1. Check the pressure gauge in the control room and the local pressure gauge to determine whether the pressure is really rising. 

2. When the pressure of the deaerator rises, check whether the load of the unit rises or not, so that No.2 extractor pressure rises; or whether the thermal load is shed by outside grid, causing steam heating pressure to rise, and the pressure of the deaerator rises. 

3. If the electric regulating valve of steam-admission is in failure, the manual regulating valve can be used for regulating. 

4. Check whether the valves of demineralized water system, relay water system or the condensate water system are closed by mistake or the valves spools fall off, causing the water level of the dearator to be too low. If it is too low, the make-up water valve shall be opened wide. 

5. If the load of the unit is too high and the extraction steam pressure rise, it is possible to adjust the load or turn down the steam-admission valve to maintain normal pressure. 

6. If other steam source enters, the causes shall be immediately found out and the related steam-admission shall be cut off. 

7. When the measures taken above mentioned are invalid, the load of the unit shall be immediately reduced.