Watts Aerco BMK 750, Operation And Service Manual

Page: 151 / 157

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 9
– TROUBLESHOOTING
OMM-0145_A99
• GF-218 • 9/18/2019 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page
151 of 157
TABLE 9-1: Boiler Troubleshooting Procedures
Fault Probable Causes Corrective Action
3.
Switch wired incorrectly.
3.
Check to ensure that the switch is wired
correctly (correct wire numbers on the
normally open terminals). If the switch is wired
correctly, replace the switch.
4.
Defective Power Supply Board
or fuse.
4.
Check DS1 & DS2 LEDs on Power Supply
Board. If they are not steady
ON , replace
Power Supply Board.
5.
Defective IGST Board.
5.
Check “Heartbeat” LED DS1 and verify it is
blinking
ON & OFF every second. If not,
replace IGST Board.
IGN
SWTCH
OPEN
DURING
IGNITION
1.
Air/Fuel Valve not rotating to
ignition position.
1.
Start the unit. The Air/Fuel Valve should rotate
to the purge (open) 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
Controller. Refer fault to qualified service
personnel.
2.
Defective Ignition switch.
2.
If the Air/Fuel Valve does rotate to the ignition
position, check the ignition position switch for
continuity between the N.O. and COM
terminals when in contact with the cam.
3.
Defective Power Supply Board
or fuse.
3.
Check DS1 & DS2 LEDs on Power Supply
Board. If they are not steady ON, replace
Power Supply Board.
4.
Defective IGST Board.
4.
Check “Heartbeat” LED DS1 and verify it is
blinking ON & OFF every second. If not,
replace IGST Board.
INTERLOC
K OPEN
1.
Interlock jumper not installed
or removed.
1.
Check for a jumper properly installed across
the interlock terminals in the I/O box.
2.
Energy Management System
does not have unit enabled.
2.
If there are two external wires on these
terminals check any 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.
Device proving switch hooked
to interlocks is not closed.
3.
Check that proving switch for any device
hooked to the interlock circuit is closing and
that the device is operational.
LINE
VOLTAGE
1.
Line and Neutral switched in
AC Power Box.
1.
Check hot and neutral in AC Power Box to
ensure they are not reversed.