The dynamic heat capacity of heptacosane was measured by ac calorimetry. Samples with a homologous purity of 99.9% were used. The characteristic feature of ac calorimetry of excluding latent heat made it possible to study details of the dynamic heat capacity of the rotator phase. In both the heating and cooling processes at a constant rate of 0.5 K/min, slow motion with a correlation time comparable to 1/3 s was observed. At constant temperatures of the rotator phase significant and slow annealing effects were observed. Experimental results showed that the equilibrium state at temperatures equal to or higher than 329.9 K was apparently different from the equilibrium state at temperatures equal to or lower than 329.5 K. It was shown that the observed experimental results could be explained by assuming existence of a parameter which changes only very slowly.