Due to some problem in high pressure (HP) heaters in Shazand steam cycle power plant, sometimes these heaters should be eliminated from the cycle. At his condition, the main concern is keeping the constant value of power generation. The elimination of each heater changes the thermodynamic states in the numerous points of the cycle especially boiler and may put it in a destructive condition. The main goal of this paper is to find the maximum net power in elimination of HP heaters. For this purpose, total cycle is modeled and verified by the experimental data in which a lot of trial and error process has been done for each modeling of the whole cycle and the boiler outlets are required for many times in each cycle simulation. Then, ANN is used as an alternative and fast method for simulation of boiler and consequently the whole cycle. Different set of HP heaters have been eliminated from the cycle and new cycle condition is obtained. Afterwards, two boiler important parameters including metal and furnace exit gas temperatures have been checked at these new conditions. Finally, the cycle could provide 300 MW net power in elimination of HP heaters in each unit.