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UNIT INFORMATION
UNIT INFORMATION
S e r v i c e L i t e r a t u r e
©2016 Lennox Industries, Inc.
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.
SLP99UHV series units are high-efficiency upflow, hori
-
zontal right and left) gas furnaces equipped with variable
capacity gas valve, variable speed combustion air inducer
and variable speed indoor blower motor. All models are
designed only for direct vent (dual pipe) venting system.
SLP99UHV units are available in heating capacities from
66,000 to 132,000 Btuh (19.3 to 38.6 kW) and cooling ap-
plications from 2 to 5 tons (7.0 kW to 17.5 kW). Refer to
Engineering Handbook for proper sizing.
Units are factory-equipped for use with natural gas. Kits
are available for conversion to LPG operation. SLP99UHV
models include a SureLight
®
variable capacity integrated
control that can be used with a Lennox communicating
thermostat as part of a communicating comfort system.
All SLP99UHV units meet the California Nitrogen Oxides
(NOx) Standards and California Seasonal Efficiency re
-
quirements.
All specifications in this manual are subject to change.
Procedures outlined in this manual are presented as rec-
ommendations 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 con-
stitute code.
TABLE OF CONTENTS
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2
Optional Accessories . . . . . . . . . . . . . . . . . . . . . . Page 3
Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4
I Unit Components . . . . . . . . . . . . . . . . . . . . . . . Page 20
II Communicating Thermostat . . . . . . . . . . . . . . Page 44
III Placement and Installation . . . . . . . . . . . . . . Page 47
IV Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 63
V Heating System Service Checks . . . . . . . . . . Page 60
VI Typical Operating Characteristics . . . . . . . . Page 69
VII Maintenanc . . . . . . . . . . . . . . . . . . . . . . . . . . Page 71
VIII Wiring and Sequence of Operation . . . . . Page 74
XI Field Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . Page 82
SLP99UHV
100001
10/2021
SLP99UHV SERIES UNITS
