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SECTION 9 TROUBLESHOOTING
TABLE 9-1: Boiler Troubleshooting Procedures
Fault
Probable Causes
Defective temperature sensor.
Loose wire connection between
the Blower and the Controller.
Defective Air-Fuel Valve
potentiometer.
Hard light.
Blower not running / too slow.
Defective Blocked Inlet switch.
Blockage in air filter or Blocked
Inlet switch.
AIRFLOW FAULT
Blocked blower inlet or inlet
DURING PURGE
ductwork.
No voltage to Blocked Inlet switch
from Edge Controller.
PROBABLE CAUSES from 3 to 12
for AIRFLOW FAULT DURING
IGNITION apply for this fault.
Missing or improperly connected
Blocked Flue jumper.
Blower stopped running due to
thermal or current overload.
Blocked Blower inlet or inlet
ductwork.
Blockage in air filter or Blocked
Inlet switch.
AIRFLOW FAULT
Defective Blocked Inlet switch.
DURING RUN
Combustion oscillations.
Probable causes from 3 to 16 for
AIRFLOW FAULT DURING
IGNITION applies for this fault.
Delayed Interlock Jumper not
properly installed or missing.
Device proving switch hooked to
DELAYED
interlocks is not closed.
INTERLOCK OPEN
Direct drive signal is not present:
Not yet installed.
DIRECT DRIVE
Wrong polarity.
Signal defective at source.
SIGNAL FAULT
Broken or loose wiring.
Signal is not isolated (floating).
•
Corrective Action
Refer to CORRECTIVE ACTION 7 and verify that the voltage
conforms to the values shown in the manual
Check wire connection from the Blower motor to the
Secondary Power Panel.
Check Air/Fuel Valve position at 0%, 50% and 100% open
positions. The positions on the Valve Position bar graph should
match the readings on the Air/Fuel Valve dial.
Check igniter-injector for soot or erosion of electrode. Check
injector solenoid valve to insure proper open/close operation.
Start the unit. If the blower does not run check the blower solid
state relay for input and output voltage. If the relay is OK,
check the blower.
Start the unit. If the blower runs, turn off unit and check the
Blocked Inlet switch for continuity. Replace the switch if
continuity does not exist.
Remove the air filter and Blocked Inlet switch and inspect for
signs of blockage. Clean or replace as necessary.
Inspect inlet to combustion blower including any ductwork
leading up to the combustion blower for signs of blockage.
During the start sequence, verify that 24 VAC is present
between each side of the switch and ground. If 24 VAC is not
present, refer fault to qualified service personnel.
See CORRECTIVE ACTIONS for AIRFLOW FAULT DURING
IGNITION, items 3 to 12.
Check auxiliary box to be sure Blocked Flue input is jumpered
and properly connected.
Check blower for signs of excessive heat or high current draw
that may trip thermal or current overload devices.
Inspect the inlet to the blower, including any ductwork leading
up to the combustion blower, for signs of blockage.
Remove the air filter and Blocked Inlet switch and inspect for
signs of blockage, clean or replace as necessary.
Verify 24 VAC is present between each side of the switch and
ground. If 24 VAC is not present at both sides, replace switch.
Run unit to full fire. If the unit rumbles or runs rough, perform
combustion calibration.
See CORRECTIVE ACTIONS from 3 to 12 for AIRFLOW FAULT
DURING IGNITION.
Check that jumper is properly installed across the Delayed
Interlock terminals in the I/O Box.
If there are 2 external wires on these terminals, check to see if
an end switch for a proving device (pump, louver, etc.) is tied to
these interlocks. Ensure that the device and/or its end switch is
functional. A jumper may be temporarily installed to test the
interlock.
Check I/O Box to ensure signal is hooked up.
Hook up if not installed.
If installed, check polarity.
Measure signal level.
Check wiring continuity between source and unit.
Check signal at source to ensure it is isolated.
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