How do smart heating algorithms work? | Legrand België

The algorithm is your connected thermostat's 'brain' and allows it to make decisions and fire up the boiler based on: heating history, room temperature, setpoint temperature and the chosen heating algorithm.

You can switch between the Hysteresis and PID advanced algorithm in the app settings: Settings > My Home > Room of your thermostat > My thermostat > Advanced settings.

Hysteresis algorithm

With this algorithm, when the difference between the setpoint and room temperatures is within a given sensitivity threshold, the thermostat assumes the setpoint temperature has been reached.

You can adjust the Hysteresis algorithm sensitivity threshold in the thermostat's advanced settings. If you use smaller thresholds (0.1 °C), the thermostat will be more responsive to room and setpoint temperature changes. With larger thresholds, the thermostat will be more tolerant to variations in these temperatures and will switch the heating on and off less often.

NB: This algorithm is recommended for wood-burning stoves.

Advanced algorithm (PID)

The Proportional-Integral-Derivative (PID) heating algorithm is more intelligent than the Hysteresis algorithm, enabling improved temperature regulation with fewer oscillations around the setpoint temperature. It takes the specific characteristics of your home into account (thermal inertia, insulation, etc.).

When you first install the thermostat, only the Hysteresis mode is available.

Over the first few weeks of heating, the thermostat will determine the specific characteristics of your home, including its thermal inertia and insulation.

The PID cannot be activated until the thermostat has completed this initial configuration.

It can then be deactivated to switch back to Hysteresis mode.

Comments

• Settings can only be configured during cold periods, when the Thermostat is actively controlling the heating.

• When the temperature in the home rises quickly, you are advised to use setpoint temperatures with several degrees' difference between Comfort mode and Eco mode to give the thermostat clear benchmarks.

Specific issues

• The advanced heating algorithm (PID) is only useful for systems with high inertia, and is therefore not recommended in cases where the standard Hysteresis algorithm is already producing excellent results (heated floors, etc.).

• The advanced heating algorithm is not recommended for devices that require significant fire-up and shut-down times since this can adversely affect their good working order and lifespan (examples include pellet-fired stoves and some heat pumps).

• The PID is automatically deactivated for all setpoint temperatures up to 14°C; there is no point in using the heating more often to turn it on or off when nobody is home.

• For Netatmo Smart Radiator Valves, the system will automatically switch to PID mode once configuration is complete. Neither of the algorithms can be force-activated.