AERCO BMK 1500-2000 - Manual (Page 106)

Benchmark 1500 - 2000 Boilers
CHAPTER 8 – TROUBLESHOOTING GUIDE
Page 106 of 188
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
OMM-0097_0D
Ph.: 800-526-0288
GF-142
TABLE 8-1: BOILER TROUBLESHOOTING – Continued
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
(continued) 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.
O2 % OUT OF RANGE 1. Combustion Calibration incorrect.
2. Blocked inlet air duct or louver.
1. Check Combustion Analyzer and recalibrate the boiler.
2. Unblock air inlet and measure open area for combustion air to
the room.