Benchmark 750-3000 Boiler Operation, Service, Maintenance Guide - KOREA
SECTION 5 – TROUBLESHOOTING GUIDE
Page
66
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
PRG SWTCH
CLOSED
DURING
IGNITION
1.
A/F Valve rotated open to purge and did not
rotate to ignition position.
1.
Start the unit. The Air/Fuel Valve should rotate to the purge (open)
position, then back to ignition position (towards closed) during the
ignition cycle. If the valve does not rotate back to the ignition
position, check the Air/Fuel Valve calibration. If calibration is okay,
the problem may be in the Air/Fuel Valve or the C-More Controller.
Refer fault to qualified service personnel.
2.
Defective or shorted switch.
3.
Switch wired incorrectly.
4.
Defective Power Supply Board or fuse.
5.
Defective IGST Board.
2.
If the Air/Fuel Valve does rotate to the ignition position, check the
purge switch for continuity between the N.O. and COM terminals. If
the switch shows continuity when not in contact with the cam, check
to ensure that the switch is wired correctly (correct wire numbers on
the normally open terminals).
3.
If the switch is wired correctly, replace the switch.
4.
Check DS1 & DS2 LEDs on Power Supply Board. If they are not
steady ON, replace Power Supply Board.
5.
Check “Heartbeat” LED DS1 and verify it is blinking ON & OFF
every second. If not, replace IGST Board.
PRG SWTCH
OPEN
DURING
PURGE
1.
Defective Purge
switch.
2.
No voltage present at switch.
3.
Switch wired incorrectly.
4.
Defective Power Supply Board or fuse
5.
Defective IGST Board.
1.
If the air-fuel valve does rotate, check Purge
switch for continuity
when closing. Replace switch if continuity does not exist.
2.
Measure for 24 VAC from each side of the switch to ground. If
24VAC is not present, refer fault to qualified service personnel.
3.
Check to ensure that the switch is wired correctly (correct wire
numbers on the normally open terminals).
4.
Check DS1 & DS2 LEDs on Power Supply Board. If they are not
steady ON, replace Power Supply Board.
5.
Check “Heartbeat” LED DS1 and verify it is blinking ON & OFF
every second. If not, replace IGST Board.
OUTDOOR
TEMP
SENSOR
FAULT
1.
Loose or broken wiring.
2.
Defective Sensor.
3.
Incorrect Sensor.
1.
Inspect Outdoor Temperature sensor for loose or broken wiring.
2.
Check resistance of sensor to determine if it is within specification.
3.
Ensure that the correct sensor is installed.
