Lennox International Inc G24-200 POWER ON THERMOSTAT CALLS FOR HEAT W1 ENERGIZED

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Manual background

HEATING SEQUENCE OF OPERATION WITH SINGLE-STAGE THERMOSTAT

NOTE − THIS FURNACE FUNCTIONS WITH TWO INDEPENDENTLY CONTROLLED HEAT SECTIONS. THE GRAY BOXES INDICATE COMPONENTS WHICH EFFECT BOTH HEAT SECTIONS SIMULTANEOUSLY.

NORMAL HEATING MODE

POWER ON

THERMOSTAT CALLS FOR HEAT

(W1 ENERGIZED)

K13 AND K19 RELAY ENERIZED.

(W1 AND W2 OF FURNACE

TERMINAL STRIP JUMPERED.)

A3 (A12) IGNITION CONTROL LED ON.

IS THE S10 (S99) HIGH LIMIT CLOSED?

YES

IS THE S47 (S69) ROLLOUT SWITCH CLOSED?

YES

IS THE B6 (B15) COMBUSTION

AIR BLOWER ON?

YES

ABNORMAL HEATING MODE

	NO		DETERMINE WHY AUTOMATIC-RESET
			S10 (S99) HIGH LIMIT OPEN.

	NO		CHECK VENTING SYSTEM
			OPERATION/BLOCKAGE BEFORE
			OPERATION/BLOCKAGE BEFORE
			RESETTING THE MANUALLY-RESET S47
			(S69) ROLLOUT SWITCH.


	NO		CHECK K13−1 CONTACT OPERATION AND
			WIRING TO B6 (B15) COMBUSTION AIR
			WIRING TO B6 (B15) COMBUSTION AIR
			BLOWER?

IS THE S18 (S45) COMBUSTION AIR BLOWER PROVING SWITCH CLOSED?

YES

B6 (B15) COMBUSTION AIR BLOWER

PREPURGE FOR 30 SECS.

8 SEC TRIAL FOR IGNITION − START IGNITION TRAIL, GV1 (GV3) GAS VALVE OPENS ON LOW HEAT AND AFTER A 3 SEC. DELAY OPENS ON HIGH HEAT. IS FLAME SENSED WITHIN 8 SECS?

YES

K56 (K57) RELAY ENERGIZED. K25 CIRCUIT BOARD ENERGIZED. SYSTEM BLOWERS ON AFTER 45 SEC DELAY.

YES

FLAME SENSE OK?

	NO	CHECK SENSING TUBE FOR BLOCKAGE
	NO	AND S18 (S45) SWITCH FOR PROPER


		OPERATION.

			NO

	GV1 (GV3) GAS VALVE CLOSED, SPARK
NO	OFF. INCREMENT TRAIL REGISTER.
	(DURING RETRY PERIOD LED FLASHES
	(DURING RETRY PERIOD LED FLASHES
	.5 SEC. ON AND 2.5 SEC. OFF. ARE THE
	THREE TRIALS COMPLETE?


	YES

LOCKOUT OCCURS. TO RESET A3 (A12) IGNITION CONTROL MOVE THERMOSTAT SWITCH FROM HEAT TO OFF TO HEAT.

NO

CHECK BELT.

CHECK RELAYS.

NO

YES

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Contents P504613M INSTALLATION INSTRUCTIONS G24-2002P0805 WHAT TO DO IF YOU SMELL GASG24−200 Unit Dimensions − inches mm PageBACK VIEW G24−200 Filter Box Dimensions − inches mmSIDE VIEW TOP VIEWG24−200 Parts Arrangement G24−200 HEAT SECTION AND CABINETPage G24−200 Parts Arrangement Continued G24−200 BLOWER SECTIONPage Safety G24−200 Gas FurnaceShipping and Packing List setting General Combustion, Dilution & Ventilation AirCements and glues EQUIPMENT IN CONFINED SPACE ALL AIR FROM INSIDE Setting Equipment Return Air Plenum / Filter Box InstallationBOTTOM RETURN AIR FILTER BOX INSTALLATION PageBlower Motor / Drive Installation Duct SystemVenting Venting Using a Masonry Chimney Page Page SERVING A SINGLE CATEGORY I APPLIANCE PageSERVING A SINGLE CATEGORY I APPLIANCE PageSERVING TWO OR MORE CATEGORY I APPLIANCES VENT CONNECTOR CAPACITYSERVING TWO OR MORE CATEGORY I APPLIANCES COMMON VENT CAPACITYPage CARBON MONOXIDE POISONING HAZARD FOR INSTALLATIONS IN THE USA AND CANADA VENT TERMINATION CLEARANCESPage Horizontal Venting Gas Piping FIRE OR EXPLOSION HAZARD Electrical box right side G24−200 FIELD WIRING DIAGRAM 120V SINGLE PH 60HZAlternate make-up Alternate make-upG24-200FIELD WIRING DIAGRAM J UNITS − 575V 3PH 60HZ G24−200 FIELD WIRING DIAGRAMG UNITS − 460V 3PH 60HZ Alternate make-upFIGURE Page Y UNITS − 208/230V 3PH 60HZ WIRING SCHEMATIC DIAGRAM FOR G24−200P UNITS − 208/230V 1PH 60 HZ G UNITS − 460V 3PH 60HZUnit Start−Up Heating Sequence of Operation Gas Pressure Adjustment Other Unit Adjustments and OperationHigh Altitude Information Temperature Rise Setting blower CFM TABLE ACCESSORY AIR RESISTANCE TABLE DRIVE KIT SPECIFICATIONSPage Repair Parts List G24−200 Start−up and Performance Check ListABNORMAL HEATING MODE TroubleshootingNORMAL HEATING MODE PageABNORMAL HEATING MODE 3 − OFF NO POWER OR DETECTED FAULTNORMAL HEATING MODE LED CODESPOWER ON THERMOSTAT CALLS FOR HEAT W1 ENERGIZED IS THE S10 S99 HIGH LIMIT CLOSED? YES FOR A SINGLE CONDENSING UNIT COOLING SEQUENCE OF OPERATIONFOR TWO CONDENSING UNITS MANUAL FAN OPERATION