Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 9
– TROUBLESHOOTING
OMM-0145_A99
• GF-218 • 9/18/2019 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page
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of
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TABLE 9-1: Boiler Troubleshooting Procedures
Fault
Probable Causes
Corrective Action
TEMP
SWITCH
OPEN
2.
Incorrect PID settings.
2.
Check PID settings (
Advanced Setup
→
Performance
→
Temperature
Control
, first 3
items). If the settings have been changed,
record the current readings then reset to
default values.
3.
Faulty shell temperature
sensor.
3.
Using the resistance charts in Section 2 of the
Benchmark 750-6000 with Edge [i]: Reference
Manual (OMM-0146, GF-219)
measure the
resistance of Shell sensor and BTU sensor at
a known water temperature.
4.
Unit in
Manual
mode.
4.
If unit is in
Manual
mode, switch to
Auto
mode (
Diagnostic
→
Manual Mode
).
5.
Unit setpoint is greater than
Over Temperature switch
setpoint.
5.
Check setpoint of unit and setpoint of
Temperature switch; Ensure that the
temperature switch is set higher than the unit’s
setpoint.
6.
System flow rate changes are
occurring faster than units can
respond.
6.
If the system is a variable flow system,
monitor system flow changes to ensure that
the rate of flow change is not faster than what
the units can respond to.
HIGH WATER
TEMPERATU
RE
1.
See HIGH WATER
TEMPERATURE SWITCH
OPEN.
1.
See HIGH WATER TEMPERATURE SWITCH
OPEN.
2.
Temp HI Limit setting is too
low.
2.
Check Temp HI Limit setting.
IGN BOARD
COMM
FAULT
1.
Communication fault has
occurred between the PMC
board and Ignition/Stepper
(IGST) board.
1.
Press
CLEAR
button and restart unit. If fault
persists, contact qualified Service Personnel.
2.
32 Pin Ribbon cable defective.
2.
Replace 32 Pin Ribbon cable.
IGN
SWITCH
CLOSED
DURING
PURGE
1.
Air/Fuel Valve not rotating.
1.
Start the unit. The Air/Fuel Valve should rotate
to the purge (open) position. If the valve does
not rotate at all or does not rotate fully open,
check the Air/Fuel Valve calibration. If
calibration is okay, the problem may be in the
Air-Fuel Valve or the Edge [i] Controller. Refer
to qualified service personnel.
2.
Defective or shorted switch.
2.
If the Air/Fuel Valve does rotate to purge,
check the ignition switch for continuity
between the N.O. and COM terminals. If the
switch shows continuity when not in contact
with the cam replace the switch.