AERCO BMK 1.5 LN Dual Fuel Jan 2009 - Manual (Page 64)

TROUBLESHOOTING
TABLE 8-1. BOILER TROUBLESHOOTING – Continued
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
(continued) 2. Defective ignition switch
3. Defective Power Supply Board or
fuse
4. Defective IGST Board
2. If the Air/Fuel Valve does rotate to the ignition position, check the
ignition position switch for continuity between the N.O. and COM
terminals when in contact with the cam.
3. Check DS1 & DS2 LEDs on Power Supply Board. If they are not
steady ON, replace Power Supply Board.
4. Check “Heartbeat” LED DS1 and verify it is blinking ON & OFF
every second. If not, replace IGST Board.
INTERLOCK
OPEN
1. Interlock jumper not installed or
removed
2. Energy Management System does
not have boiler enabled.
3. Device proofing switch hooked up to
interlocks is not closed.
1. Check for a jumper properly installed across the interlock
terminals in the I/O box
2. If there are two external wires on these terminals check any
Energy Management system to see if they have the units
disabled (a jumper may be temporarily installed to see if the
interlock circuit is functioning).
3. Verify that the proving switch for any device hooked to the
interlock circuit is closing and that the device is operational.
LINE VOLTAGE
OUT OF PHASE
1. Line and Neutral switched in AC
Power Box.
2. Incorrect power supply transformer
wiring.
1. Check hot and neutral in AC Power Box to ensure they are not
reversed
2. Check transformer wiring, in AC Power Box, against the power
box transformer wiring diagram to ensure it is wired correctly
LOW GAS
PRESSURE
1. Incorrect supply gas pressure.
2. Defective low gas pressure switch for
fuel being used
3. Fuel Selector Switch is in the OFF
position or was changed while the
unit was running.
1. Measure gas pressure upstream of the supply gas regulator with
the unit firing. Ensure it is 4” W.C. minimum at full fire. (see para.
2.7.1).
2. Measure gas pressure at the low gas pressure switch. If it is
greater than 2.6” W.C. for the fuel being used, measure
continuity across the switch and replace if necessary.
3. Check Fuel Selector Switch position.
8 -8