Watts AERCO CFR 1500 Operation And Service Manual page 49

SECTION 9 TROUBLESHOOTING
TABLE 9-1: Boiler Troubleshooting Procedures
Fault Probable Causes
Edge Controller signal type
selection switches not set for
correct signal type (voltage or
current).
Worn Flame Detector.
No spark from Spark Igniter.
Defective Ignition Transformer.
FLAME LOSS
Defective Ignition/Stepper (IGST)
DURING IGN
Board.
Defective SSOV.
Worn Flame Detector or cracked
ceramic.
Defective Regulator.
FLAME LOSS
DURING RUN Poor combustion calibration.
Debris on burner.
Blocked condensate drain.
The Heat Demand Relays on the
Ignition/Stepper (IGST) board
failed to activate when
HEAT DEMAND
FAILURE commanded.
Relay activated when not in
Demand.
Poor combustion calibration.
HIGH EXHAUST
TEMPERATURE
Carboned heat exchanger due to
incorrect combustion calibration.
Incorrect supply gas pressure.
Defective SSOV Actuator.
HIGH GAS
PRESSURE
Defective High Gas Pressure
switch.
Faulty Water temperature switch.
HIGH WATER
TEMP SWITCH Incorrect PID settings.
OPEN
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Corrective Action
Check DIP switch on the Controller's Interface board to ensure
it is set correctly for the type of signal being sent. Check
control signal type set in Advanced Setup > BST Cascade >
Application Configuration screen.
Remove and inspect the Flame Detector for signs of wear.
Replace if necessary.
Close the internal gas valve in the unit. Install and arc a spark
igniter outside the unit.
If there is no spark, check for 120VAC at the primary side to the
ignition transformer during the ignition cycle.
If 120VAC is not present, the IGST Board in the Edge Controller
may be defective. Refer fault to qualified service personnel.
While externally arcing the spark igniter, observe the
open/close indicator in the Safety Shut-Off Valve to ensure it is
opening. If the valve does not open, check for 120VAC at the
valve input terminals. If 120VAC is not present, the IGST board
in the Edge Controller may be defective. Refer fault to qualified
service personnel.
Remove and inspect the Flame Detector for signs of wear or
cracked ceramic. Replace if necessary.
Check gas pressure readings using a gauge or manometer into
and out of the Air/Fuel Valve to ensure that the gas pressure
into and out of the valve is correct.
Check combustion calibration using the procedures in Section
4.4: Combustion Calibration of this guide.
Remove the burner and inspect for any carbon build-up or
debris. Clean and reinstall.
Remove blockage in condensate drain.
Press CLEAR button and restart the unit. If the fault persists,
replace Ignition/Stepper (IGST) Board.
Defective relay. Replace IGST Board.
Check combustion calibration using procedures in Section 4.4:
Combustion Calibration of this guide.
If exhaust temperature is greater than 200
combustion calibration. Calibrate or repair as necessary.
Check to ensure gas pressure at inlet of SSOV does not exceed
14" W.C. (3.49 kPa).
If gas supply pressure downstream of SSOV Actuator cannot be
lowered to the range specified in Table 4-1 (Natural Gas) in
Section 4.4: Combustion Calibration of this guide; the SSOV
Actuator may be defective.
Remove the leads from the High Gas Pressure switch. Measure
continuity across the common (C) and normally closed (NC)
terminals with the unit not firing. Replace the switch if
continuity does not exist.
Test the temperature switch to insure it trips at its actual water
temperature setting.
Check PID settings (Advanced Setup > Performance >
Temperature Control). If the settings have been changed,
record the current readings then reset to default values.
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o o
F (93.3 C), check