Lenox Installation Guidelines for Lennox ML180UHE Gas Furnace

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Setting Equipment

WARNING

Do not install the furnace on its front or its back. Do not connect the return air ducts to the back of the fur- nace. Doing so will adversely affect the operation of the safety control devices, which could result in per- sonal injury or death.

The ML180UHE gas furnace can be installed as shipped in either the upflow position or the horizontal position. Select a location that allows for the required clearances that are listed on the unit nameplate. Also consider gas supply connections, electrical supply, vent connection, and installation and service clearances [24 inches (610

mm)at unit front]. The unit must be level.

NOTE − Units with 1/2 or 3/4 hp blower motors are equipped with three flexible legs and one rigid leg. See figure 7. The rigid leg is equipped with a shipping bolt and a flat white plastic washer (rather than the rubber mounting grommet used with a flexible mounting leg). The bolt and washer must be removed before the furnace is placed into op- eration. After the bolt and washer have been removed, the rigid leg will not touch the blower housing.

Units with 1/2 or 3/4 HP Blower Motor

RIGID LEG

remove shipping bolt and washer

FIGURE 7

Upflow Applications

Allow for clearances to combustible materials as indicated on the unit nameplate. Minimum clearances for closet or al- cove installations are shown in figure 8.

Upflow Application Installation Clearances

 

Top

 

Left Side

 

Right Side

 

Bottom

 

Type of Vent

Type C

Type B1

Connector

 

 

Top

1 in. (25 mm)

1 in. (25 mm)

*Front

2−1/4 in. (57 mm)**

2−1/4 in. (57 mm)

 

 

 

Back

0

0

 

 

 

Sides

0†

0

 

 

 

Vent

6 in. (152 mm)

1 in. (25 mm)

 

 

 

Floor

0‡

0‡

*Front clearance in alcove installation must be 24 in. (610 mm). Maintain a minimum of 24 in. (610 mm) for front service access. ** 4−1/2" if single wall vent pipe is used.

‡For installation on a combustible floor, do not install the furnace directly on carpeting, tile or other combustible materials other than wood flooring.

†Left side requires 3 inches if a single wall vent is used on 14−1/2 inch cabinets, or 2 inches if a single wall vent pipe is used on 17−1/2 inch cabinets.

FIGURE 8

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Contents Table of Contents Installation Instructions ML180UHETOP View Unit Dimensions − inches mmMake−Up Box Heat Exchanger Combustion Air Inducer Parts ArrangementBurner Box Gas ValveSafety Information ML180UHE Gas FurnaceShipping and Packing List General Use of Furnace as Construction Heater Combustion, Dilution & Ventilation Air Equipment in Confined Space ALL AIR from Inside Equipment in Confined Space Setting Equipment Return Air Right Horizontal Application Installation Clearances Top LeftEnd Bottom Typical Horizontal ApplicationDuct System FiltersUpflow Position VentingTop Vent Discharge Left Side Vent DischargeHorizontal Left Position Horizontal Left Position Horizontal Right PositionSide Vent Discharge Side Vent Discharge − no modifications necessaryVent Connection Upflow and Horizontal Position Common Venting Using Metal−Lined Masonry Chimney −1/2 18 − The common vent diameter must always be at least as Cated or common venting system, you must inspectFeet FAN + FAN FAN + NAT 130 Carbon Monoxide Poisoning Hazard − In some localities, codes may require the installation Ers or straps. Install a drip leg in vertical pipe runs toGas Piping Gas supply piping should not allow more than 0.5W.C. dropHorizontal Application Left−Side Air DischargeRight−Side Air Discharge Interior MAKE−UP BOX Installation ElectricalElectrostatic Discharge ESD Thermostat Designations ML180UHE Schematic Wiring Diagram and Sequence of Operation Integrated Control Typical ML180UHE Field Wiring DiagramUnit Start−Up For Your Safety Read Before LightingGAS Meter Clocking Chart Gas Pressure AdjustmentProper Combustion High AltitudeManifold Pressure Settings at all Altitudes Other Unit AdjustmentsNo Jumper Heat FAN-OFF Time in Seconds995 1380975 115 945 1345Order to maintain proper air velocity Single Side Return Air − Air volumes in bold require field640 1940 420 1750 310 230Electrical SHOCK, Fire Or Explosion Hazard ServiceHeat Exchanger Removal ML180UHE BURNER, Combustion AIR Inducer Assembly−090, −110 −135 units −045 and −070 unitsRepair Parts List Planned ServiceRED LED Integrated Control Diagnostic CodesHeating Sequence of Operation Normal Heating Mode Abnormal Heating ModeHeating Sequence Cooling Sequence of Operation Normal Cooling Mode Abnormal Cooling ModeContinuous FAN Sequence of Operation Start−Up & Performance Check List Temperature Rise Cooling ModeUnit Operation Drain Line