As January brings colder temperatures, many of us are relying heavily on central heating and radiators, which naturally leads to higher energy consumption and rising bills. With Ofgem’s latest price cap update in October 2025, the average dual-fuel bill has climbed from £1,720 to around £1,755 a year, intensifying the financial pressure on households.
However, experts from Which? have shared a valuable tip on TikTok that could help you save money by adjusting your radiator valves correctly. Their recommendation: never set your thermostat valves and dials above three—unless it’s the room containing your main thermostat.
“Setting the valve to five opens it fully, allowing a large volume of hot water into the radiator whenever your central heating runs,” Which? explains. While this might warm a room faster, setting every radiator to five can cause your heating bills to soar unnecessarily.
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“In bedrooms, keep the dial between two and three,” Which? advises. “This maintains a comfortable temperature range of 15 to 20 degrees Celsius and helps reduce energy costs.”
If you plan to be away from your home for an extended time, the advice changes. “Set the thermostat valve to the frost symbol,” Which? recommends. This setting lets enough hot water circulate to keep the room above seven degrees, preventing pipe freezes without wasting energy.
Beyond valve settings, the placement of your furniture can also impact heating efficiency. Matt Oberle, an energy expert from Utility Rates, highlights that moving your sofa away from the radiator could save you hundreds on your heating bill.
“Heat circulates by warming the air around radiators, which then rises and spreads throughout the room,” Matt explains. “A sofa placed directly in front of a radiator blocks this airflow, causing the heat to be absorbed into the furniture instead of heating the room. This forces your heating system to work harder to reach the desired temperature.”
He adds that sofa material matters too. “Dense fabrics like leather or thick upholstery absorb and retain heat, acting as a sponge and reducing the heat that enters your living space. This inefficiency wastes both energy and money.”
By making these simple adjustments—correctly setting your radiator valves and rearranging your furniture—you can improve heating efficiency and potentially lower your winter energy bills significantly.