n short: Not usually. But it depends.
✅ When it might save money:
- You have an old, inefficient boiler.
- Your home holds heat well (good insulation).
- You’re on a timer and only need heating in short bursts.
❌ When it doesn’t help (and could cost more):
- Condensing boilers (modern ones) are more efficient when left on low overnight.
- Reheating a cold house in the morning can use more energy.
💡 Better option:
- Set the thermostat lower at night (e.g., 16–17°C).
- Use smart thermostats or programmable timers.
- Heat only occupied rooms.
📉 Bottom line: Turning your boiler completely off overnight may save a little, but it’s often better to turn it down and use a schedule