Lennox ML180DFE Series Unit Information

S e r v i c e L i t e r a t u r e
ML180DFE series units are mid-efficiency gas furnaces
used for downflow applications only, manufactured with
Lennox Duralok heat exchangers formed of aluminized
steel. ML180DFE units are available in heating capacities
of 44,000 to 110,000 Btuh and cooling applications 1.5 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.
ML180DFE model units are equipped with a hot surface
ignition system and a constant torque ECM motor. The
motor is programmed to provide constant torque at each
of the five selectable speed taps. All units use a redundant
gas valve to assure safety shut-off as required by C.S.A.
All specifications in this manual are subject to change.
Procedures outlined in this manual are presented as a
recommendation only and do not supersede or replace lo-
cal or state codes. In the absence of local or state codes,
the guidelines and procedures outlined in this manual
(except where noted) are recommended only and do not
constitute code.
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.

TABLE OF CONTENTS

Specification ..........................................................Page 2
Blower Data............................................................Page 3
Parts Identification .................................................Page 5
I Unit Components ................................................Page 6
II Installation.........................................................Page 19
III Start Up............................................................Page 19
IV Heating System Service Checks ..................Page 19
V Typical Operating Characteristics ..................Page 22
VI Maintenance....................................................Page 23
VII Wiring and Sequence of Operation................Page 27
UNIT INFORMATION UNIT INFORMATION
Corp 1121-L4
Revised 04/2022
ML180DFE SERIES UNITS
Page 1
WARNING
Electric shock hazard. Can cause injury
or death. Before attempting to perform
any service or maintenance, turn the
electrical power to unit OFF at disconnect
switch(es). Unit may have multiple power
supplies.
WARNING
Improper installation,
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.
ML180DFE
adjustment, alteration,
©2016 Lennox Industries, Inc.