Lochinvar SNA500-125 Troubleshooting continued, Fault, Description, Corrective Action, Fan High

TM

Installation & Service Manual

13 Troubleshooting (continued)

Table 13E (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Water Heater Interface

FAULT	DESCRIPTION	CORRECTIVE ACTION
	The actual fan RPM is 30% higher than	• Vent/air intake lengths exceed the maximum allowed
	what is being called for.	lengths. Refer to Section 2 - General Venting for
Fan High		proper lengths.
OR		• Check for obstruction or blockage in the vent/air
Fan Speed High		intake pipes or at terminations.
(will require a manual		• Check the wiring connections at the fan and at the
reset once the condition
		main control board.
has been corrected. Press
the RESET button on the		• Replace the fan.
display to reset.)		• Replace the main control board.
Sensor Open	Either the heat exchanger inlet water, heat	• Check the sensors and their associated wiring.
(will require a manual	exchanger outlet water or tank temperature	Repair or replace the sensor or wiring if damaged.
reset once the condition	sensor has been disconnected.	• Measure the resistance of the sensors and compare
has been corrected. Press
	S1 = Outlet Sensor	the resistance to the tables on page 60 of this
the RESET button on the
		manual.
display to reset.)	S2 = Inlet Sensor
		• Replace the sensor if necessary.
Sensor Shorted	Either the heat exchanger inlet water heat	• Check the sensors and their associated wiring.
(will require a manual	exchanger outlet water or tank temperature	Repair or replace the sensor or wiring if damaged.
	sensor has been shorted.
reset once the condition		• Measure the resistance of the sensors and compare
has been corrected. Press	S1 = Outlet Sensor	the resistance to the tables on page 60 of this
the RESET button on the	S2 = Inlet Sensor	manual.
display to reset.)		• Replace the sensor if necessary.
External Limit	An optional remote limit switch is not	• Check function of remote devices.
Switch	making.	• Check for loose or misplaced jumper if external
(will retry after 5
		limit switch is not installed.
minutes. RESET may be
pressed after condition is
corrected.)
	The flue temperature has exceeded the set	• Inspect the heat exchanger. Reference page 57 of
	parameters for the water heater.	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
Temp O/Shoot		compare to Table 13C on page 60 of this manual.
		Replace the sensor if necessary.
		• Verify that the vent/air intake pipes are properly
		installed and that there are no obstructions.
		• Replace the main control board.
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