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12
Troubleshooting
Table 12E Troubleshooting Chart - Fault Messages Displayed on Water Heater Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
Flame
Sequence
(will require a manual
reset once the condition
has been corrected.
Press the RESET button
on the display to reset.)
The flame detector circuit is seeing a flame
signal while no flame is present.
• Check supply voltage for proper polarity.
• Check external wiring for voltage feedback.
• Check the flame rod and make sure it is clean.
• Check the internal wiring for bad connections.
• Replace main control board.
No Flame Ign
(will require a manual
reset once the condition
has been corrected.
Press the RESET button
on the display to reset.)
The unit has failed to prove main burner
ignition after four (4) attempts.
• Ensure gas valve switch is ON (Models SNR150-100
and
SNA285-125).
• Check wiring harness connection at the gas valve and
at the main control board.
• Inspect spark electrode and associated wiring for
damage and connection. Reference page 60 of this
manual for removal and cleaning procedures.
Replace if necessary.
• Check for proper electrical grounding of the 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 6 - 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 correctly
installed and that there are no obstructions.
• Check for 24 VAC to the gas valve at the 2-pin
connection on the side of the main control board
during the ignition attempt. If no voltage is present,
replace the main control board.
• If 24 VAC is present at the main control board, check
the wiring between the main control board and the
gas valve. Replace the wiring if necessary.
• 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 60 of this manual for removal and
cleaning procedures. Replace if necessary.
• Inspect the burner. Reference page 60 of this manual
for removal and cleaning procedures. Replace if
necessary.
• Replace the main control board.
Installation & Service Manual
TM
