29
10 Troubleshooting
Table 10A Troubleshooting Chart - No Display
FAULT CAUSE CORRECTIVE ACTION
No Display
No 120 VAC supplied to the unit
- Check external line switch, fuse, or breaker.
- Ensure On/Off switch is in the ON position.
- Check 120 VAC through the On/Off switch.
- Check wiring harness connection between external
power and control module.
No voltage through the switch - Replace switch.
Bad control module - Replace control module.
Low Outlet
Water Temp
Modulating valve lost calibration
- Remove cover on modulating valve electronics and
press the recessed calibration button to re-calibrate
the valve.
Boiler water supply temperature or flow
has dropped below requirement to satisfy
demand
- Ensure ball valves are open fully.
- Ensure boiler water flow matches what is specified in
the sizing table.
- Ensure boiler side Y strainers are not clogged.
Control module not supplying 0 - 10 VDC
control signal to valve
- Ensure the valve is wired correctly by referencing the
wiring diagram on page 32 of this manual.
Modulating valve is not in AUTO Mode - Rotate valve handle until it is in AUTO Mode.
No 24 VAC power supplied to modulating
valve
- Ensure the valve is wired correctly by referencing the
wiring diagram on page 32 of this manual.
- Ensure the transformer is connected to the harness
correctly and its built-in circuit breaker has not tripped.
Heat exchanger is improperly sized for load
- Reduce load on heat exchanger or re-size heat
exchanger.
Heat exchanger scaled on boiler side - Clean and de-scale heat exchanger.
High limit is tripped
- Ensure high limit is set correctly so that power to the
valve will be restored when the temperature returns to
a low enough value.
High Outlet
Water Temp
Modulating valve is not in AUTO Mode - Rotate valve handle until it is in AUTO Mode.
Modulating valve lost calibration
- Remove cover on modulating valve electronics and
press the recessed calibration button to re-calibrate
the valve.
Heat exchanger scaled on DHW side - Clean and de-scale heat exchanger.
Temperature
Swings
Outside
Specified
Range
Pump not functioning
- Ensure pump is wired correctly by referring to the
wiring diagram on page 32 of this manual.
- Replace pump if faulty.
RTD or RTD harness not connected or
malfunctioning
- Ensure harness is connected and wired correctly
by referring to the wiring diagram on page 32 of this
manual.
- Check RTD resistance by using the chart on page 30
to ensure RTD is functional.
- Replace RTD or harness if faulty.
"S.Br"
Displayed
RTD or RTD harness not connected or
malfunctioning
- Ensure harness is connected and wired correctly
by referring to the wiring diagram on page 32 of this
manual.
- Check RTD resistance by using the chart on page 30
to ensure RTD is functional.
- Replace RTD or harness if faulty.
Indirect Plate Water Heater Installation & Service Manual
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