AERCO BMK 1.5 LN July 2011 - Manual (Page 87)

CHAPTER 7: MAINTENANCE
PR2: 05/09/12 Page 87 of 152
Benchmark 1.5LN Low NOx Boiler
Operation and Maintenance Manual
OMM-0041_0D
GF-120
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
TABLE 8-1. BOILER TROUBLESHOOTING (Continued)
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
FLAME LOSS
DURING IGN
(continued)
9. Unstable gas pressure.
10. Carbon or other debris on Burner.
11. Staged ignition solenoid valves
don’t open.
12. Clogged staged ignition piece.
9. Refer to “Gas Pressure Requirements” section of GF-2030:
BMK Gas Supply Design Guide.
10. Remove the burner and inspect for any carbon or debris.
Clean and reinstall.
11. When boiler goes to ignition, listen to the solenoid valves for
a clicking sound to ensure they are opening.
12. Remove and inspect staged ignition piece for blockage.
FLAME LOSS
DURING RUN
1. Worn Flame Detector or cracked
ceramic.
2. Defective Regulator.
3. Poor combustion calibration.
4. Debris on burner.
5. Blocked condensate drain.
1. Remove and inspect the Flame Detector for signs of wear or
cracked ceramic. Replace if necessary.
2. Check gas pressure readings using a gauge or manometer into
and out of the Air/Fuel Valve to ensure that the gas pressure
into and out of the valve is correct.
3. Check combustion calibration. Adjust as necessary.
4. Remove the burner and inspect for any carbon or debris. Clean
and reinstall.
5. Remove blockage in condensate drain.
HEAT DEMAND
FAILURE
1. The Heat Demand Relays on the
Ignition/Stepper board failed to
activate when commanded.
2. Relay is activated when not in
Demand
1. Press CLEAR button and restart the unit. If the fault persists,
replace Ignition/Stepper (IGST) Board.
2. Defective relay. Replace IGST Board.
HIGH EXHAUST
TEMPERATURE
1. Defective exhaust sensor.
2. Carboned heat exchanger due to
incorrect combustion calibration
1. Measure the actual exhaust temperature and continuity of the
exhaust sensor. If the exhaust temperature is less than 475 o
F and the exhaust sensor shows continuity replace the
sensor.
2. If exhaust temperature is greater than 500 o F, check
combustion calibration. Calibrate or repair as necessary.