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Figure 18: Electrode / Head Setting
7.Bleed the fuel unit when the burner motor starts rotating. To bleed, loosen the vent fitting (with plastic hose attached) and catch the oil in an empty container. Continue to bleed for 15 seconds after oil is free of air bubbles. Tighten the vent fitting when all the air is purged. NOTE: Bleeding might not be necessary with a two pipe system. When vent fitting is closed, burner flame should start immediately.
8.ADJUST OIL PRESSURE
a.Locate oil pressure adjusting screw and turn screw to obtain 140 PSIG pressure.
b.DO NOT REMOVE PRESSURE GAUGE until later.
9.ADJUST AIR SETTING on burner for a light orange colored flame. Use a smoke tester and adjust air for minimum smoke (not to exceed #1) with a minimum of excess air. Make final check using suitable instrumentation to obtain a
CO2 of 11.5 to 12.5%. These settings will assure a safe and efficient operating condition. If the flame
appears stringy instead of a solid fire, try another nozzle of the same type. Flame should be solid and compact.
10.TURN "OFF" BURNER BY OPENING SERVICE SWITCH. Remove pressure gauge. Install gauge port plug and tighten.
11.HINTS ON COMBUSTION
a.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 microTEKDV 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
b.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 rear door insulation piece, the nozzle should be replaced. If the condition persists look for fuel leaks, air leaks, water or dirt in the fuel as described below.
c.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 transformer, 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.
d.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 are many possible causes of air leaks in oil lines such as:
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