A hollow cone nozzle generally gives greater freedom from
pulsation than a solid cone nozzle.
A wider spray angle sometimes helps a pulsating
condition. It may even be necessary to use a 90° nozzle. In this case watch
for smoke at the outer edges of the fire.
Reduce the firing rate to the next smaller nozzle if it
will carry the heating load.
The combustion chamber may be too large, allowing the
fire to leave the burner.
Higher oil pressure sometimes helps because it gives a
more stable spray pattern and smaller droplets, which burn closer to the
Be sure there is air intake into the boiler room.
Sometimes a flame retention burner will cure or improve a
pulsating or rumbling condition.