Abstract: In view of low water temperature in power plant No.1 and No.2 high pressure heater outlet through the analysis of the inspection, confirm the reason was that high pressure heater water chamber clapboard in bolt and nut off, most of the diaphragm seal were missing, resulting in high pressure water chamber heater circuit, export water temperature decrease. After getting rid of the high-pressure heater clapboard gasket, replacing the bolt, the export water temperature rised with 6.38℃, thus reduce the unit power generation coal consumption about 0.72 g/kWh, and the energy saving effect was obvious.