Dunkirk Excelsior EXB Series Supplemental Instructions page 18

Beckett NX: System and General Troubleshooting
Problem
Oil burner sputtering at nozzle
Excessive fuel oil consumption.
Too much smoke.
Soot building up on blast tube (end
coning).
Boiler will not warm home to desired
temperature.
Home does not heat evenly
OPERATION AND TROUBLESHOOTING
Possible Cause
Electrodes out of adjustment or
defective.
Poor transformer high voltage
connections or defective
transformer.
Fuel oil filter clogged.
Defective oil pump.
Fuel oil line partially clogged or
contains air.
Blocked Vent Safety Circuit
opening intermittently. (Boiler
lights, then turns off)
Fuel oil leak.
Thermostat improperly adjusted or
in poor location.
Insufficient combustion air
adjustment at oil burner, or
improper draft pressure.
Heat exchanger partially clogged.
Flame impingement caused by
Incorrect nozzle angle.
Thermostat adjustments or
location.
Insufficient water flow.
Defective high limit control.
Under-sized nozzle.
Burner motor stopping
intermittently on overload.
Improper distribution of heat.
Remedy
• Check electrode settings. Check electrodes for dirt build-up or cracks in
porcelain.
• Check contacts between the igniter and electrodes. If OK, replace the igniter
• Replace fuel oil storage tank filter and / or fuel oil in-line filter.
• Check burner motor / fuel oil pump coupling. Check oil pump pressure.
Replace fuel oil pump if necessary.
• Bleed air from oil line. If problem persists, replace oil line.
• Check pressure switch on BVS to ensure it remains closed.
• Pressure switch open.
• Check pressure tubes for proper connection or possible obstructions.
• Check venting for blockage.
• Reduce burner head opening.
• Check combustion air intake for blockage.
• Check pressure switch operation.
• Check fuel oil line for leaks. Repair or replace if necessary.
• Check thermostat heat anticipator setting against measured amperage draw.
Increase heat anticipator setting if necessary. If the thermostat is being
influenced by drafts, sunlight, duct work, etc., relocate to more suitable
location.
• Check CO2. Should be 11.5% to 12%
• Check for soot build-up in heat exchanger flue passages, especially in the
outer radiator.
• Check nozzle size and angle. (See Appendix A). Check distance from head to
inside surface of the fire pot.
• Check thermostat heat anticipator setting against measured amperage draw.
Increase heat anticipator setting if necessary. If the thermostat is being
influenced by drafts, sunlight, duct work, etc., relocate to more suitable
location.
• Check all registers.
• Test high limit function of all limit switches. Use a duct thermometer to assess
accuracy of limit control. Replace control if necessary.
• Check nozzle and nozzle filter for dirt.
• Check burner motor. Pressure switch opening due to blocked vent. Replace if
necessary.
• This is not likely to be a Boiler problem. Balance duct system.
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P/N 240009355, Rev. C [11/15/2015]