Watts Aerco Benchmark OMM-0117 Operation And Maintenance Manual page 74

Benchmark 5000-6000 Operation & Maintenance Manual
SECTION 5 – TROUBLESHOOTING GUIDE
TABLE 5-1: Boiler Troubleshooting Procedures
FAULT
INDICATION
Actuator not allowing for full closure of gas
1.
valve.
SSOV powered when it should not be.
2.
SSOV
SWITCH OPEN
Defective switch or Actuator.
3.
Incorrectly wired switch.
4.
Air/Fuel Valve out of calibration.
1.
Air/Fuel Valve unplugged.
2.
STEPPER
3. Loose wiring connection to the stepper motor.
MOTOR
FAILURE
Defective Air/Fuel Valve stepper motor.
4.
Defective Power Supply Board or fuse.
5.
Defective IGST Board.
6.
SSOV didn't open
1.
SSOV FAULT
DURING
IGNITION
OMM-0118_B • GF-203 • 5/9/2019
PROBABLE CAUSES
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
CORRECTIVE ACTION
Observe operation of the Safety Shut-Off Valve (SSOV) through
1.
indicator on the Valve actuator and ensure that the valve is fully
and not partially closing.
If the SSOV never closes, it may be powered continuously. Close
2.
the gas supply and remove power from the unit. Refer fault to
qualified service personnel.
Remove the electrical cover from the SSOV and check switch
3.
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.
Refer to C-More User Manual, OMM-0032 (GF-112) and perform
1.
the Stepper Feedback Calibration procedure in Section 6.2.1 in
that manual.
Check that the Air/Fuel Valve is connected to the C-More
2.
Controller.
.Inspect for loose connections between the Air/Fuel Valve motor
3.
and the wiring harness.
Replace stepper motor.
4.
Check DS1 & DS2 LEDs on Power Supply Board. If they are not
5.
steady ON, replace Power Supply Board.
Check "Heartbeat" LED DS1 and verify it is blinking ON & OFF
6.
every second. If not, replace IGST Board.
Check pilot assembly for carbon buildup.
1.
Check scanners sensed pilot flame.
2.
Check power through ignition relay.
3.
Scanners close neutral side of relay coil.
4.
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