Benchmark 2.0 LN Installation, Operation & Maintenance Manual
CHAPTER 8 – TROUBLESHOOTING GUIDE
OMM-0046_0J AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 103 of 168
GF-123 Ph.: 800-526-0288 06/18/2015
TABLE 8-1. BOILER TROUBLESHOOTING (Continued)
STEPPER MOTOR
FAILURE
1. Air/Fuel Valve out of calibration.
2. Air/Fuel Valve unplugged.
3. Loose wiring connection to the
stepper motor.
4. Defective Air/Fuel Valve stepper
motor.
5. Defective Power Supply Board or
fuse
6. Defective IGST Board
1. Refer to GF-112 and perform Stepper Test (para. 6.3.5) to
ensure stepper motor rotates properly between the 0%
(fully closed) and 100% (fully open) positions. Verify that
the VALVE POSITION bargraph and the dial on the
Air/Fuel Valve track each other to indicate proper
operation. If operation is not correct, perform the Stepper
Feedback Calibration (GF-112, paragraph 6.2.1).
2. Check that the Air/Fuel Valve is connected to the Control
Box.
3. Inspect for loose connections between the Air/Fuel motor
and the wiring harness.
4. Replace stepper motor.
5. Check DS1 & DS2 LEDs on Power Supply Board. If they
are not steady ON, replace Power Supply Board
6. Check “Heartbeat” LED DS1 and verify it is blinking ON &
OFF every second. If not, replace IGST Board
To Next Page
Loading...
Need help?
General