Lennox ML180UH135E60D

Page 1
UNIT INFORMATIONUNIT INFORMATION
Service Literature
©2016 Lennox Industries, Inc.
WARNING
Electric Shock Hazard. Can cause injury
or death. Unit must be properly grounded
in accordance with national and local
codes.
Line voltage is present at all components
when unit is not in operation on units
with single-pole contactors. Disconnect
all remote electric power supplies before
opening access panel. Unit may have
multiple power supplies.
CAUTION
As with any mechanical equipment, contact with
sharp sheet metal edges can result in personal
injury. Take care while handling this equipment and
wear gloves and protective clothing.
ML180UHE(X) series units are mid-e󰀩ciency gas furnac-
es used for upow or horizontal applications only, man-
ufactured with Lennox Duralok heat exchangers formed
of aluminized steel. ML180UHE(X) units are available in
heating capacities of 44,000 to 132,000 Btuh and cooling
applications 2 to 5 tons. Refer to Engineering Handbook
for proper sizing.
Units are factory equipped for use with natural gas. Kits
are available for conversion to LP/Propane operation.
ML180UHE(X) model units are equipped with a hot sur-
face ignition system. The ML180UHE(X) unit meets the
California Nitrogen Oxides (NOx) Standards and Califor-
nia Seasonal E󰀩ciency requirements.
All units use a redundant gas valve to assure safety shut-
o󰀨 as required by C.S.A. All specications in this manual
are subject to change. Procedures outlined in this manual
are presented as a recommendation only and do not su-
persede or replace local or state codes. In the absence
of local or state codes, the guidelines and procedures
outlined in this manual (except where noted) are recom-
mended only and do not constitute code.
WARNING
Improper installation, adjustment, alteration,
service or maintenance can cause property damage,
personal injury or loss of life. Installation and service
must be performed by a licensed professional HVAC
installer (or equivalent), service agency or the gas
supplier.
TABLE OF CONTENTS
Specications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2
Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4
Parts Identication . . . . . . . . . . . . . . . . . . . . . . . . . Page 6
I Unit Components . . . . . . . . . . . . . . . . . . . . . . . . Page 7
II Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 21
III Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 21
IV Heating System Service Checks . . . . . . . . . Page 21
V Typical Operating Characteristics . . . . . . . . . Page 26
VI Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . Page 26
VII Wiring and Sequence of Operation . . . . . . Page 29
ML180UHE(X)
Corp 1120-L4
Revised 10-2017
ML180UHE(X) SERIES UNITS

Lennox ML180UH135E60D Specifications

General

Model	ML180UH135E60D
Type	Gas Furnace
Efficiency Rating	80% AFUE
Heating Capacity	135, 000 BTU
Stages	Single Stage
Fuel Type	Natural Gas
Blower Motor Type	PSC
Stages of Heating	Single-Stage
Ignition Type	Hot Surface Ignition
Warranty	10 Years Limited

Summary

I-UNIT COMPONENTS

ELECTROSTATIC DISCHARGE (ESD) Precautions and Procedures

Precautions and procedures for handling electronic components to prevent ESD damage.

Combustion Air Inducer Pressure Switch (S18)

Troubleshooting

Procedures for troubleshooting the combustion air inducer pressure switch.

Blower Motor

Troubleshooting

Steps and procedures for troubleshooting the blower motor.

Replacing the Motor Module

Motor Module Installation

Instructions for installing a replacement motor control module.

II- PLACEMENT AND INSTALLATION

A- Heating Start-Up

Procedure for starting the furnace in heating mode.

B- Safety or Emergency Shutdown

Steps for safely shutting down the unit in an emergency.

C- Extended Period Shutdown

Instructions for shutting down the unit for extended periods.

D- Gas Pressure Adjustment

Gas Flow (Approximate)

Chart for measuring gas flow using a gas meter clocking.

E- Supply and Manifold Pressure

Procedures for measuring supply and manifold gas pressures.

F- Proper Combustion

Guidelines for checking and ensuring proper combustion analysis.

V-TYPICAL OPERATING CHARACTERISTICS

A-Blower Operation and Adjustment

General procedures for blower operation and speed adjustment.

B-Temperature Rise

Explanation of temperature rise factors and unit rating plate information.

C-External Static Pressure

Method for measuring external static pressure and adjusting blower speed.

VII- Wiring and Sequence of Operation

Schematic Wiring Diagram and Sequence of Operation

Detailed wiring diagram and step-by-step operational sequence for the furnace.