Aerco Benchmark BMK 750 User Manual page 62

Benchmark 750-3000 Boiler Operation, Service, Maintenance Guide - KOREA
SECTION 5 – TROUBLESHOOTING GUIDE
TABLE 5-1: Boiler Troubleshooting Procedures
Fault
Probable Causes
Indication
Worn Flame Detector or cracked ceramic.
1.
Defective Regulator.
2.
FLAME LOSS
Poor combustion calibration.
3.
DURING RUN
Debris on burner.
4.
Blocked condensate drain.
5.
The Heat Demand Relays on the
1.
HEAT
Ignition/Stepper (IGST) board failed to activate
DEMAND
when commanded.
FAILURE
Relay is activated when not in Demand.
2.
Poor combustion calibration.
1.
HIGH EXHAUST
TEMPERATURE
Carboned heat exchanger due to incorrect
2.
combustion calibration.
Incorrect supply gas pressure.
1.
Defective SSOV Actuator.
2.
HIGH GAS
PRESSURE
Defective High Gas Pressure switch.
3.
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Corrective Action
Remove and inspect the Flame Detector for signs of wear or
1.
cracked ceramic. Replace if necessary.
Check gas pressure readings using a gauge or manometer into and
2.
out of the Air/Fuel Valve to ensure that the gas pressure into and
out of the valve is correct.
Check combustion calibration using the procedure in Section 4-3 of
3.
the Benchmark 750 – 3000 Boiler Installation and Startup Guide
Guide, OMM-0127 (GF-205-K).
Remove the burner and inspect for any carbon build-up or debris.
4.
Clean and reinstall.
Remove blockage in condensate drain.
5.
Press CLEAR button and restart the unit. If the fault persists,
1.
replace Ignition/Stepper (IGST) Board.
Defective relay. Replace IGST Board.
2.
Check combustion calibration using procedure in Section 4.3 of the
1.
Benchmark 750 – 3000 Boiler Installation and Startup Guide Guide,
OMM-0127 (GF-205-K).
2. If exhaust temperature is greater than 200
combustion calibration. Calibrate or repair as necessary.
Check to ensure gas pressure at inlet of SSOV does not exceed
1.
14" W.C. (3.49 kPa).
If gas supply pressure downstream of SSOV Actuator cannot be
2.
lowered to the range specified in Table 4-1 (Natural Gas) of the
Benchmark 750 – 3000 Boiler Installation and Startup Guide Guide,
OMM-0127 (GF-205-K), the SSOV Actuator may be defective.
Remove the leads from the High Gas Pressure switch. Measure
3.
continuity across the common (C) and normally closed (NC)
terminals with the unit not firing. Replace the switch if continuity
does not exist.
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Ph.: 800-526-0288
o o
F (93.3 C), check
OMM-0128_0C
GF-206-K