Heating bills drop more from sealing leaks than from turning the thermostat down. Here is the order to tackle things in.
A large share of heating goes into warm air escaping through window gaps and the front door. Before lowering the thermostat by a degree, check weather strips, insulating film and curtains. Old window frames leak the most, and a single strip makes a noticeable difference. Closing curtains at night alone cuts heat loss through glass considerably.
Turning the boiler fully off while you are out lets the home cool, and reheating it costs more than holding a lower temperature. For a few hours away, 'away' mode or a setting 2โ3 degrees below normal is cheaper. Switching off only makes sense for a day or more.
The same 20ยฐC feels colder when the air is dry. A humidifier or a damp towel bringing humidity to 40โ50% lets you drop the setting by a degree or two with the same comfort โ far cheaper than heating more.
Closing valves and doors in unused rooms shrinks the area you actually heat. Fully closed rooms grow condensation and mould, so air them occasionally. Under-floor heating is trapped by thick rugs, so keep coverings thin where you sit most.
Each button runs this keyword on that search engine