Watts AERCO Benchmark BMK5000 Operation And Service Manual page 136

Benchmark Platinum-Edge [ii]: Operation-Service Manual
SECTION 6 – TROUBLESHOOTING
TABLE 10-1: Boiler Troubleshooting Procedures
Fault Probable Causes
Faulty Water temperature switch.
1.
Incorrect PID settings.
2.
Faulty shell temperature sensor.
3.
HIGH WATER
TEMP SWITCH
OPEN
Unit in Manual mode.
4.
Unit setpoint is greater than Over Temperature
5.
switch setpoint.
System flow rate changes are occurring faster
6.
than units can respond.
See HIGH WATER TEMPERATURE SWITCH
1.
HIGH WATER
OPEN.
TEMPERATURE
Temp HI Limit setting is too low.
2.
Communication fault has occurred between the
1.
IGN BOARD
PMC board and Ignition/Stepper (IGST) board.
COMM FAULT
32 Pin Ribbon cable defective.
2.
Air/Fuel Valve not rotating.
1.
IGN SWITCH
CLOSED
DURING
PURGE
OMM-0137_J • Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
12/20/2022
Corrective Action
Test the temperature switch to insure it trips at its actual water
1.
temperature setting.
Check PID settings (Advanced Setup → Performance →
2.
Temperature Control, first 3 items). If the settings have been
changed, record the current readings then reset to default values.
Using the resistance charts in Section 2 of the Benchmark
3.
Platinum-Edge: REFERENCE Manual (GF-212) measure the
resistance of Shell sensor and BTU sensor at a known water
temperature.
If unit is in Manual mode, switch to Auto mode (Diagnostic →
4.
Manual Run, set Manual Mode = Enabled).
Check setpoint of unit and setpoint of Temperature switch; Ensure
5.
that the temperature switch is set higher than the unit's setpoint.
If the system is a variable flow system, monitor system flow
6.
changes to ensure that the rate of flow change is not faster than
what the units can respond to.
See HIGH WATER TEMPERATURE SWITCH OPEN.
1.
Check Temp HI Limit setting.
2.
Press CLEAR button and restart unit. If fault persists, contact
1.
qualified Service Personnel.
Replace 32 Pin Ribbon cable.
2.
Start the unit. The Air/Fuel Valve should rotate to the purge (open)
1.
position. If the valve does not rotate at all or does not rotate fully
open, check the Air/Fuel Valve calibration. If calibration is okay,
the problem may be in the Air-Fuel Valve or the Edge Controller.
Refer to qualified service personnel.
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