Watts AERCO Edge CFR 3000 Operator's And Service Manual page 53

SECTION 9 TROUBLESHOOTING
TABLE 9-1: Boiler Troubleshooting Procedures
Fault Probable Causes
Unit setpoint is greater than Over
5.
Temperature switch setpoint.
System flow rate changes are
6.
occurring faster than units can
respond.
See HIGH WATER TEMPERATURE
1.
HIGH WATER
SWITCH OPEN.
TEMPERATURE
Temp HI Limit setting is too low.
2.
Communication fault has occurred
1.
IGN BOARD between the PMC board and
Ignition/Stepper (IGST) board.
COMM FAULT
32 Pin Ribbon cable defective.
2.
Air/Fuel Valve not rotating.
1.
Defective or shorted switch.
2.
IGN SWITCH
CLOSED DURING
PURGE
Switch wired incorrectly.
3.
Defective Power Supply Board or
4.
fuse.
Defective IGST Board.
5.
Air/Fuel Valve not rotating to
1.
ignition position.
IGN SWTCH
OPEN DURING
IGNITION
•
Corrective Action
Check setpoint of unit and setpoint of
5.
Temperature switch; Ensure that the
temperature switch is set higher than the unit's
setpoint.
If the system is a variable flow system, monitor
6.
system flow changes to ensure that the rate of
flow change is not faster than what the units can
respond to.
See HIGH WATER TEMPERATURE SWITCH OPEN.
1.
Check Temp HI Limit setting.
2.
Press CLEAR button and restart unit. If fault
1.
persists, contact qualified Service Personnel.
Replace 32 Pin Ribbon cable.
2.
Start the unit. The Air/Fuel Valve should rotate to
1.
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 Edge Controller. Refer to qualified service
personnel.
If the Air/Fuel Valve does rotate to purge, check
2.
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.
Check to ensure that the switch is wired correctly
3.
(correct wire numbers on the normally open
terminals). If the switch is wired correctly,
replace the switch.
Check DS1 & DS2 LEDs on Power Supply Board. If
4.
they are not steady ON, replace Power Supply
Board.
Check "Heartbeat" LED DS1 and verify it is
5.
blinking ON & OFF every second. If not, replace
IGST Board.
Start the unit. The Air/Fuel Valve should rotate to
1.
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 Controller.
Refer fault to qualified service personnel.
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