Watts AERCO Benchmark BMK750 Operation And Service Manual page 154

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 9 – TROUBLESHOOTING
TABLE 9-1: Boiler Troubleshooting Procedures
Fault Probable Causes
Edge [i] Controller signal type
3.
selection switches not set for
correct signal type (voltage or
current).
Defective Flame Detector.
1.
2. SSOV not fully closed.
RESIDUAL
FLAME
Wire strand from burner head in
3.
contact with Flame Detector
See SSOV SWITCH OPEN
SSOV
FAULT
DURING
PURGE
SSOV switch closed for 15
SSOV
seconds during run.
FAULT
DURING
RUN
1. SSOV relay failed on IGST
board.
Floating Neutral.
2.
SSOV
RELAY
FAILURE
Hot and Neutral reversed at
3.
SSOV.
Actuator not allowing for full
1.
closure of gas valve.
SSOV powered when it should
2.
SSOV
not be
SWITCH
OPEN
Defective switch or Actuator.
3.
OMM-0145_A99 • GF-218 • Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
9/18/2019
Corrective Action
Check DIP switch on PMC board to ensure it is
3.
set correctly for the type of signal being sent.
Check control signal type set in the Remote
Signal parameter (Advanced Setup→ Unit →
Application Configuration).
Replace Flame Detector.
1.
Check open/close indicator window of Safety
2.
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. 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.
Ensure Flame Detector is in good condition and
3.
is not tilted inward toward burner head.
Replace actuator.
1.
1. Press CLEAR button and restart unit. If fault
persists, replace Ignition/Stepper (IGST) Board.
The Neutral and Earth Ground are not
2.
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.
Observe operation of the Safety Shut-Off
1.
Valve (SSOV) through indicator on the Valve
actuator and ensure that the valve is fully and
not partially closing.
If the SSOV never closes, it may be powered
2.
continuously. Close the gas supply and
remove power from the unit. Refer fault to
qualified service personnel.
Remove the electrical cover from the SSOV
3.
and check switch continuity. If the switch does
not show continuity with the gas valve closed,
either adjust or replace the switch or actuator.
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