Aerco Benchmark BMK 750 User Manual page 67

Benchmark 750-3000 Boiler Operation, Service, Maintenance Guide - KOREA
SECTION 5 – TROUBLESHOOTING GUIDE
TABLE 5-1: Boiler Troubleshooting Procedures
Fault
Probable Causes
Indication
Combustion Calibration incorrect.
1.
O2 % OUT OF
Blocked inlet air duct or louver.
2.
RANGE
1. Internal recirculation pump failed.
RECIRC PUMP
FAILURE
Remote setpoint signal not present:
1.
Not yet installed.
Wrong polarity.
Signal defective at source.
REMOTE
Broken or loose wiring.
SETPT
Signal is not isolated (floating) if 4 to 20 mA.
2.
SIGNAL FAULT
C-More Controller signal type selection switches
3.
not set for correct signal type (voltage or current).
Defective Flame Detector.
1.
SSOV not fully closed.
2.
RESIDUAL
FLAME
See SSOV SWITCH OPEN
SSOV FAULT
DURING
PURGE
SSOV switch closed for 15 seconds during run.
SSOV FAULT
DURING RUN
OMM-0128_0C
GF-206-K
Corrective Action
Check Combustion Analyzer and recalibrate the boiler.
1.
Unblock air inlet and measure open area for combustion air to the
2.
room.
1. Replace recirculation pump.
Check I/O Box to ensure signal is hooked up.
1.
Hook up if not installed.
If installed, check polarity.
Measure signal level.
Check continuity of wiring between source and unit.
Check signal at source to ensure it is isolated.
2.
Check DIP switch on PMC board to ensure it is set correctly for the
3.
type of signal being sent. Check control signal type set in item 6 of the
Configuration menu (see Section 2.6: Configuration Menu).
Replace Flame Detector.
1.
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 Gas Shut-Off Valve downstream of SSOV (see Section 1,
Figure 1-1). 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.
Replace or adjust micro-switch in SSOV actuator. If fault persists,
1.
replace actuator.
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Ph.: 800-526-0288
Page 67 of 146
11/29/2017