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 111 of 192
GF-130 Ph.: 800-526-0288 05/21/2014
TABLE 8-1. BOILER TROUBLESHOOTING – Continued
FAULT INDICATION
PROBABLE CAUSES
CORRECTIVE ACTION
RECIRC PUMP FAILURE
1. Internal recirculation pump failed.
1. Replace recirculation pump.
REMOTE SETPT
SIGNAL FAULT
1.
Remote setpoint signal not
present:
Not yet installed.
Wrong polarity.
Signal defective at source.
Broken or loose wiring.
2. Signal is not isolated (floating) if 4
to 20 mA.
3. Control Box signal type selection
switches not set for correct signal
type (voltage or current).
1.
Check I/O Box to ensure signal is hooked up.
Hook up if not installed.
If installed, check polarity.
Measure signal level.
Check continuity of wiring between source and unit.
2. Check signal at source to ensure it is isolated.
3. Check DIP switch on PMC board to ensure it is set correctly for
the type of signal being sent. Check control signal type set in
Configuration Menu.
RESIDUAL
FLAME
1. Defective Flame Detector.
2. SSOV not fully closed.
1. Replace Flame Detector.
2. Check open/close indicator window of Safety Shut-Off Valve
(SSOV) and ensure that the SSOV is fully closed. If not fully
closed, replace the valve and or actuator. Close the 1” Gas Shut-
Off Valve downstream of SSOV (Figure 6-1). Install a manometer
or gauge at the leak detection port between the SSOV and Gas
Shut Off Valve. If a gas pressure reading is observed replace the
SSOV Valve and/or Actuator.
SSOV FAULT DURING
PURGE
See SSOV SWITCH OPEN
SSOV FAULT
DURING RUN
SSOV switch closed for 15 seconds
during run.
1. Replace or adjust micro-switch in SSOV actuator. If fault persists,
replace actuator.
SSOV RELAY
FAILURE
1. SSOV relay failed on IGST board.
2. Floating Neutral.
3. Hot and Neutral reversed at
SSOV.
1. Press CLEAR button and restart unit. If fault persists, replace
Ignition/Stepper (IGST) Board.
2. The Neutral and Earth Ground are not connected at the source
and therefore there is a voltage measured between the two.
Normally this measurement should be near zero or no more than a
few millivolts.
3. Check SSOV power wiring.