As temperatures drop, the perennial debate over the most economical way to heat our homes has reignited. Should you leave your heating on a constant low setting all day, or only fire it up when you need warmth? Martin Lewis's Money Saving Expert (MSE) team has now delivered a comprehensive verdict, drawing on expert advice to settle the argument.
The Great Heating Debate: 'Low and Slow' vs 'On Demand'
The 'low and slow' method suggests that maintaining a steady, low temperature throughout the day is more effective and could be cheaper. However, the opposing view, championed by bodies like the Energy Saving Trust, argues that this leads to unnecessary heat loss and higher bills. After consulting sources including British Gas, independent heating engineers, and its own community, MSE has provided what it calls the most thoroughly researched guidance available.
The core conclusion from the investigation is clear: "leaving the heating on all day generally leads to greater heat loss and means higher cost." The Energy Saving Trust firmly states that keeping your heating running around the clock is less economical. The recommended strategy is to heat your home precisely when you need it, ensuring you only pay for energy when it's essential.
When Does 'Low and Slow' Actually Work?
Despite the general rule, the report acknowledges there is no one-size-fits-all answer. The efficiency of your heating system and your home's insulation are critical factors. For instance, advice from Heat Geek indicates that if you have a modern condensing boiler (installed post-2005) or a heat pump, and you are at home most of the day, the 'low and slow' approach could be more efficient.
This is because modern systems can recover waste heat more effectively when operating at a constant, low temperature. Maintaining a steady 18 or 19°C and avoiding sudden high demands allows the boiler to work optimally. This method can also be ideal for homes with good cavity wall and loft insulation or underfloor heating.
An additional benefit cited for 'low and slow' is that it may prevent condensation from forming inside walls when the heating is switched off, which can lead to damp and mould issues.
How to Find Your Home's Best Heating Strategy
Given the variables at play, MSE ultimately recommends a trial and error approach for homeowners. The best way to determine what saves you money is to conduct your own experiment.
Try one method for a week, taking meter readings at the start and end. Then, try the other method for a week under similar weather conditions, again noting your meter readings. Comparing the energy usage from both weeks will give you a personalised answer for your specific property and lifestyle.
For most, using a programmable thermostat to heat the home only when required remains the most cost-effective and energy-saving strategy. However, if your home is very well-insulated and you have a modern heating system, a constant low temperature might work for you.
