AERCO BMK 3.0 LN Nat. Gas APRIL 2009 - Manual (Page 60)

TROUBLESHOOTING
TABLE 8-1. BOILER TROUBLESHOOTING – Continued
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
DELAYED
INTERLOCK OPEN
1. Delayed Interlock Jumper not
installed or removed.
2. Device proving switch hooked to
interlocks is not closed
1. Check for a jumper properly installed across the delayed
interlock terminals in the I/O box.
2. If there are 2 external wires on these terminals, check to see if
an end switch for a device such as a pump, louver, etc. is tied
these interlocks. Ensure that the device and or its end switch
are functional. (jumper may be temporarily installed to test
interlock)
DIRECT DRIVE
SIGNAL FAULT
1. Direct drive signal is not present:
Not yet installed.
Wrong polarity.
Signal defective at source.
Broken or loose wiring.
2. Signal is not isolated (floating).
3. Control Box signal type selection
switches not set for correct signal
type (voltage or current).
1. Check I/O Box to ensure signal is hooked up.
Hook up if not installed.
If installed, check polarity.
Measure signal level.
Check continuity of wiring between source and boiler.
2. Check signal at source to ensure it is isolated.
3. Check DIP switch on PMC board to ensure it is set correctly for
the type of signal being sent. Check control signal type set in
Configuration Menu.
FLAME LOSS
DURING IGN
1. Burner Ground Screw not installed
or loose.
2. Worn flame detector
3. No spark from Spark Plug
4. Defective Ignition Transformer
5. Defective Ignition/Stepper (IGST)
Board
6. Defective SSOV
1. Inspect and install/retighten Burner Ground Screw.
2. Remove and inspect the flame detector for signs of wear.
Replace if necessary.
3. Close the internal gas valve in the boiler. Install and arc a spark
ignitor outside the unit.
4. If there is no spark, check for 120VAC at the primary side to the
ignition transformer during the ignition cycle.
5. If 120VAC is not present, the IGST Board in the Control Box
may be defective. Refer fault to qualified service personnel.
6. While externally arcing the spark ignitor, 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
valves input terminals. If 120VAC is not present, the IGST
board in the Control Box may be defective. Refer fault to
qualified service personnel.
8 -4