Financial guru Martin Lewis has issued a timely alert to households across the UK, urging them to adopt a simple daily routine to combat rising energy costs as winter tightens its grip.
The Crucial 4pm Rule Explained
The founder of MoneySavingExpert.com is advising people to follow a specific 4pm 'rule' to help reduce heat loss. With sunset occurring as early as 4.14pm, his team recommends drawing your curtains around this time.
Martin Lewis explained the logic behind this simple action: "When the sun is shining, it is letting light and heat into the house, so you want the curtains open. When it gets dark, it's not, so you want to keep the heat in by closing the curtains." This straightforward measure can help trap warmth inside during the colder evenings, potentially leading to lower heating requirements and reduced bills.
Context of Rising Energy Costs
This advice comes at a critical time for consumers. Energy bills rose by 2% for millions of households on standard variable tariffs in October 2025, following the latest Ofgem price cap increase. This change pushed the average annual dual fuel bill from £1,720 to £1,755, a hike driven by increases in electricity unit prices and standing charges.
The UK is also heading towards a cold snap, making effective and affordable heating a pressing concern for many families trying to manage their budgets.
Smart Technology Offers Future Hope
Alongside these immediate manual tips, a pioneering smart heat pump trial run by energy supplier OVO offers a glimpse into a more automated, efficient future for home heating.
The trial, which involved 58 households on OVO’s Heat Pump Plus tariff and was supported by the innovation foundation Nesta, explored whether smart automation could make heat pumps easier to manage while easing pressure on the national grid.
For three months, heating schedules were remotely adjusted. The system worked by preheating homes by 1°C during midday, when electricity is often cheapest and greenest, and then allowing them to cool by 1°C between 4pm and 7pm, when national demand typically surges and energy is more expensive and carbon-intensive.
The results were significant: electricity use during peak hours dropped by a third. This demonstrates a viable path to balancing grid demand and reducing energy costs, especially during the critical evening peak.
Chris Watling, Clean Heat Lead at OVO, said: "Heat pumps are a key part of cleaner, cheaper home heating, but they need to be affordable and simple for everyone to use. We're helping households move away from gas and switch to low-carbon heating that cuts bills, reduces carbon, and takes the strain off the grid."
He added that for this transition to be possible for every household, government support is needed to bring down upfront costs and ensure the right incentives are in place.
Together, Martin Lewis's practical tip and innovative trials like OVO's provide Britons with both immediate and long-term strategies to stay warm without facing exorbitant energy bills this winter.
