Lochinvar CREST 3 - Manual (Page 44)

3
Troubleshooting
Service Manual
44
Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT DESCRIPTION CORRECTIVE ACTION
Auto Reset
High Limit
The outlet water temperature has exceeded
the setting of the automatic reset high limit.
• 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 5 - Hydronic Piping of the
Crest Installation and Operation Manual
for the proper piping methods for the Crest 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.
• Check the ARHL set point.
• 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.
• If the optional manual reset high limit has tripped,
check setting of the device.
• Check resistance of water sensors and compare to
Table 3B on page 38 of this manual. Replace
sensor if necessary.
• Replace the main control board.
Manual Reset
High Limit Open
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
SMART TOUCH
display
to reset.)
The outlet water temperature has exceeded
the setting of the high limit.
• 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 5 - Hydronic Piping of the
Crest Installation and Operation Manual
for the proper piping methods for the Crest boiler.
• Check voltage to boiler pump motor on a call for
heat. If voltage is not present, check wiring back to
the main control board.
• Replace the pump relay if necessary.
• 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 either an inlet or system supply sensor,
check temperature setting of the main control board.
• If the high limit has tripped, check setting of the
device and the MRHL set point.
• Check resistance of water sensors and compare to
Table 3B on page 38 of this manual. Replace
sensor if necessary.
• Replace high limit (if equipped).
• Replace main control board.