Lochinvar 3.5, 1.5, 2.5 Troubleshooting continued, Fault, Description, Corrective Action

Service Manual

3 Troubleshooting (continued)

Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface

FAULT	DESCRIPTION	CORRECTIVE ACTION
	The main control board has received a call	• The control board will release the call for heat after a
Anti-cycling	for heat too quickly after the previous call for	set time period.
	heat has ended.	• The control board will release the call for heat if the
		outlet temperature drops too quickly.
	The unit has failed to prove main burner	• Inspect spark electrode and associated wiring for
	ignition. It will require a manual reset before	damage and connection. Reference page 34 of this
	attempting to fire again.	manual for removal and cleaning procedures.
		Replace if necessary.
		• Visually check for presence of a spark from the view
		port.
		• Check for proper electrical grounding of the unit.
		• Check incoming supply gas pressure. Natural and
		LP gas pressures should be between 4 - 14 inches w.c.
		(1.0 - 3.5 kPa). Refer to Section 6 - Gas Connections
		of the Crest Installation and Operation Manual for
		detailed information concerning the gas supply.
		• Verify that the plastic hose from gas valve 1 to the air
		inlet is connected and is not damaged.
		• Verify that the vent/air intake pipes are correctly
Flame Failure		installed and that there are no obstructions.
Ignition		• If 120 vac is present at the main control board, check
(will require a manual
		the wiring between the main control board and the gas
reset once the condition		valve. Replace the wiring if necessary. Do not
has been corrected.		disconnect the wiring from the gas valve and attempt to
Press the RESET button		measure voltage at that point. The main control board
on the SMART TOUCH		can detect if the gas valve is not connected and will
display to reset.)		display the Gas Valve / Connection fault.
		• If 120 vac is present, check the outlet of the valve to
		ensure the valve is flowing gas. With a manometer
		connected to the outlet tap of the gas valve, when the
		unit is in the prepurge period, there should be a
		negative pressure present. When the valve is
		energized a change in pressure should occur. If the
		pressure change does not occur, the gas valve is not
		opening. Replace the gas valve.
		• Inspect flame sensor and associated wiring.
		Reference page 34 of this manual for removal and
		cleaning procedures. Replace if necessary.
		• Inspect the burner. Reference page 34 of this manual
		for removal and cleaning procedures. Replace if
		necessary.

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