Heating at night: should it be switched off or simply turned down?

Lowering the temperature by 3°C at night can save up to 20% on nighttime heating costs.
Over a full season, this represents several tens, or even hundreds, of euros depending on the property.
The right temperature for each room:
Experts recommend:

Bedrooms: 16–17°C
Living room in the evening: 19–20°C
Bathroom (when in use): 21–22°C
Hallways / rooms rarely used: 15–16°C
The crucial role of the thermostat
A programmable thermostat is now the most effective weapon against waste: Bathroom furniture

It automatically lowers the temperature at night.
It restarts the heating just before waking up.
It prevents forgetfulness and excesses.
Result: more comfort, less stress, and a reduced bill without thinking about it.

In what situations can you really turn everything off?
There are a few exceptions where turning it off might be considered:

Very recent and perfectly insulated housing.
Absence of several days.
Region with a very mild climate.
But in the majority of conventional housing, lowering the temperature remains more profitable than cutting it.

Good habits to adopt at night
to maximize savings:

Close shutters and curtains completely.
Avoid turning the heating up too high in the morning.
Ventilate briefly (5 to 10 minutes), even in winter.
Never block radiators.