Table 3E - Troubleshooting Chart - Fault Messages - Lochinvar 402 Service Manual

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Troubleshooting
Table 3E Troubleshooting Chart - Fault Messages Displayed on Operator Interface
FAULT
Gas Pressure SW
(Will require a manual
reset once the condition
has been corrected.)
Flow Switch/
LWCO
(Lockout will reset
automatically after
5 minutes or may be
reset immediately once
condition has been
corrected. Press the
RESET button on the
SMART SYSTEM display
to reset.)
Flame Sequence
(Will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
Anti-cycling
Copper-fin II/IIE Boiler and Water Heater
(continued)
DESCRIPTION
- Either the optional manual reset low gas
pressure switch or the optional manual reset
high gas pressure switch tripped.
- Models 992 - 2072 (natural gas) - Automatic
Reset Low Gas is open.
Either the flow switch or the optional low
water cutoff is not making.
The flame detector circuit is seeing a flame
signal while the gas valve is de-energized.
The main control board has received a call
for heat too quickly after the previous call for
heat has ended.
CORRECTIVE ACTION
• Reset the pressure switches.
• Measure the supply gas pressure to determine
cause of failure. Refer to the Gas Connections
Section of the Installation and Operation Manual for
detailed information concerning the gas supply.
• Correct the supply gas pressure if necessary.
• Check pump operation on a call for heat.
• Check for closed valves or obstructions in the
water piping.
• Verify system is full of water and all air has been
purged from the system.
• Check supply voltage for proper polarity.
• Check that the gas valve is closed.
• Check external wiring for voltage feedback.
• Check the internal wiring for bad connections.
• Replace main control board.
• The control board will release the call for heat after
a set time period.
• The control board will release the call for heat if the
outlet temperature drops too quickly.
Service Manual
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