As winter tightens its grip and energy bills remain a pressing concern, millions of households across the UK are facing a familiar and costly question: is it cheaper to leave the heating on all day or to turn it on only when needed? The answer, according to an exhaustive investigation by Martin Lewis's Money Saving Expert, is not a simple one and depends heavily on your specific circumstances.
The Great British Heating Debate
The common belief that keeping your radiators on a constant low setting throughout the day is the most economical method is being challenged. Money Saving Expert (MSE) has delved into the issue, consulting research from the Energy Saving Trust, British Gas, an independent plumber, and feedback from its own community of 'MoneySavers'.
The prevailing expert view, as reported by MSE, indicates that "leaving the heating on all day leads to greater heat loss and means higher cost." The Energy Saving Trust firmly advocates for heating your home only during the periods you actually need it, thereby ensuring you are not paying to warm an empty house.
When 'Low and Slow' Wins the Day
However, the picture is not entirely one-sided. For some households, the 'low and slow' method—maintaining a constant temperature—can be more efficient. This approach is particularly advantageous if your home meets certain criteria.
According to heating specialists Heat Geek, this method is best for homes with:
- A modern condensing boiler (installed after 2005) or a heat pump.
- Good insulation, such as cavity wall and loft insulation or underfloor heating.
- Occupants who are at home all day or most evenings and weekends.
The science behind this is that modern systems can recover more waste heat when operating at a steady, low temperature, such as 18 or 19°C. Furthermore, maintaining a constant temperature can help prevent condensation from forming inside walls when the heating switches off, which can lead to damp, mould, and actually conduct heat away from your home.
Finding Your Personal Heating Strategy
For those with older heating systems, plasterboard walls that heat up quickly, or who are out of the house for long periods, the advice is clear: turning the heating on and off as required is almost certainly the cheaper option. The most effective way to manage this is by using a programmable thermostat to ensure your home is warm only when you need it to be.
With no single answer applying to everyone, MSE recommends a practical approach of trial and error. To find out what works best for your home, you can conduct your own experiment.
Take a meter reading at the start of a week and use one method, ensuring you note the outdoor temperatures. The following week, try the other method under similar weather conditions. Take another meter reading at the end of the second week and compare the energy usage. This hands-on test will provide you with a definitive, personalised answer to the great heating debate.
