Burnham MST629, MST288, MST396, MST513 manual Section XI Trouble Shooting

SECTION XI: TROUBLE SHOOTING

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 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 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% CO2 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 CO2 reading in the breeching. 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 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

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% CO2.

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.

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.
c.	CAD cell seeing light.
d.	CAD assembly defective.
e.	Control motor relay is stuck closed (see note
	below).
2. Burner (control) will light, then shut down after a
short time, then restart after one (1) minute.
a.	CAD cell is defective.
b.	Air leaking into oil line causing flame out.
c.	Defective nozzle causing flame to be erratic.

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flueways of the boiler.