nozzle will compress when burner is on and will expand when burner stops, causing oil to squirt from nozzle at low pressure as burner slows down and causing nozzle to drip after burner stops. Usually cycling the burner operation about 5 to 10 times will rid oil line of this air.
2.IF NOZZLE CONTINUES TO DRIP, repeat step N.1. If this does not stop the dripping, remove cut off valve and seat, and wipe both with a clean cloth until clean. Then replace and readjust oil pressure. If dripping or after burn persist replace fuel pump.
O.HINTS ON 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 RSA 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 CO2 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 carry.
2.FLAME SHAPE — Looking into the combustion chamber through the flame plug hole, the flame should appear straight with no sparklers rolling up toward the top of the chamber. If the flame drags to the right or left, sends sparklers upward or makes wet spots on the combustion chamber, the nozzle should be replaced. If the condition persists look for fuel leaks, air leaks, water or dirt in the fuel as described below.
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.
There may be many possible causes of leaks in oil lines such as:
a.Fitting leaks due to misflared tubing or damaged fitting.
b.Fuel line leak due to crushed or bent tubing.
c.Filter connection leaks.
d.Tank connection leaks.
The following actions can eliminate air leaks:
a.Bleed pump as detailed in System
b.Replace flare fittings.
c.Replace oil supply line.
d.Repair oil filter leaks
e.Replace or repair tank fittings.
5.GASKET LEAKS— If 11.5% to 12.5% CO2 with a #1 smoke cannot be obtained in stack, look for air leaks around the canopy seal. Such air leaks will cause a lower CO2 reading in the stack. The smaller the firing rate the greater effect an air leak can have on CO2 readings.
6.DIRT— A fuel filter is a good investment.
Accidental accumulation of dirt in the fuel system can clog the nozzle strainer and produce a poor spray pattern from the nozzle.
7.WATER— Water in the fuel, in large amounts, will stall the fuel pump. Water in the fuel pump, in smaller amounts, will cause excessive wear on the pump, but more importantly water does not burn.
It chills the flame, causes smoke, and allows un- burned fuel to pass through the combustion chamber and clog the flueways of the boiler.
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.
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 buried in the ground above the frost line is a good candidate for cold oil. The best solution is to place the tank and oil lines in the ground below the frost line.
9.HIGH ALTITUDE INSTALLATIONS
Typically, the rule to use for high altitudes is to increase the air supply by 4% per each 1000 ft. above 2000 ft. altitude from sea level. This means that the air setting will have to be higher than the calibration marks in proportion to the altitude. Use instruments and set for 11.5 to 12.5% CO2.
10.
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
35
