Lochinvar 151 - 801 Sensor Shorted, Louver Proving, Flue Temp High, Delta T High, Fault

Service Manual

3Troubleshooting (continued)

Table 3F (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Water Heater Interface

FAULT	DESCRIPTION	CORRECTIVE ACTION
Sensor Shorted	Either the inlet water or outlet water	• Check the sensors and their associated wiring.
(will require a manual	temperature sensor has been shorted.	Repair or replace the sensor or wiring if damaged.
reset once the condition
has been corrected. Press		• Measure the resistance of the sensors and compare
the RESET button on the		the resistance to the tables on page 26 of this
SMART SYSTEM display		manual.
to reset.)		• Replace the sensor if necessary.
Louver Proving	An optional remote proving switch is not	• Check function of remote devices.
(will require a manual	making.	• Check for loose or misplaced jumper if auxiliary
reset once the condition
has been corrected. Press		proving switch is not installed.
the RESET button on the
SMART SYSTEM display
to reset.)
	The stack temperature has exceeded the set	• Inspect the heat exchanger. Reference page 23 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
		compare to Table 3D on page 26 of this manual.
Flue Temp High		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.
	Scaling has reduced water flow.	• Deliming may be required.
		• Verify that the system is full of water and that all air
		has been properly purged from the system.
		• Verify that the water heater is piped properly into the
		heating system. Refer to Section 6 - System Piping
		of the Armor Water Heater Installation and Operation
		Manual for the proper piping methods for the Armor
		water heater.
		• Check for 120 VAC to the water heater pump motor on
Delta T High	The temperature rise across the heat	a call for heat. If voltage is not present, check the
	exchanger has exceeded the set parameters	wiring back to the main control board. Replace the
	for the water heater.	main control board if necessary.
		• If 120 VAC is present on a call for heat and the water
		heater pump is not operating, replace the pump.
		• Verify that the water heater pump is set to the proper
		speed or that the pump is the proper size. Reference
		Section 6 - System Piping of the Armor Water Heater
		Installation and Operation Manual for water heater
		pump specifications.

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