The hysteresis threshold is an advanced setting that allows you to adjust the sensitivity of your thermostat. It defines the temperature difference tolerated before your heating turns on or off.
How Does This Setting Work?
This setting is expressed in degrees (e.g., 0.5°C, 1°C, 2°C). It directly influences the behavior of your heating system:
- Low threshold (e.g., 0.5°C): The thermostat is very responsive. It maintains a very stable temperature, close to the setpoint, but this causes your boiler or radiators to turn on and off very frequently.
- High threshold (e.g., 2.0°C): The thermostat is more tolerant. The temperature will vary more around the setpoint, but heating cycles will be longer and less frequent.
What Are the Risks?
⚠️ Why should you not set a value too low (below 0.5°C)?
Even if your thermostat allows setting a very low threshold (like 0.1°C or 0.2°C), we strongly advise against going below 0.5°C.
Seeking extreme precision causes "short cycling" (the heating turns on and off every few minutes). This leads to:
Premature wear of the system
Overconsumption: The startup phases consume the most energy.
How to Find the Right Balance?
The ideal setting depends on the thermal inertia of your heating system:
Electric radiators or standard water radiators (Steel/Aluminum): A value of 0.5°C is recommended. This is the best compromise between comfort and energy savings for most homes.
Cast iron radiators (High inertia): A value between 0.5°C and 1.0°C helps prevent the radiators from cooling down too much between heating cycles while limiting startups.
Underfloor heating or Pellet stove (Very high inertia): A value of 1.0°C or higher is generally preferable to limit system wear. Note: On underfloor heating, a high threshold protects the boiler but may cause slight temperature variations (warm/cool sensations) due to the floor's reaction time.