Lochinvar Crest w/RealTime O2 Trim 100 Series Service Manual page 46

3
Troubleshooting
Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
The main control board has received a call
for heat too quickly after the previous call for
Anti-cycling
heat has ended.
The unit has failed to prove main burner
ignition. It will require a manual reset before
attempting to fire again.
Flame Failure
(will require a manual
reset once the condition
has been corrected.
Press the RESET button
on the SMART TOUCH
display to reset.)
46
DESCRIPTION CORRECTIVE ACTION
• The control board will release the call for heat after a
set time period.
• The control board will release the call for heat if the
outlet temperature drops too quickly.
• Inspect spark electrode and associated wiring for
damage and connection. Reference this manual for
removal and cleaning procedures.
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.
pressures should be between 4 inches w.c. (1.0 kPa)
and 14 inches w.c. and LP gas pressures should be
between 8 inches w.c. (1.99 kPa) and 14 inches w.c.
(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 vent/air intake pipes are correctly
installed and that there are no obstructions.
• If 120 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.
disconnect the wiring from the gas valve and attempt to
measure voltage at that point. The main control board
can detect if the gas valve is not connected and will
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.
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 sensors and associated wiring. Reference
this manual for removal and cleaning procedures.
Replace if necessary.
• Inspect the burner. Reference this manual for removal
and cleaning procedures. Replace if necessary.
• Check/replace filter.
Service Manual
Replace if
Natural gas
Do not
When the valve is