Lennox SLP99UHV Series

Page 1
UNIT INFORMATIONUNIT INFORMATION
Service Literature
©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-e󰀩ciency upow, 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 E󰀩ciency re-
quirements.
All specications 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
Specications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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

Lennox SLP99UHV Series Specifications

General

Brand	Lennox
Model	SLP99UHV Series
Category	Furnace
Language	English

Summary

SLP99 UHV Series Unit Overview

Unit Description and Capabilities

General overview of SLP99UHV series units, their features, and capacities.

Important Safety Warnings

Critical safety information regarding installation, electrical hazards, and handling.

SLP99 UHV Specifications

Heating and Cooling Performance Data

Detailed specifications for heating and cooling performance across different models.

SLP99 UHV Optional Accessories

Accessory Categories

Lists optional accessories including cabinet parts, drain kits, controls, filters, and termination kits.

SLP99 UHV Unit Components and Controls

Key Unit Components

Description of essential internal components like transformer, switches, circuit breaker, and integrated control.

Control Configuration and Operation Modes

Guide to configuring thermostat modes, blower speeds, and understanding heating/cooling sequences.

SLP99 UHV Installation and Venting

Placement and Installation Requirements

Guidelines for furnace placement, installation, and approved materials for venting.

Vent Piping Guidelines

Procedures for sizing, routing, and terminating vent pipes according to standards and diagrams.

SLP99 UHV Start-Up, Service, and Maintenance

Initial Unit Start-Up Procedure

Step-by-step guide for priming the condensate trap and initiating furnace operation.

Routine Maintenance Procedures

Recommended maintenance tasks including cleaning blower, replacing filters, and checking pipes.

SLP99 UHV Wiring Diagrams and Operation Sequences

Wiring Diagrams

Electrical diagrams illustrating control board connections and optional components.

Heating Operation Sequences

Flowcharts detailing ignition and heating sequences for different thermostat types.

SLP99 UHV Field Wiring

Non-Communicating Thermostat Wiring

Wiring diagrams and DIP switch settings for non-communicating thermostat applications.