Service Literature
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.
IMPORTANT
This unit must be matched with an indoor coil as specified
with AHRI. For AHRI Certified system match-ups and
expanded ratings, visit www.LennoxPros.com. Coils
previously charged with HCFC-22 must be flushed.
WARNING
To prevent serious injury or death:
1. Lock-out/tag-out before performing maintenance.
2. If system power is required (e.g., smoke detector
maintenance), disable power to blower, remove fan
belt where applicable, and ensure all controllers
and thermostats are set to the "OFF" position before
performing maintenance.
3. Always keep hands, hair, clothing, jewelry, tools, etc.
away from moving parts.
WARNING
Electric Shock Hazard. Can cause injury or
death. Unit must be properly grounded in
accordance with national and local codes.
Line voltage is present at all components when
unit is not in operation on units with single-
pole contactors. Disconnect all remote electric
power supplies before opening access panel.
Unit may have multiple power supplies.
UNIT INFORMATION
SL25KCV (R454B) SERIES OUTDOOR UNITS
Corp. 100102
January 20, 2025
Table of Contents
Specifications ................................................................3
Electrical Data ...............................................................3
Installation ......................................................................9
Unit Placement ..............................................................9
Outdoor Control 7 Segment Display and Push Button 31
Alarms .........................................................................31
Unit Start-Up ...............................................................35
S40 Thermostat ............................................................46
System Overview..........................................................46
er Setup App .................................................................46
Maintenance .................................................................46
Unit Operation ..............................................................66
Decomissioning ............................................................80
Where electrical components are being changed, they
shall be fit for the purpose and to the correct specification.
At all times the manufacturer's maintenance and service
guidelines shall be followed. If in doubt, consult the
manufacturer's technical department for assistance.
Page 1
SL25KCV
IMPORTANT
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