Lennox International Inc MERIT SERIES GAS FURNACE DOWNFLOW AIR DISCHARGE, ML193DF Control BOX

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ML193DF Parts Arrangement

CONTROL BOX
(Includes integrated control,
transformer and door switch)
	BAG ASSEMBLY
BLOWER MOTOR
(hidden)
BLOWER
ACCESS
PANEL
COMBUSTION
AIR INDUCER
		BLOWER DECK
	PRIMARY LIMIT
BURNER
ACCESS	COLD END HEADER BOX
PANEL	COLD END HEADER BOX
PANEL		HEAT EXCHANGER
		HEAT EXCHANGER
GAS VALVE
BURNER BOX ASSEMBLY
(includes sensor, rollout switches and ignitor)

FIGURE 1

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Image 3

Contents Table of Contents Installation Instructions ML193DFML193DF ML193DF Unit Dimensions − inches mmBlower Motor BAG AssemblyML193DF Parts Arrangement Control BOXShipping and Packing List Safety InformationDirect Vent Installation NON−DIRECT Vent ML193DF Gas FurnaceUse of Furnace as Construction Heater Combustion, Dilution & Ventilation Air GeneralEquipment in Confined Space − ALL AIR from Inside Equipment in Confined Space − ALL AIR from Outside Shipping Bolt RemovalInstallation − Setting Equipment Setting EquipmentFront Horizontal Back NC‡ NON−COMBUSTIBLE Floor Opening SizeCombustible Flooring Base Opening Size Side View− Seal the cabinet and check for air leaks Duct System Pipe & Fittings SpecificationsPiping and Fittings Specifications FiltersOutdoor Termination Kits Usage Schedule Joint Cementing ProcedureVenting Practices Piping Suspension GuidelinesVent Piping Guidelines Minimum Vent Pipe LengthsML193DF MIN. Vent Length Model Maximum Allowable Intake or Exhaust Vent Length in Feet Typical Exhaust Pipe Connections Typical Intake Pipe ConnectionsIntake Exhaust Typical AIR Intake Pipe Connections Inches 305mm or 12 in mm Inside Corner DetailUS Installations1 Canadian Installations2 − On field supplied terminations, a minimum distance Direct Vent Roof Termination KITFLUSH−MOUNT Side Wall Termination KIT 51W11 51mm 76mm Vent Pipe Support Reducer MAY beRequired to Adapt Unconditioned SpaceTop View Front ViewExhaust NON−DIRECT Vent Roof Termination KIT 203mm − 305mmML193DF NON−DIRECT Vent Application Using Existing Chimney To drain ML193DF with Evaporator CoilTrap / Drain Assembly Using 1/2 PVC or 3/4 PVC Furnace Isolate GAS Valve Gas PipingGAS Pipe Capacity − FT3/HR kL/HR Precautions and Procedures ElectricalElectrostatic Discharge ESD BOX Inside FACTORY− Installed Left Side MAKE−UPInterior MAKE−UP BOX Exterior MAKE−UP BOXThermostat Designations Typical ML193DF Field Wiring DiagramTypical ML193DF Wiring Diagram Automatic Hot Surface Ignition System For Your Safety Read Before OperatingUnit Start−Up Integrated ControlPage High Altitude Information Gas Pressure AdjustmentGAS Meter Clocking Chart Proper Combustion2286 − 3038m 2286m 3048m73W37 73W81 68W68 74W90 74W91 69W73 Other Unit Adjustments Heat FAN-OFF Time in SecondsNo Jumper High Low In. w.g Cfm Watts Cfm Watts cfm Watts Blower DataElectrical SHOCK, Fire Or Explosion Hazard ServicePage LED #1 Red LED #2 Green Planned ServiceIgnition Control Board Diagnostic Codes Diagnostic CodesTroubleshooting Heating Sequence of Operation Normal Heating Mode Abnormal Heating ModeHeating Sequence of Operation Heating Sequence Troubleshooting Cooling Sequence of Operation Normal Cooling Mode Abnormal Cooling ModeCooling Sequence of Operation Continuous Heat Speed FAN Sequence of Operation Troubleshooting Continuous Fan Sequence of OperationRepair Parts List Intake / Exhaust Pipe Start−Up & Performance Check ListGAS Supply Return AIR Duct System Supply AIR DuctVent Pipe Temperature RiseTotal External Static Drain Line Condensate Line ThermostatLY BELOW. Keep Clear of ALL OBSTRUC- Tions Requirements for Commonwealth of Massachusetts