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UNIT INFORMATIONUNIT INFORMATION
Service Literature
©2016 Lennox Industries, Inc. 
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HIHI
 
 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.
 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.
 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.
EL280UHE(X) series units are 80% eciency gas furnac-
es used for upow or horizontal applications only, manu-
factured with Lennox Duralok heat exchangers formed of 
aluminized steel. Units are available in heating capacities 
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. EL280UHE(X) 
model units are equipped with the SureLight® two-stage 
integrated control. EL280UHE(X) unit meets the California 
Nitrogen Oxides (NOx) Standards and California Season-
al Eciency requirements. All units use a redundant gas 
valve to assure safety 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 Performance Data . . . . . . . . . . . . . . . . . . Page 5 
Parts Identication. . . . . . . . . . . . . . . . . . . . . . . . Page 7 
I Unit Components . . . . . . . . . . . . . . . . . . . . . . . . Page 8 
II Installation  . . . . . . . . . . . . . . . . . . . . . . . . .  . Page 26 
III Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 26 
IV Heating System Service Checks . . . . . . . . . Page 26 
V Typical Operating Characteristics . . . . . . . . . Page 30 
VI Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . Page 31 
VII Wiring and Sequence of Operation . . . . . .  Page 34 
VIII Field Wiring and DIP Switch Settings . . .  . Page 38 
IX Troubleshooting Flow Chart .  . . . . . . . . . . . .  Page 42
EL280UHE(X)
Corp 1901-L1 
05/2022
EL280UHE(X) SERIES UNITS