Overview
- Reports advise keeping rooms at roughly 16–18 °C overnight through a night setback to curb energy use and reduce mold risk.
- A rule of thumb from consumer advisers says turning the heat down pays off after about four hours away from home.
- Whether a setback saves money depends on duration and depth of the reduction, heating technology, outdoor temperatures, and a building’s thermal inertia.
- Well‑insulated homes with heat pumps and underfloor heating may see little benefit or even higher costs from deep night setbacks, while leaky buildings can benefit more.
- Consumers can test their setup on a 0 °C night by comparing evening and morning indoor temperatures (about a 3 °C drop suggests savings), keep rooms above 16 °C with regular airing, use thermostats or smart controls, and apply simple power tips like switching off lights after three minutes, unplugging devices, and timing hot‑water boilers.