Known to be the most important item of expenditure for a household ( 66% of the energy consumption of a home according to ADEME figures ), heating must be optimized at the risk of seeing the energy bill s fly away.

At first glance, it would seem wise to turn off the heating when you are away in order to limit its use as much as possible. What is it in reality?

A false good idea

Turning off your heating during a one-time absence (work, weekend, etc.) is not a good thing. Indeed, the radiators tend to overheat at the time of re-ignition to compensate for the time lost. They will then generate significant energy which will weigh on the energy bill. In the event of prolonged absence, you must turn off your heating.

The Environment and Energy Management Agency (ADEME) recommends turning down the heating when you are away during the day, rather than turning it off completely . Among the options available to reduce energy bills, she recommends adopting dynamic temperature management according to the hours of presence.

In her guide , she advises setting “the temperature between 19 and 21°C in occupied rooms during the day, and at 17°C at night and during the day in unoccupied rooms”. She suggests using thermostatic valves and timers to regulate the heat emitted by radiators.

Another alternative available: use a smart thermostat like that of the French Netatmo (provided that it is compatible with your boiler).

Beware of thermal colanders

However, this observation is not valid in the case of a thermal sieve with poor insulation. It is for this reason that ADEME recommends “above all, insulate your home”. In France, 7 million homes are poorly insulated and consume a lot (too much) energy for heating.

If you are in such a situation, you can contact the advisers of the Espaces Info Énergie to find out about the techniques and financial aid available. Once you have carried out your energy balance, you will be able to know the most economical solution to choose.

Energy losses on a non-insulated dwelling © ADEME

Indeed, a well-insulated home retains heat better. It uses less energy for heating and allows you to reduce your bill at the end of the month. If you are in a thermal strainer, it will be better to cut the heating to the maximum so as not to heat up unnecessarily when you are away.

In any case, before planning the renovation of the heating system, it is essential to improve the insulation of your home. If you start by renovating your heating in a poorly insulated home, you will need powerful (and therefore more expensive) equipment for heating. Counter productive.