Service Literature
SL280DFV series units are 80% efficiency gas furnaces
used for downflow applications only, manufactured with
Lennox Duralokt heat exchangers formed of aluminized
steel. Units are available in heating capacities of 66,000 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. SL280DFV mod-
el units are equipped with the SureLight
speed integrated control. All units use a redundant gas
valve to assure safety shut−off as required by CSA
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 recommendations only and do not consti-
tute code.
TABLE OF CONTENTS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
IX SureLight Integrated Control TroubleshootingPage 33
Corp. 1002−L1
Revised 10−2010
SL280DFV SERIES UNITS
®
two−stage variable
Page 2
Page 3
Page 4
Page 21
Page 21
. . . . . . . . .
Page 22
. . . . . . . . .
Page 24
Page 24
. . . . . .
Page 28
. . . . . . .
Page 31
Page 1
SL280DFV
WARNING
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 licensed professional 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 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.
© 2010 Lennox Industries Inc.