In this paper we present the innovative procedure to compare different activation methods by thermal analysis. For obtaining geopolymeric/zeolitic materials from power plant, ash is used different methods: direct activation, fusion, ultrasound and microwave. In this study, we present the samples synthesised in conditions: 20 °C time 168 h, direct activation at 70, 90 and 150 °C, for 4, 8 and 12 h and ultrasound method –70 °C, 1 h respectively 2 hours. After activation the samples were cooled and crystallization at 20 °C for 18 h. After this all samples were filtered, washed at pH 8, with distilled water, and dried at 80 °C for 4 h. We selected these conditions for economic reasons. Fly ash and activated materials were characterised by SEM/EDAX, XRD, BET, FT-IR, thermal analysis. According to the experimental results the synthesised materials have a BET surface between 21-122 m2/g, bigger than ash 7 m2/g. The FT-IR and XRD analysis demonstrated that the ash contains: quartz, kaolinite, muscovite, mullite, and vitreous phase. In activated materials were found mixtures of geopolymers/zeolites phases: quartz, analcime, sodalite, chabazite, faujasite, Na-Y, tobermorite, etc. According to the loss on ignition (LOI) and the DTG for ash, was observed that the weight loss is a three-stage process: water evaporation, coal combustion and loss of water of crystallization, total LOI was 6.52 %. The values of the LOI are higher for the activated materials comparatively with ash. Comparing different methods, the LOI values are higher for direct activation samples than samples obtained by ultrasonic method. It is because the zeolite synthesis is more efficient in direct activation case (higher level of hydration - fact demonstrated by adsorption capacities). The materials obtained by ultrasound method have only two stages of LOI and total loss are closed of value of ash. In the case of materials synthesized by direct activation was observed four stages of loss on ignition, and total LOI increase at 23.84 %, function of activation conditions. The use of DTG/DTA curves permit to determine the amount and nature of chemical species lost during the heating process. The endothermic and exothermic peaks, offer information regarding: the dehydration, amorphization/recrystallization process. All DTA curves confirmation a distinct endothermic peak in the range of 30–475 °C due to desorption of zeolitic water, and small exothermic peaks at higher temperatures due to zeolite destruction and crystallization of new phases. The temperature of the first exothermic peak represents measure of the thermal stability. Thermal analysis permits identification of the materials and allowed elucidation of the processes occurs during the thermal heating, for establishing the better activation method.