, if every thermostat is cranked up to five, you could find yourself facing unnecessarily high heating bills.
“In bedrooms, you should keep the dial between two and three,” Which? advised. “This will maintain the room temperature between 15 and 20 degrees, which is comfortable and could save you money.”
However, if you’re planning to be away from home for an extended period, the advice changes. Which? urged: “Set it [thermostat] to the frost sign.
“When your heating is on, this will allow just enough water into the radiator to keep the room above seven degrees so your pipes don’t freeze.”
Elsewhere, a second energy specialist has revealed that the placement of your sofa could potentially add hundreds of pounds to your heating costs.
Matt Oberle from Utility Rates explains that whilst numerous complicated methods exist to reduce household energy expenses, one of the most straightforward solutions takes mere seconds and costs nothing – simply repositioning your sofa away from the radiator.
“People don’t often think about it, but the way heat moves through a room is as much about physics as it is about boiler settings,” he said.
“Radiators work by heating the air directly around them, and that warm air rises and circulates throughout the room. If you’ve got a large object, like a sofa, pressed against the radiator, you’re essentially blocking that convective airflow.”
Matt continued: “The heat is absorbed into the furniture rather than being distributed evenly, which forces your system to work harder to reach the set temperature.”
He further explained that the impact can be more significant depending on the sofa type, noting: “Dense, dark fabrics such as leather or thick upholstery act like heat sponges.
“They soak up the energy your boiler is generating and hold it in the material, instead of letting it move into the living space.”
He closed by stressing: “From an efficiency perspective, it’s a complete waste.”