Watts Aerco Benchmark OMM-0117 Operation And Maintenance Manual page 70

Benchmark 5000-6000 Operation & Maintenance Manual
SECTION 5 – TROUBLESHOOTING GUIDE
TABLE 5-1: Boiler Troubleshooting Procedures
FAULT
INDICATION
Air/Fuel Valve not rotating to ignition position.
1.
IGN SWTCH
OPEN
Defective Ignition switch.
2.
DURING
IGNITION
Defective Power Supply Board or fuse.
3.
Defective IGST Board.
4.
Interlock jumper not installed or removed.
1.
Energy Management System does not have
2.
INTERLOCK unit enabled.
OPEN
3. Device proving switch hooked to interlocks is
not closed.
Line and Neutral switched in AC Power Box.
1.
LINE VOLTAGE
OUT OF PHASE
2. Incorrect power supply transformer wiring.
Incorrect supply gas pressure.
1.
GAS
PRESSURE
FAULT
(Due to Low Gas
Defective Low Gas Pressure switch.
2.
Pressure)
OMM-0118_B • GF-203 • 5/9/2019
PROBABLE CAUSES
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
CORRECTIVE ACTION
Start the unit. The Air/Fuel Valve should rotate to the purge (open)
1.
position, then back to ignition position (towards closed) during the
ignition cycle. If the valve does not rotate back to the ignition
position, check the Air/Fuel Valve calibration. If calibration is okay,
the problem may be in the Air/Fuel Valve or the C-More Controller.
Refer fault to qualified service personnel.
If the Air/Fuel Valve does rotate to the ignition position, check the
2.
ignition position switch for continuity between the N.O. and COM
terminals when in contact with the cam.
Check DS1 & DS2 LEDs on Power Supply Board. If they are not
3.
steady ON, replace Power Supply Board.
Check "Heartbeat" LED DS1 and verify it is blinking ON & OFF
4.
every second. If not, replace IGST Board.
Check for a jumper properly installed across the interlock terminals
1.
in the I/O box.
If there are two external wires on these terminals check any
2.
Energy Management system to see if they have the units disabled
(a jumper may be temporarily installed to see if the interlock circuit
is functioning).
3. Check that proving switch for any device hooked to the interlock
circuit is closing and that the device is operational.
Check hot and neutral in AC Power Box to ensure they are not
1.
reversed.
2. Check transformer wiring, in AC Power Box, against the power box
transformer wiring diagram to ensure it is wired correctly.
Measure NATURAL GAS pressure upstream of the SSOV
1.
Actuator(s) with the unit firing. The minimum is 14" W.C.
although the BMK 6000 can operate with derating at 11" W.C. (2.7
kPa) and the BMK 5000 can operate with derating at 10" W.C.
(2.5 kPa) .
Measure NATURAL GAS pressure at the Low Gas Pressure
2.
switch. If it is greater than 10" W.C. (2.5 Pa), measure continuity
across the switch and replace if necessary.
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(3.5 kPa),