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UNIT INFORMATIONUNIT INFORMATION
Service Literature
©2016 Lennox Industries, Inc. 
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 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.
 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.
ML296UHV(X) series units are 90% eciency gas furnac-
es used for downow applications only, manufactured with 
Lennox  Duralok  heat  exchangers  formed  of  aluminized 
steel. ML296UHV(X) units are available in heating capac-
ities  of  44,000  to  110,000  Btuh  and  cooling  applications 
up 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 LPG operation. ML296U-
HV(X)  unit  meets  the  California  Nitrogen  Oxides  (NOx) 
Standards  and  California  Seasonal  Eciency  require-
ments. All units use a redundant gas valve to assure safe-
ty shut-o as required by C.S.A.
All  specications  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 (ex-
cept where noted) are recommendations only and do not 
constitute code
TABLE OF CONTENTS
Specications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2
Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 3
I Unit Components . . . . . . . . . . . . . . . . . . . . . . . .  Page 9
II Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 21
III Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 43
IV Heating System Service Checks    . . . . . . . . . Page 44
V Typical Operating Characteristics    . . . . . . . . . Page 47
VI Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . Page 47
VII Wiring and Sequence of Operation     . . . . . . Page 50
ML296UHV(X)
Corp 1903-L1 
Revised 01/2022
ML296UHV(X) SERIES UNITS