Benchmark 750-3000 Boiler Operation, Service, Maintenance Guide - KOREA
SECTION 5 – TROUBLESHOOTING GUIDE
Page
68
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
SSOV RELAY
FAILURE
1.
SSOV relay failed on IGST board.
2.
Floating Neutral.
3.
Hot and Neutral reversed at SSOV.
1.
Press
CLEAR
button and restart unit. If fault persists, replace
Ignition/Stepper (IGST) Board.
2.
The Neutral and Earth Ground are not connected at the source and
therefore there is a voltage measured between the two. Normally this
measurement should be near zero or no more than a few millivolts.
3.
Check SSOV power wiring.
SSOV
SWITCH OPEN
1.
Actuator not allowing for full closure of gas
valve.
2.
SSOV powered when it should not be
3.
Defective switch or Actuator.
4.
Incorrectly wired switch.
1.
Observe operation of the Safety Shut-Off Valve (SSOV) through
indicator on the Valve actuator and ensure that the valve is fully and
not partially closing.
2.
If the SSOV never closes, it may be powered continuously. Close
the gas supply and remove power from the unit. Refer fault to
qualified service personnel.
3.
Remove the electrical cover from the SSOV and check switch
continuity. If the switch does not show continuity with the gas valve
closed, either adjust or replace the switch or actuator.
4.
Ensure that the SSOV Proof of Closure switch is correctly wired.
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 the C-More User Manual OMM-0032 (GF-112) and perform
the Stepper Feedback Calibration procedure in Section 6, Section
6.2.1.
2.
Check that the Air/Fuel Valve is connected to the C-More
Controller.
3.
Inspect for loose connections between the Air/Fuel Valve 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.