The procedure for deriving the parameters of drum type boilers dynamic model for long-term transient stability studies by use of heat balance data is presented in this paper. The main purpose of the work is to exhibit a regular procedure using available heat balance data of the steam plant boiler and thermodynamic properties of saturated steam and water, to be suitable for educational purposes. The parameters are shown to be in reasonable range. The model response to step changes with and without control loop is simulated and discussed as well. Furthermore, a practical scenario of the studied steam power plant is presented and the measured data are compared with simulation results.