Langley/Empire DV-20E-5, DV-40E-5 Furnace Control Board Diagnostics, # of Blinks, Fault Condition

FURNACE CONTROL BOARD

DIAGNOSTICS

FAULT SEQUENCE CODE — TROUBLE SHOOTING GUIDE

# of Blinks		Fault Condition	Fault Correction
Steady On		Control OK
1	Flash	Temperature limit switch is open	-Check Circulating Air Blower Inlet or Grill Outlet for Blockage, Inducer
			Blower/Circulating Air Blower Run to Cool Heat Exchanger and Limit
			-Check for Flame Roll Out Condition Causing Roll Out Limit Switch on
			Burner Box to Open
			-Clean Circulating Air Filter
2	Flashes	Pressure switch is open with inducer on	-Check Heat Exchanger and Flue System, Outlet and Inlet for Restriction
			-Check Inducer Blower/Wheel for Operation/Airflow
			-Check Pressure Switch
3	Flashes	Pressure switch is closed with inducer off	-Check Pressure Switch and Replace
4	Flashes	Lockout due to failed ignition	-Check for Broken Ignitor
			-Check for Bent Ignitor Bracket - Ignitor too far from Burner
			-Check for Flame Sensor Malfunction/or False Ground
			-Check Gas Valve
			-Reset Thermostat
5	flashes	L1/Neutral reversed or voltage not present	-Shut Off Power to Unit and Dis-Connect Cordset Plug from Wall Recep-
		on L1	tacle.
			Open Junction Box and Un-Reverse Polarity of Incoming Power Leads
Rapid Flash		Flame sense or internal control fault	-Check Ignitor Operation
			-Check Flame Sensor for Malfunction or False Grounding
			-Check Gas Valve
			-Reset Thermostat

Note: If the hot surface ignitor is to be replaced, be sure to disconnect all power to the unit. Be very careful in handling the new ignitor as they are fragile and can be broken easily if hit or dropped.

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