Aerco BENCHMARK 2500DF User Manual page 110

Benchmark 2500DF-3000DF Installation, Operation & Maintenance Manual
FAULT INDICATION
IGN SWTCH CLOSED
DURING PURGE
IGN SWTCH OPEN
DURING IGNITION
Page 110 of 234
05/21/2014
CHAPTER 8 – TROUBLESHOOTING GUIDE
TABLE 8-1: BOILER TROUBLESHOOTING – Continued
PROBABLE CAUSES
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
Air/Fuel Valve not rotating to
1.
ignition position.
Defective ignition switch
2.
3. Defective Power Supply Board or
fuse
4. Defective IGST Board
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Phone: 800-526-0288
CORRECTIVE ACTION
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
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.
OMM-0099_0A
GF-145