The fuel oil supply system to an automatic auxiliary boiler, will automatically shutdown if the boiler （）

A.incorrect electrode setting
B.incorrect nozzle position
C.clogged fuel nozzle
D.broken high tension lead

A.relight the boiler immediately to prevent loss of steam pressure
B.relight the fire off the brickwork as the bricks are cherry red
C.purge the furnace of any combustible gases before attempting to relight the fire
D.speed up the feed pump to prevent dry firing when the burner flame is reestablished

A.in the event of a flame failure
B.in the event of a stack fire
C.when the water level reach the crown sheet
D.when the feed pump discharge pressure drops to a preset minimum