Benchmark 2.0 LN Installation, Operation & Maintenance Manual
CHAPTER 8 – TROUBLESHOOTING GUIDE
Page
100
of
168
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
OMM-0046_0J
06/18/2015
Phone: 800-526-0288
GF-123
TABLE 8-1. BOILER TROUBLESHOOTING
(Continued)
FAULT
INDICATION
PROBABLE CAUSES
CORRECTIVE ACTION
INTERLOCK
OPEN
1.
Interlock jumper not installed or
removed
2.
Energy Management System
does not have boiler enabled.
3.
Device proving switch hooked 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.
Check that 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 Pressure Gas
Switch
1.
Measure gas pressure upstream of the supply gas regulator with the unit firing.
Refer to paragraph 2.7.1 to ensure that the gas pressure is correct for the type
of fuel and gas train being used.
2.
Measure gas pressure at the low gas pressure switch. If it is greater than 2.6”
W.C., measure continuity across the switch and replace if necessary
LOW WATER
LEVEL
1.
Insufficient water level in system
2.
Defective water level circuitry.
3.
Defective water level probe.
1.
Check system for sufficient water level.
2.
Test water level circuitry using the Control Box front panel LOW WATER TEST
and RESET buttons. Replace water level circuitry if it does not respond.
3.
Check continuity of probe end to the shell, change probe if there is no
continuity.
MODBUS
COMM FAULT
1.
Boiler not seeing information
from Modbus network
1.
Check network connections. If fault persists, contact qualified Service
Personnel.
PRG SWTCH
CLOSED
DURING
IGNITION
1.
A/F Valve rotated open to purge
and did not rotate to ignition
position.
1.
Start the unit. The Air/Fuel Valve should rotate to the purge (open) position,
then back to ignition position (towards closed) during the ignition cycle. If the
valve does not rotate back to the ignition position, check the Air/Fuel Valve
calibration. If calibration is okay, the problem may be in the Air/Fuel Valve or
the Control Box. Refer fault to qualified service personnel.
