Turning the heat off is usually more economical than leaving it on, even for a very short absence. “Even if you’re going out for five minutes to buy bread, it pays off to switch it off,” a heating specialist told our newsroom.
Consumer protection organizations say that switching off heating at night can save up to 67 percent. Other studies estimate that turning the heat down or off while you are away, even for short or moderate periods, can cut annual bills by 8 to 15 percent.
The logic is simple: when the system runs, it continuously uses energy to replace heat lost through walls, ceilings, and windows. If no one is home, you are paying to maintain a temperature nobody is using.
Debunking the cost-of-restart myth
The belief that firing up the boiler costs more than keeping it running needs to go. It is true that when you restart the system it will work harder briefly to restore the temperature, but that short spike is usually lower than the steady consumption required to keep the house heated while it’s empty.
Preventing heat loss is closely related to this point. Use the common measures recommended by the International Energy Agency: seal gaps with weatherstripping tape, exploit daytime solar gain with blinds or curtains and close them at night, ventilate briefly without cooling down walls, and configure your system to operate in its efficient range.
If possible, use programming or a smart thermostat so you heat only when people are home, not while the house sits empty.
Thermostat settings and system differences
Don’t overdo the degrees. Generally, a comfortable daytime indoor range is about 19 to 21 degrees Celsius, and you can drop the temperature a lot at night or even switch the heat off depending on the situation.
Each degree above that range increases the bill by roughly 7 percent, so it’s better to set the thermostat sensibly than try to chase a higher temperature with extra heat later.
Not all heating systems react the same way. Underfloor heating has high thermal inertia and does not respond well to very short shutdowns because it can take hours to warm up or cool down. For those systems, a steadier, well-programmed control strategy is usually preferable.
Additional tips to optimize heating use
Regular maintenance of heating systems is essential. A well-maintained system runs more efficiently and lasts longer, producing meaningful long-term savings.
Proper home insulation reduces heat loss and keeps rooms warm longer. That includes insulating walls, ceilings, and floors and installing double-glazed windows.
Thermal curtains can also cut heat loss through windows by blocking outside cold and retaining indoor warmth.
Finally, consider renewable heating options such as geothermal heat pumps or solar thermal panels. Although upfront costs can be high, they may deliver substantial energy bill reductions over the long term.
