U.S. Boiler Company PV8H7, Installation, Operating And Service Instructions

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71
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 V8H 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. 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.
3. SUCTION LINE 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. Whatever it takes, The Oil Must Be Free
of Air . This can be a tough problem, but it must be
resolved. Try bleeding the pump through a clear
tube. There must be no froth visible. There are
various test kits available to enable you to look at
the oil through clear tubing adapted to the supply
line at the pump fitting. Air eliminators are on the
market that have potential. Also, electronic sight
glasses are being used with good success. At times,
new tubing must be run to the tank or new fittings
put on. Just make sure you get the air out before
you leave.
Any air leaks in the fuel line will cause an unstable
flame and may cause delayed ignition noises. Use
only flare fittings in the fuel lines.
4. 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.
5. 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.
SECTION XV: TROUBLESHOOTING
6. 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.
7. 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 locate the tank near the boiler in
the basement utility room or bury the tank and lines
deep enough to keep the oil above 40°F. Check
environmental issues with local authorities having
jurisdiction.
8. 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 target wall, the nozzle should be
replaced. If the condition persists look for fuel leaks,
air leaks, water or dirt in the fuel as described above.
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.
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.