Benchmark 750-3000 Operation, Service & Maintenance Guide-Latin America
SECTION 5 – TROUBLESHOOTING GUIDE
OMM-0132A
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
Page
63
of
162
GF-206-LA-LA
Ph.: 800-526-0288
01/02/2018
TABLE 5-1: Boiler Troubleshooting Procedures
Fault
Indication
Probable Causes
Corrective Action
HIGH WATER
TEMP
SWITCH OPEN
1.
Faulty Water temperature switch.
2.
Incorrect PID settings.
3.
Faulty shell temperature sensor.
4.
Unit in MANUAL mode.
5.
Unit setpoint is greater than Over Temperature
switch setpoint.
6.
System flow rate changes are occurring faster
than units can respond.
1.
Test the temperature switch to insure it trips at its actual water
temperature setting.
2.
Check PID settings (see Section 2-7:
Tuning Menu,
items 1 -3, for
details). If the settings have been changed, record the current
readings then reset them to the default values.
3.
Using the resistance charts in Appendix C, measure the resistance
of Shell sensor and BTU sensor at a known water temperature.
4.
If unit is in MANUAL mode, switch to AUTO mode.
5.
Check setpoint of unit and setpoint of Temperature switch; Ensure
that the temperature switch is set higher than the unit’s setpoint.
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
TEMPERATURE
1.
See HIGH WATER TEMPERATURE SWITCH
OPEN.
2.
Temp HI Limit setting is too low.
1.
See HIGH WATER TEMPERATURE SWITCH OPEN.
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.
