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© 2013 Lennox Industries Inc.
ML180DF(X)
Service Literature
Corp. 1219-L4
Revised 02/2013
ML180DF series units are mid-efficiency gas furnaces
used for downflow applications only, manufactured with
Lennox Duralokt heat exchangers formed of aluminized
steel. ML180DF units are available in heating capacities of
44,000 to 110,000 Btuh and cooling applications 1.5 to 5
tons. Refer to Product Specifications bulletin for proper siz
ing.
Units are factory equipped for use with natural gas. Kits are
available for conversion to LP/Propane operation.
ML180DF model units are equipped with a hot surface igni
tion system. 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. Pro
cedures outlined in this manual are presented as a recom
mendation only and do not supersede 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 recommended only and do not constitute
code.
TABLE OF CONTENTS
Specifications Page 2.............................
Blower Data Page 4..............................
Parts Identification Page 5.........................
I Unit Components Page 6........................
II Installation Page 14.............................
III Start Up Page 14..............................
IV Heating System Service Checks Page 14.........
V Typical Operating Characteristics Page 19.........
VI Maintenance Page 19..........................
VII Wiring and Sequence of Operation Page 22......
VIII Twinning Page 27.............................
IMPORTANT
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person
al injury or loss of life. Installation and service must
be performed by a qualified installer, service agency
or the gas supplier.
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 discon
nect switch(es). Unit may have multiple
power supplies.
WARNING
Sharp edges.
Be careful when servicing unit to avoid sharp edges
which may result in personal injury.