1. The water level rises and exceeds the waterline seen at upper part of the   water level gauge, the glass tube water level gauge is in dark. 

2.The water level gauge alarms for high water level. 

3. The superheated steam temperature drops and the salinity in steam salinity increases.

4. The water supply flow is abnormal and is larger than the steam flow. 

5. In serious condition of full water, the steam pipe water impacts and white steam emits from the flange.