Should You Leave Your Heating On Constantly or Use It Intermittently?
As colder months settle in across the UK, many households face the age-old dilemma: is it better to leave the heating on all day at a low level, or switch it on and off as needed? With energy bills still high and winter looming, understanding the science and economics behind each method is crucial.
The Case for Intermittent Heating
The idea that it’s cheaper to leave your heating on low all day is a myth. Heating your home only when necessary—using a timer and thermostat—is the most efficient approach for most properties.
Why it works:
• Less energy waste: You’re not constantly pumping heat into an empty or already-warm space.
• Lower heat loss: Homes lose heat over time, especially if poorly insulated. Continuous heating increases this loss.
• Smart thermostats help: Devices like Hive or Nest optimise heating schedules based on your habits and weather conditions.
When Constant Heating Might Help
There are exceptions. In older or poorly insulated homes, keeping the heating on low may reduce condensation, which can otherwise collect in walls and increase heat loss when the system is turned off.
Pros:
• May prevent damp and mould in vulnerable buildings.
• Avoids sudden spikes in energy use when reheating cold spaces.
Cons:
• Higher overall energy consumption.
• Less efficient for modern boilers and well-insulated homes.
System Type Matters
• Traditional boilers: Work best with intermittent heating, especially modern condensing models that are more efficient at lower flow temperatures.
• Heat pumps: Often more efficient when maintaining a steady temperature, especially in well-insulated homes.
Energy-Saving Tips for Any Setup
• Use TRVs (thermostatic radiator valves) to control heat room-by-room.
• Close off unused rooms to prevent unnecessary heating.
• Open curtains during sunny hours, but close them at night to retain warmth.
• Seal draughts around windows, doors, and floorboards.
• Layer up: Sometimes heating the person is more cost-effective than heating the space.
Final Thoughts
For most UK homes, intermittent heating with a timer and thermostat is the best approach—especially when paired with good insulation and smart controls. However, if your property is prone to damp or has poor thermal retention, a low, steady heat may offer comfort and protection.
