Martin Lewis' Money Saving Expert (MSE) has weighed in on whether it is better to leave your heating on all day or switch it off when not needed, concluding that "leaving the heating on all day leads to greater heat loss and means higher cost" — but noting the best approach depends on individual circumstances.
The verdict draws on expertise from the Energy Saving Trust, British Gas, an independent plumber and MoneySavers social media. The debate resurfaces as the heating season gets under way, with energy bills having risen by £60 a year from October after Ofgem increased the energy price cap by 4%.
Energy price cap rise
The energy price cap increased to £1,723 a year for the typical household for people who are not on a fixed tariff and pay by Direct Debit in England, Scotland and Wales, up from the £1,663 cap currently in place. That works out as an extra £5 a month for the average household.
The Energy Saving Trust maintains that keeping the heating running all day is the less efficient option. It recommends heating your home only when required, meaning you pay solely for what you actually use. Fitting a timed thermostat is considered the most effective way to maintain your preferred temperature at the times that suit you best.
When low and slow may win
However, if you own a modern boiler or heat pump, work from home, or spend the majority of your evenings and weekends indoors, Heat Geek argues that the low and slow method comes out on top. Heat pumps are a low-carbon form of electric heating that extract warmth from the outside air, while a modern condensing boiler installed after 2005 recovers some waste heat before it escapes.
In such circumstances, maintaining a steady indoor temperature of 18 or 19°C could prove more efficient. Keeping temperatures low with gradual heating responsiveness — avoiding cranking up the thermostat when you feel cold — allows the boiler to recover more waste heat. Low and slow also prevents condensation building up within the walls each time the heating is switched off, which can draw heat out of your home while encouraging damp and mould.
Trial and error approach
That said, this approach may not suit you if you are frequently away from home or have plasterboard walls, which tend to warm up more quickly. However, if your property benefits from cavity wall and loft insulation or underfloor heating, low and slow is the recommended option.
As no definitive answer exists, MSE suggests a trial and error approach — comparing energy consumption with each method. Take meter readings at the beginning and end of each trial period and compare the results, ensuring you match the temperatures of the weeks being tested as closely as possible.
