Instruction Manual

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 8 – TROUBLESHOOTING GUIDE
Page 108 of 192 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0082_0J
05/21/2014 Ph.: 800-526-0288 GF-130
TABLE 8-1. BOILER TROUBLESHOOTING – Continued
FAULT INDICATION
PROBABLE CAUSES
CORRECTIVE ACTION
IGN SWTCH CLOSED
DURING PURGE
1. Air/Fuel Valve not rotating
2. Defective or shorted switch
3. Switch wired incorrectly
4. Defective Power Supply Board
or fuse
5. Defective IGST Board
1. Start the unit. The Air/Fuel Valve should rotate to the purge
(open) position. If the valve does not rotate at all or does
not rotate fully open, check the Air/Fuel Valve calibration.
If calibration is okay, the problem may be in the Air-Fuel
Valve or the Control Box. Refer to qualified service
personnel
2. .If the Air/Fuel Valve does rotate to purge, check the
ignition switch for continuity between the N.O. and COM
terminals. If the switch shows continuity when not in
contact with the cam replace the switch.
3. Check to ensure that the switch is wired correctly (correct
wire numbers on the normally open terminals). 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
IGN SWTCH OPEN
DURING IGNITION
1. Air/Fuel Valve not rotating to
ignition position.
2. Defective ignition switch
3. Defective Power Supply Board
or fuse
4. Defective IGST Board
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 Control Box. Refer fault to qualified
service personnel.
2. If the Air/Fuel Valve does rotate to the ignition position,
check the ignition position switch for continuity between the
N.O. and COM terminals when in contact with the cam.
3. Check DS1 & DS2 LEDs on Power Supply Board. If they
are not steady ON, replace Power Supply Board.
4. Check “Heartbeat” LED DS1 and verify it is blinking ON &
OFF every second. If not, replace IGST Board.