Watts AERCO Edge CFR 3000 Operator's And Service Manual page 55

SECTION 9 TROUBLESHOOTING
TABLE 9-1: Boiler Troubleshooting Procedures
Fault Probable Causes
A/F Valve rotated open to purge
1.
and did not rotate to ignition
position.
Defective or shorted switch.
2.
PRG SWTCH
CLOSED DURING
IGNITION
Switch wired incorrectly.
3.
Defective Power Supply Board or
4.
fuse.
Defective IGST Board.
5.
Defective Purge switch.
1.
No voltage present at switch.
2.
PRG SWTCH Switch wired incorrectly.
3.
OPEN DURING
PURGE
Defective Power Supply Board or
4.
fuse.
Defective IGST Board.
5.
Loose or broken wiring.
1.
OUTDOOR TEMP
Defective Sensor.
2.
SENSOR FAULT
Incorrect Sensor.
3.
RECIRC PUMP Internal recirculation pump failed.
1.
FAILURE
•
Corrective Action
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 Edge
Controller. Refer fault to qualified service
personnel.
If the Air/Fuel Valve does rotate to the ignition
2.
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).
If the switch is wired correctly, replace the
3.
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.
If the air-fuel valve does rotate, check Purge
1.
switch for continuity when closing. Replace
switch if continuity does not exist.
Measure for 24 VAC from each side of the switch
2.
to ground. If 24VAC is not present, refer fault to
qualified service personnel.
Check to ensure that the switch is wired correctly
3.
(correct wire numbers on the normally open
terminals).
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.
Inspect Outdoor Temperature sensor for loose or
1.
broken wiring.
Check resistance of sensor to determine if it is
2.
within specification.
Ensure that the correct sensor is installed.
3.
1. Replace recirculation pump.
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