Emerson 50A55 Integrated Furnace, Troubleshooting, Control Module, Guide, Chart, 4A4E, 4G YES

INTEGRATED FURNACE	TROUBLESHOOTING
CONTROL MODULE	GUIDE

CHART 4

4A4E

Main Burner

Ignition Check.

Inducer ON.

Does ignitor	YES
warm up and
glow?

NO

4B

Turn power OFF to furnace.

Unplug ignitor from wire

harness. Connect voltmeter

across ignitor wiring harness leads from control. Energize system.

Does burner	YES
ignite?

NO

4F

Is gas

valve manual NO knob in ON position?

4G YES

Turn manual knob to OFF position. Connect manometer to outlet pressure tap. Turn knob to ON position. Energize system.

Turn manual knob

to ON position.

Check operation.

Purge system of

air. Energize

system. Check

operation.

		4C	4H		4I
			Is outlet
					Refer to service
Replace ignitor.		Is 120V	pressure
	YES			YES	facts or installer’s
		present at	detected after
Check operation.					guide for proper
		ignitor leads?	ignitor warm-
					pressure settings.
			up time?
		NO	NO

4J YES

Is manifold

pressure

adjusted to

required setting?

NO

4K

Is gas at source?

Adjust manifold

to required

NOpressure setting.

Check operation.

4D4L

YES

Replace broken or		Is 120V
	YES	present at
defective wiring.		control terminals
Check operation.		IGN & IGN
		NEUTRAL?
		NO

Connect voltmeter

to gas valve

leads. Energize

system.

4M

Is 24V

detected

across gas

valve leads after

ignitor warm-

up time?

			Restore gas
			supply at source.
			Check operation.
	4N
	Is 24V
	present		Replace control
NO	across control	NO
	MV terminals after		module. Check
	ignitor warm-		operation.
	up time?

	YES
Replace control.	Replace gas
	valve. Energize
Check operation.	system. Check
	operation.

YES

Repair or

replace broken

leads to gas valve.

Check operation.

TECHNICAL HELP

!WARNING

If diagnostic indicator (LED)

shows continuous flashing, turn off gas supply at source before disconnecting electrical power!

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