AERCO BMK 2.0 LN Natural Gas 2008 - Manual (Page 57)

TROUBLESHOOTING
8 -5
TABLE 8-1. BOILER TROUBLESHOOTING – Continued
FAULT INDICATION PROBABLE CAUSES TROUBLESHOOTING/CORRECTIVE ACTION
(continued) 8. Defective staged ignition solenoid
valve.
9. Clogged staged ignition piece.
10. Carbon or other debris on burner
8. When boiler goes to ignition, listen to solenoid valve to ensure it
is opening.
9. Remove and inspect staged ignition piece for blockage.
10. Remove the burner and inspect for any carbon or debris. Clean
and reinstall
FLAME LOSS
DURING RUN
1. Worn Flame Detector or cracked
ceramic.
2. Poor combustion calibration.
3. Debris on burner.
4. Blocked condensate drain.
5. VFD faulting.
1. Remove and inspect the Flame Detector for signs of wear or
cracked ceramic. Replace if necessary.
2. Check combustion calibration. Adjust as necessary.
3. Remove the burner and inspect for any carbon or debris. Clean
and reinstall.
4. Remove blockage in condensate drain.
5. See Table 8-4 for VFD settings and faults.
HEAT DEMAND
FAILURE
1. The Heat Demand Relays on the
Ignition/Stepper board failed to
activate when commanded
2. Relay is activated when not in
Demand
1. Press CLEAR button and restart the unit. If the fault persists,
replace Ignition/Stepper (IGST) Board.
2. Defective relay. Replace IGST Board.
HIGH GAS
PRESSURE
1. Incorrect supply gas pressure.
2. Defective SSOV Supply Regulator.
3. Defective High Gas Pressure Switch
4. Gas pressure snubber not installed.
5. Fluctuating supply gas pressure.
1. Check to ensure gas pressure at inlet of SSOV is 2 psig
maximum.
2. If gas supply pressure downstream of SSOV cannot be lowered,
to 2.8” W.C. (see para. 4.3, step 10), the SSOV Supply
Regulator may be defective.
3. Remove the leads from the high gas pressure switch and
measure continuity across the common and normally closed
terminals with the unit not firing. Replace the switch if it does not
show continuity.
4. See Figure 8-1. Ensure that the gas pressure snubber is
installed at the high gas pressure switch.
5. Measure gas pressure upstream of SSOV and monitor for
sudden changes (see Fig. 8-1).