Instruction Manual

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 8 – TROUBLESHOOTING GUIDE
OMM-0082_0J AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 103 of 192
GF-130 Ph.: 800-526-0288 05/21/2014
Table 8-1 BOILER TROUBLESHOOTING
FAULT INDICATION PROBABLE CAUSES CORRECTIVE ACTION
AIRFLOW FAULT
DURING IGNITION
1. Blower stopped running due to thermal
or current overload.
2. Blocked Blower inlet or inlet air filter.
3. Blockage in Blower Proof switch.
4. Blockage in Blocked Inlet switch.
5. Defective Blower Proof switch.
6. Defective Blocked Inlet switch.
7. Loose temperature to AUX connection
in I/O Box.
8. Defective temperature sensor.
9. Loose wire connection between the
0-10V signal from I/O box to the
Blower input.
10. Defective I/O Box.
11. Wrong 0-10V output selection on the
control box.
12. Defective Air-Fuel Valve
potentiometer.
13. Hard light.
1. Check combustion blower for signs of excessive heat or high
current drain that may trip thermal or current overload devices.
2. Inspect the inlet to the combustion blower including the air filter
at the air/fuel valve for signs of blockage.
3.
Remove the Blower Proof switch and inspect for signs of
blockage, clean or replace as necessary.
4. Remove the Blocked
Inlet switch and inspect for signs of
blockage, clean or replace as necessary.
5. Check the continuity of the Blower Proof switch with the blower
running. If the resistance reading is erratic or is greater than
zero ohms, replace the switch.
6. Turn off
unit and check the continuity of the Blocked Inlet
switch. If the resistance reading is erratic or
is greater than
zero ohms, replace the switch.
7. Check the actual inlet air temperature and measure voltage at
AUX input in the I/O Box. Verify that the voltag
e conforms to
the values shown in the tabular listing provided in Appendix C.
8.
Refer to CORRECTIVE ACTION 7 and verify that the voltage
conforms to the values shown in Appendix C.
9. Check wire connection from I/O Box 0-10V signal to the Blower
Motor.
10. Measure voltage at the I/O box 0-
10V output. A voltage of
8.2V equates to a 100% open valve position.
11. Check the Analog Out option on the C-
More Configuration
Menu. Valve Position 0-10V should be selected.
12.
Check Air/Fuel Valve position at 0%, 50% and 100% open
posi
tions. The positions on the VALVE POSITION bargraph
should match the readings on the Air/Fuel Valve dial.
13. Check igniter-injector for soot or erosion of electrode. Check
injector solenoid valve to insure proper open/close operation.