Lochinvar SNR150-100 Troubleshooting continued, Fault, Description, Corrective Action, No Flame

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
					• Inspect spark electrode and associated wiring for
					damage and connection. Reference page 56 of this
					manual for removal and cleaning procedures.
					Replace if necessary.
					• Check for proper electrical grounding of unit.
					• Check incoming supply gas pressure. Natural gas
					pressures should be between 4 - 14 inches w.c. and
					LP gas pressures should be between 8 - 14
					inches w.c. Refer to Section 7 - Gas Connections for
					detailed information concerning the gas supply.
					• Verify that the plastic hose from the gas valve to the air
					inlet is connected and is not damaged.
					• Verify that the vent/air intake pipes are installed
					correctly and there are no obstructions.
					• Check for 24 VAC to the gas valve at the 2-pin
No Flame					connection on the side of the main control board
					during the ignition attempt. If no voltage is present,
Running					replace the main control board.
(will require a manual	The unit	was	running	and lost the flame	• If 24 VAC is present at the main control board, check
reset once the
condition has been	signal.	This	condition	occurred four (4)	the wiring between the main control board and the gas
					valve. Replace the wiring if necessary. Do not
corrected. Press the	straight times.
					disconnect the wiring from the gas valve and attempt
RESET button on the
					to measure voltage at that point. The main control
display to reset.)
					board can detect if the gas valve is not connected and
					will display the GV / Relay Fail fault.
					• If 24 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 56 of this manual for removal and
					cleaning procedures. Replace if necessary.
					• Inspect the burner. Reference page 56 of this manual
					for removal and cleaning procedures. Replace if
					necessary.
					• Replace the main control board.
GV/Relay					• Ensure gas valve switch is ON (Models SNR150-100
					and SNA285-125).
Fail
(will require a manual					• Check wiring harness connection at the gas valve and
reset once the	The main control board did not detect the				at the main control board.
condition has been	gas valve.				• Replace the gas valve wire harness.
corrected. Press the
RESET button on the					• Replace the gas valve.
display to reset.)					• Replace the main control board.
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