Lochinvar 402 - 2072 Service Manual page 40

3
Troubleshooting
Table 3E (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Operator Interface
FAULT
Manual Reset
High Limit
(Will require a manual
reset once condition has
been corrected. Press
the RESET button on
the SMART SYSTEM
display to reset.)
Inlet Low
Sensor Open
(Will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
Sensor Shorted
(Will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
40
Copper-fin II/IIE Boiler and Water Heater
DESCRIPTION
The outlet water temperature has exceeded
the setting of the adjustable high limit.
The inlet water temperature did not exceed
130° within 15 minutes of ignition.
Either the inlet water, outlet water, system
supply, system return, or outdoor temperature
sensor has been disconnected.
Either the inlet water, outlet water, system
supply, system return, or outdoor temperature
sensor has been shorted.
CORRECTIVE ACTION
• Verify setting of adjustable high limit.
• Verify that the system is full of water and that all air
has been properly purged from the system.
• Verify that the appliance is piped properly into the
system. Refer to the Water Connections Section of
the Installation and
proper piping methods for the Copper-fin.
• Check 120 VAC to the pump motor on a call for heat.
If voltage is not present, check wiring leading to the
main control board. Replace the main control board if
necessary.
• If 120 VAC is present on a call for heat and the pump
is not operating, replace the pump.
• If the system pump is a variable speed pump, ensure
the system flow is not less than the boiler flow.
• Check temperature setting of the main control board.
• Check resistance of water sensors and compare to
the tables on page 35 of this manual. Replace the
sensor if necessary.
• Replace outlet sensor or high limit.
• Raise temperature setpoint above 130°.
• Install a 3-way valve or LTV valve per the piping
diagram in the Water Connections Section of the
Installation and Operation Manual.
• Replace the inlet sensor.
• Replace the main control board.
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
• Measure the resistance of the sensors and compare
the resistance to the tables on page 35 of this
manual.
• Replace the sensor if necessary.
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
• Measure the resistance of the sensors and compare
the resistance to the tables on page 35 of this
manual.
• Replace the sensor if necessary.
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