Manifestation 1: the water level of the coal-fired water heater is below the minimum safe water level, and the water level gauge glass tube is white.
Manifestation two: the water level alarm sends out alarm signal.
Form three: the blower, the induced blower and the motor of the grate reducer stopped running.
Manifestation 4: the superheater steam temperature rises sharply, and is higher than the normal outlet steam temperature.
Manifestation 5: the temperature of boiler exhaust rises, and the rise of coal-fired water heater is abnormal.
Six: severe water shortage, the furnace tube may appear broken.