Benchmark 750-3000 Boiler Operation, Service, Maintenance Guide - KOREA
SECTION 5 – TROUBLESHOOTING GUIDE
Page
62
of
144
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
OMM-0128_0B
07/17/2017
Ph.: 800-526-0288
TABLE 5-1: Boiler Troubleshooting Procedures
Fault
Indication
Probable Causes
Corrective Action
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 using the procedure in Section 4-3 of
the
Benchmark 750 – 3000 Boiler Installation and Startup Guide
Guide
, OMM-0127 (GF-205-K).
4.
Remove the burner and inspect for any carbon build-up or debris.
Clean and reinstall.
5.
Remove blockage in condensate drain.
HEAT
DEMAND
FAILURE
1.
The Heat Demand Relays on the
Ignition/Stepper (IGST) 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.
Poor combustion calibration.
2.
Carboned heat exchanger due to incorrect
combustion calibration.
1.
Check combustion calibration using procedure in Section 4.3 of the
Benchmark 750 – 3000 Boiler Installation and Startup Guide Guide
,
OMM-0127 (GF-205-K).
2.
If exhaust temperature is greater than 200
o
F (93.3
o
C), check
combustion calibration. Calibrate or repair as necessary.
HIGH GAS
PRESSURE
1.
Incorrect supply gas pressure.
2.
Defective SSOV Actuator.
3.
Defective
High Gas Pressure
switch.
1.
Check to ensure gas pressure at inlet of SSOV does not
exceed
14” W.C. (3.49 kPa)
.
2.
If gas supply pressure downstream of SSOV Actuator cannot be
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.
3.
Remove the leads from the High Gas Pressure switch. Measure
continuity across the common (C) and normally closed (NC)
terminals with the unit not firing. Replace the switch if continuity
does not exist.
