Method for buffering thermal energy in a thermal buffering medium contained within a thermal energy buffer having a controller and a heater, wherein at least one signal representing predetermined values related to the thermal energy buffer is provided to the controller, the predetermined values comprising: - a predetermined maximum temperature (T max) settable by a user, - a predetermined minimum temperature (T min), and - a predetermined minimum amount of thermal energy present in the thermal energy buffer settable by a user, wherein the controller calculates the following thermal values: - a value representing the amount of thermal energy present in the thermal energy buffer, - a minimal amount of heating energy representing an amount of energy required to, using the heater, heat all the thermal buffering medium to said predetermined minimum temperature starting from the amount of thermal energy present in the thermal energy buffer, and - a maximal amount of heating energy representing an amount of energy required to heat all the thermal buffering medium to said predetermined maximum temperature, using the heater, starting from the amount of thermal energy present in the thermal energy buffer, wherein the controller controls the heater of the thermal buffer in function of said thermal energy values such that the amount of energy present in the thermal energy buffer is higher than or equals the predetermined minimum energy present in the thermal energy buffer, wherein the volume of the thermal buffering medium is subdivided in one or more different parts such that the different parts of the volume of the thermal buffering medium together form the total thermal buffering medium present in the thermal energy buffer; and the thermal energy buffer comprises a respective temperature sensor for each different part for sensing a temperature of the thermal buffering medium contained in the part, characterised in that the controller calculates a value representing the amount of thermal energy present in the thermal energy buffer by multiplying the temperature measured by the one or more sensors sensing the temperature of the one or more different parts of the thermal buffering medium with the volume of the at least one part of thermal buffering medium such as to obtain at least one value representing the partial thermal energy contained in the at least one part by the thermal buffering medium and adding the resulting at least one partial thermal energy value to each other, wherein the controller calculates the minimal amount of heating energy by multiplying the difference between the predetermined minimum temperature and the temperature measured by the one or more temperature sensors of the one or more different parts containing thermal buffering medium having a temperature measured by their respective sensors, which is lower than the predetermined minimum temperature, with the respective volume of the different parts containing thermal buffering medium having a temperature measured by the respective sensors which is lower than the predetermined minimum temperature (T min), and adding the resulting values to each other, and wherein the controller calculates the maximal amount of heating energy by at least multiplying the difference of the predetermined maximum temperature and the temperature measured by the one or more temperature sensors with the respective volume of the part corresponding to the temperature sensor and adding the resulting values to each other. - a predetermined maximum temperature (T max) settable by a user, - a predetermined minimum temperature (T min), and - a predetermined minimum amount of thermal energy present in the thermal energy buffer settable by a user, - a value representing the amount of thermal energy present in the thermal energy buffer, - a minimal amount of heating energy representing an amount of energy required to, using the heater, heat all the thermal buffering medium to said predetermined minimum temperature starting from the amount of thermal energy present in the thermal energy buffer, and - a maximal amount of heating energy representing an amount of energy required to heat all the thermal buffering medium to said predetermined maximum temperature, using the heater, starting from the amount of thermal energy present in the thermal energy buffer,