Martin Lewis reveals simple thermostat trick to slash £90 off your energy bills

Struggling with rising energy bills? You’re not alone. With energy prices still well above pre-2020 levels, every penny saved counts—and Martin Lewis, founder of MoneySavingExpert.com, has shared a straightforward tip that could save you up to £90 a year. The best part? It takes just a few seconds.

The £90 Thermostat Trick

According to Martin Lewis, the easiest way to cut your heating bills is by reducing your thermostat setting by just one degree—for example, turning it down from 21°C to 20°C.

“It might sound like nothing,” he explained in a recent interview, “but if everyone in the UK did this, the national energy savings would be enormous. For a typical household, it’s about £90 a year just from that small tweak.”

And it’s not just about saving money. Lower energy use also means lower carbon emissions, so you’re helping the planet while easing pressure on your wallet.

How Does It Work?

Heating typically accounts for around 55–60% of the average UK household’s energy bills, according to the Energy Saving Trust. By lowering your thermostat:

Your boiler doesn’t have to work as hard.

It burns less gas or uses less electricity.

The system cycles on and off less frequently, extending its lifespan.

Over a 12-month period, even a 1°C reduction can add up to £90 in savings—and more in larger or less efficient homes.

Martin Lewis’s Top Energy-Saving Tips

Martin Lewis recommends combining the thermostat tip with a few other energy-saving habits for even bigger results:

Turn off standby appliances – TVs, game consoles, and microwaves left on standby still draw power. Switching them off at the plug can save up to £45 per year.

Lower your boiler’s flow temperature – Set it to 60°C (if you have a combi boiler). Many boilers are set too high by default, and this one change could improve efficiency by 6–8%.

Use heating only when needed – Don’t waste energy heating empty rooms or running the heating when you’re not home. Use radiator thermostats and timers to stay in control.

Expert Insight: MAC Renewables Weigh In

MAC Renewables, experts in home energy solutions and renewable technologies, support the advice—and say it’s just the start of what’s possible.

“People often underestimate how effective small changes can be,” says a spokesperson from MAC Renewables. “Lowering your thermostat by just one degree not only saves money—it also reduces your carbon footprint. When combined with smarter heating habits and proper insulation, it can have a big impact.”

The team at MAC Renewables also highlight the longer-term benefits of switching to low-carbon systems, such as air source heat pumps or solar panels, especially now that government grants are available through schemes like the Boiler Upgrade Scheme.

“Short-term savings are vital right now—but the real win is future-proofing your home with cleaner, more efficient heating systems.”

Small Change, Big Results

With the cost of living still high and energy tariffs unpredictable, small changes can make a meaningful difference. Martin Lewis’s advice proves you don’t need to overhaul your home to cut costs—sometimes, all it takes is turning a dial.

So if your thermostat is set to 21°C or above, try nudging it down by a degree. You likely won’t notice the temperature difference—but your bank account will.