U.S. Boiler Company MegaSteam MST288, Installation, Operating And Service Instructions

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103536-08 - 4/18
A. COMBUSTION
1. NOZZLES — Although the nozzle is a
relatively inexpensive device, its function is
critical to the successful operation of the oil
burner. The selection of the nozzle supplied
with the MegaSteam™ boiler is the result of
extensive testing to obtain the best flame
shape and efficient combustion. Other brands
of the same spray angle and spray pattern
may be used but may not perform at the
expected level of CO
2
and smoke. Nozzles are
delicate and should be protected from dirt and
abuse. Nozzles are mass-produced and can
vary from sample to sample. For all of those
reasons a spare nozzle is a desirable item for a
serviceman to have.
2. FLAME SHAPE — Looking into the
combustion chamber through the observation
port, the flame should appear straight with no
sparklers rolling up toward the crown of the
chamber. If the flame drags to the right or left,
sends sparklers upward or makes wet spots
on the chamber walls, the nozzle should be
replaced. If the condition persists look for
fuel leaks, air leaks, water or dirt in the fuel as
described above.
3. FUEL LEAKS — Any fuel leak between the
pump and the nozzle will be detrimental to
good combustion results. Look for wet surfaces
in the air tube, under the ignitor, and around
the air inlet. Any such leaks should be repaired
as they may cause erratic burning of the fuel
and in the extreme case may become a fire
hazard.
4. AIR LEAKS — Any such leaks should be
repaired, as they may cause erratic burning of
the fuel and in extreme cases may become a
fire hazard.
5. GASKET LEAKS — If 11.5 to 12.5% CO
2
with a #1 smoke cannot be obtained in the
breeching, look for air leaks around the
burner mounting gasket, observation door,
and canopy gasket. Such air leaks will cause
a lower CO
2
reading in the breeching. The
smaller the firing rate the greater effect an air
leak can have on CO
2
readings.
6. DIRT — A fuel filter is a good investment.
Accidental accumulation of dirt in the fuel
system can clog the nozzle or nozzle strainer
and produce a poor spray pattern from the
nozzle. The smaller the firing rate, the smaller
the slots become in the nozzle and the more
prone to plugging it becomes with the same
amount of dirt.
7. WATER — Water in the fuel in large amounts
will stall the fuel pump. Water in the fuel in
smaller amounts will cause excessive wear on
the pump, but more importantly water doesn’t
burn. It chills the flame and causes smoke and
unburned fuel to pass out of the combustion
chamber and clog the flueways of the boiler.
8. COLD OIL — If the oil temperature
approaching the fuel pump is 40°F or lower,
poor combustion or delayed ignition may
result. Cold oil is harder to atomize at the
nozzle. Thus, the spray droplets get larger and
the flame shape gets longer. An outside fuel
tank that is above grade or has fuel lines in a
shallow bury is a good candidate for cold oil.
The best solution is to bury the tank and lines
deep enough to keep the oil above 40°F.
9. HIGH ALTITUDE INSTALLATIONS —
Air openings must be increased at higher
altitudes. Use instruments and set for 11.5 to
12.5% CO
2
.
10. START-UP NOISE — Late ignition is the
cause of start-up noises. If it occurs recheck for
electrode settings, flame shape, air or water in
the fuel lines.
11. SHUT DOWN NOISE — If the flame runs
out of air before it runs out of fuel, an after burn
with noise may occur. That may be the result
of a faulty cut-off valve in the fuel pump, or it
may be air trapped in the nozzle line. It may
take several firing cycles for that air to be fully
vented through the nozzle. Water in the fuel or
poor flame shape can also cause shut down
noises.
B. OIL PRIMARY CONTROL
1. Burner (control) will not come on.
a. No power to control.
b. Control is in lockout or restricted mode.
Press reset button for one (1) second to exit
lockout. If control has recycled three times
within the same call for heat, it will enter into
restricted mode. To reset from restricted
mode, refer to Section VIII, Paragraph I, No.
2 for details.
NOTICE CHECK TEST PROCEDURE. A very
good test for isolating fuel side problems is
to disconnect the fuel system and with a 24"
length of tubing, fire out of an auxiliary five
gallon pail of clean, fresh, warm #2 oil from
another source. If the burner runs successfully
when drawing out of the auxiliary pail then
the problem is isolated to the fuel or fuel lines
being used on the jobsite.
Section XI: Trouble Shooting