3 Troubleshooting
46
Service Manual
Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT DESCRIPTION CORRECTIVE ACTION
Fan Speed High
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
SMART TOUCH
display
to reset.)
The actual fan RPM is 30% higher than what
is being called for.
• Vent/air intake lengths exceed the maximum allowed
lengths. Refer to Section 2 - General Venting of the
Crest Installation and Operation Manual for
proper lengths.
• Check for obstruction or blockage in the vent/air
intake pipes or at terminations.
• Check the wiring connections at the fan and at the
main control board.
• Replace the fan.
Louver Proving
Sw Open
An optional remote proving switch is not
making.
• Check function of remote devices.
• Check for loose or misplaced jumper if proving switch
is not installed.
Flue Temp High
The stack temperature has exceeded the set
parameters for the boiler.
• Inspect the heat exchanger. Reference page 35 of
this manual for the procedure on how to clean the flue
side of the heat exchanger.
• Inspect the flue sensor and associated wiring.
Measure the resistance of the flue sensor and
compare to Table 3E on page 39 of this manual.
Replace the sensor if necessary.
• Verify that the vent/air intake pipes are properly
installed and that there are no obstructions.
Delta T High
The temperature rise across the heat
exchanger has exceeded the set parameters
for the boiler.
• 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 for 120 vac to the boiler pump motor on a call
for heat. If voltage is not present, check the wiring
back to the main control board. Replace the main
control board if necessary.
• If 120 vac is present on a call for heat and the boiler
pump is not operating, replace the pump.
• Verify that the boiler pump is set to the proper speed
or that the pump is the proper size. Reference
Section 5 - Hydronic Piping of the Crest
Installation and Operation Manual for boiler
pump specifications.
• Inspect the inlet and outlet sensors and associated
wiring. Measure the resistance of the sensors and
compare to the tables on page 39 of this manual.
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