Symptom: black smoke when burning.

Possible causes：
Maybe the damper is too small, or the position of the nozzle pen holder combination is too front.
It may be that the nozzle is not good or the oil pressure is insufficient, which affects the atomization of fuel and leads to poor combustion. The insufficient oil pressure may be due to the blockage in the oil supply system, in addition to the possible loss of sufficient oil pump or low oil pressure adjustment. Please check the oil filter and clean the oil tank.
Maybe the chimney is clogged, or there are bricks falling from the furnace, which hinders the combustion of the flame. If the burner is a furnace for alloy die casting machine, the alloy exuded from the pot containing alloy will accumulate in the furnace, which will hinder the flame, resulting in black smoke during combustion.
Too small furnace volume or chimney diameter may lead to black smoke during combustion. Perhaps the selected oil nozzle is too large. If the oil pressure is adjusted too high, the original furnace volume may change and cannot accommodate the increased flame, and black smoke will appear during combustion.
If the chimney is equipped with baffle, please pay attention to whether it is properly opened. If the chimney is equipped with exhaust fan, please pay attention to whether it is started.
It may be that the fan of the combustion engine has accumulated a lot of dirt and weakened the output combustion supporting air.