Watts AERCO Benchmark BMK750 Operation And Service Manual page 148

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 9 – TROUBLESHOOTING
TABLE 9-1: Boiler Troubleshooting Procedures
Fault Probable Causes
Delayed Interlock Jumper not
1.
properly installed or missing.
Device proving switch hooked
2.
DELAYED
to interlocks is not closed.
INTERLOC
K OPEN
Direct drive signal is not
1.
present:
•
Not yet installed.
•
Wrong polarity.
•
Signal defective at source.
DIRECT •
Broken or loose wiring.
DRIVE
Signal is not isolated
2.
SIGNAL
(floating).
FAULT
Edge [i] Controller signal type
3.
selection switches not set for
correct signal type (voltage or
current).
Worn Flame Detector.
1.
No spark from Spark Igniter.
2.
Defective Ignition
3.
Transformer.
FLAME
Defective Ignition/Stepper
4.
LOSS
(IGST) Board.
DURING
IGN
Defective SSOV.
5.
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Corrective Action
Check to insure jumper is properly installed
1.
across the Delayed Interlock terminals in the
I/O Box.
If there are 2 external wires on these
2.
terminals, check to see if an end switch for a
proving device (such as a pump, louver, etc.)
is tied 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.
1.
•
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.
2.
Check DIP switch on the Controller's Interface
3.
board to ensure it is set correctly for the type
of signal being sent. Check control signal type
set in Advanced Setup
Application Configuration screen.
Remove and inspect the Flame Detector for
1.
signs of wear. Replace if necessary.
Close the internal gas valve in the unit. Install
2.
and arc a spark igniter outside the unit.
If there is no spark, check for 120VAC at the
3.
primary side to the ignition transformer during
the ignition cycle.
If 120VAC is not present, the IGST Board in
4.
the Edge [i] Controller may be defective. Refer
fault to qualified service personnel.
While externally arcing the spark igniter,
5.
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 [i]
Controller may be defective. Refer fault to
qualified service personnel.
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