Lochinvar FTxl 500 Service Manual page 43

3
Troubleshooting
Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
Flame Sequence
(will require a manual
reset once the condition
The flame detector circuit is seeing a flame
has been corrected.
signal while the gas valve is off.
Press the RESET button
on the SMART SYSTEM
display to reset.)
The outlet water temperature has exceeded
Outlet ARHL
the setting of the automatic reset high limit.
Outlet MRHL
(will require a manual
reset once the condition
The outlet water temperature has exceeded
has been corrected.
the setting of the manual reset high limit.
Press the RESET button
on the SMART SYSTEM
display to reset.)
(continued)
DESCRIPTION
Service Manual
CORRECTIVE ACTION
• Check supply voltage for proper polarity.
• Check external wiring for voltage feedback.
• Check the flame rod and make sure it is clean.
• Check the internal wiring for bad connections.
• Replace main control board.
• Adjust the set point of the auto reset limit to a higher
setting up to a maximum of 200°F. Reference the
FTXL Installation and
adjusting procedures.
• Verify that the system is full of water and that all air
has been properly purged from the system.
• Verify that the boiler is piped properly into the heating
system. Refer to Section 6 - Hydronic Piping of the
FTXL Installation and
for the proper piping methods for the FTXL boiler.
• Check 120 vac to boiler pump motor on a call for
heat. If voltage is not present, check wiring back to
the main control board.
• If 120 vac is present on a call for heat and the boiler
pump is not operating, replace the pump.
• If the system pump is a variable speed pump, ensure
that the system flow is not less than the boiler flow.
• If operating on something other than an outlet sensor,
check temperature setting of the main control board.
• Check resistance of water sensors and compare to
Table 3-2A on page 39 of this manual.
sensor if necessary.
• Replace the main control board if necessary.
• Adjust the set point of the manual reset limit to a higher
setting up to a maximum of 210°F. Reference the
FTXL Installation and
adjusting procedures.
• Verify that the system is full of water and that all air
has been properly purged from the system.
• Verify that the boiler is piped properly into the heating
system. Refer to Section 6 - Hydronic Piping of the
FTXL Installation and
for the proper piping methods for the FTXL boiler.
• Check 120 vac to boiler pump motor on a call for
heat. If voltage is not present, check wiring back to
the main control board.
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