Lennox EL296UH045XV36B, EL296UH110XV48C, EL296UH110XV60C, EL296UH135XV60D, EL296UH090XV48C Installation Instructions Manual

© 2017 Lennox Industries Inc.

Dallas, Texas USA

INSTALLATION
INSTRUCTIONS
EL296UHV

ELITE® SERIIES GAS FURNACE
UP/FLOW HORIZONTAL AIR DISCHARGE

507264-03
06/2017
Superseds 03/2017

THIS MANUAL MUST BE LEFT WITH THE

HOMEOWNER FOR FUTURE REFERENCE

This is a safety alert symbol and should never be
ignored. When you see this symbol on labels or in man­uals, be alert to the potential for personal injury or death.

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.

AIR FLOW

AIR FLOW

HORIZONTAL LEFT

UPFLOW

AIR FLOW

HORIZONTAL RIGHT

CAUTION

As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.

Table of Contents

Unit Dimensions - inches (mm) .....................................2

Shipping and Packing List ..............................................3

Safety Information ..........................................................3

Use of Furnace as Construction Heater .........................4

General ........................................................................... 5

Shipping Bolt Removal ...................................................8

Installation - Setting Equipment ...................................... 8

Filters ............................................................................ 13

Duct System .................................................................13

Pipe & Fittings Specications .......................................13

Joint Cementing Procedure .......................................... 15

Venting Practices ..........................................................16

Gas Piping .................................................................... 36

Electrical ....................................................................... 39

NOTICE

A thermostat is not included and must be ordered
separately.

The Lennox icomforti® thermostat must be used in
communicating applications.

In non-communicating applications, the Lennox
ComfortSense® 7500 thermostat may be used, as well
as other non-communicating thermostats.

In all cases, setup is critical to ensure proper system
operation.

Field wiring for both communicating and non­communicating applications is illustrated in diagrams,

which begin on Page 41.

Integrated Control ......................................................... 48

Conventional Thermostat (non-communicating) ...........49

Blower Data .................................................................. 51

On-Board Links.............................................................55

Unit Start Up ................................................................. 57

Gas Pressure Adjustment ............................................. 58

Proper Cumbustion.......................................................59

High Altitude .................................................................59

Combustion Air for Non-Direct Vent Applications .........60

Repair Parts..................................................................60

Other Unit Adjustments................................................. 61

Heating Sequence of Operation ...................................61

Service..........................................................................63

Program Unit Capacity/Size Mode ...............................65

Requirements for Commonwealth of Massachusetts ... 66

Page 1

Unit Dimensions - inches (mm)

1

NOTE - 60C and 60D size units that require second stage

air volumes over 1800 cfm must have one
of the following:

1. Single side return air with transition, to accommodate
20 x 25 x 1 in. cleanable air filter.
Required to maintain proper air velocity.

2. Single side return air with Optional Return Air Base

3. Bottom return air.

4. Return air from both sides.

5. Bottom and

See Blower Performance Ta bles for additional information.

2

Optional Side Return Air Filter Kit is not for use
with the Optional Return Air Base.

one side return air.

1-7/8 (48)

D

3-1/4

(83)

EXHAUST AIR

OUTLET

SUPPLY AIR

OPENING

Flue Condensate Trap Assembly

Furnished for external
field installation
on either side of unit.
(See installation instructions
for additional
information.)

A

B

9/16 (14)

2

OPTIONAL

SIDE RETURN

AIR FILTER KIT

(Either Side)

14-3/4

(375)

16

(406)

7

(178)

(838)

33

COMBUSTION

AIR INTAKE

2

SIDE RETURN

AIR FILTER KIT

(Either Side)

1-1/2 (38)

Front Panel

6-9/16 (167)

12-5/8 (321)

(Either Side)

ELECTRICAL

INLET

(Either Side)

OPTIONAL

Left

9 (229)

Right

23-3/4

(603)

TOP VIEW

27-3/4

(705)

2 (51)
(Either Side)

GAS PIPING INLET

(Either Side)

CONDENSATE
TRAP CONNECTION
(Either Side)

6-1/2 (165)
(Either Side)

23

(584)

1

Side Return
Air Opening
(Either Side)

25

(635)

19-7/16

(494)

14

(356)

9/16
(14)

1-1/2

(38)

AIR FLOW

3/4

(19)

C

1

Bottom Return

Air Opening

FRONT VIEW SIDE VIEW

Model A B C D

EL296UH045XV36B

EL296UH070XV36B

EL296UH090XV36C
EL296UH090XV48C
EL296UH090XV60C
EL296UH110XV48C
EL296UH110XV60C

EL296UH135XV60D 24−1/2 in 622 mm 23−3/8 in 594 mm 23 in 584 mm 11−1/8 in 283 mm

17−1/2 in 446 mm 16−3/8 in 416 mm 16 in 406 mm 7−5/8 in 194 mm

21 in 533 mm 19−7/8 in 505 mm 19−1/2 in 495 mm 9−3/8 in 238 mm

3/4

(19)

5/8

(16)

Page 2

3-1/4

(83)

23-1/2

(597)

1

Bottom Return

Air Opening

1-15/16 (49)

EL296UHV Gas Furnace

NON-DIRECT VENT

INSTALLATION

NON-DIRECT VENT

INSTALLATION

COMBUSTION

AIR INTAKE INSIDE

VENTILATED

CRAWL SPACE

COMBUSTION

AIR INTAKE INSIDE

VENTILATED

ATTIC SPACE

EXHAUST
OUTLET

EXHAUST
OUTLET

The EL296UHV Category IV gas furnace is shipped ready
for installation in the upow or horizontal position. The fur­nace is shipped with the bottom panel in place. The bot­tom panel must be removed if the unit is to be installed

in horizontal or upow applications with bottom return air.

The EL296UHV can be installed as either a Direct Vent
or a Non-Direct Vent gas central furnace.

The furnace is equipped for installation in natural gas
applications. A conversion kit (ordered separately) is re­quired for use in propane/LP gas applications.

NOTE - In Direct Vent installations, combustion air is tak-

en from outdoors and ue gases are discharged outdoors.

In Non-Direct Vent installations, combustion air is taken

from indoors or ventilated attic or crawlspace and ue
gases are discharged outdoors. See for applications in­volving roof termination.

DIRECT VENT INSTALLATION NON-DIRECT VENT

EXHAUST OUTLET

COMBUSTION

AIR INTAKE OUTSIDE

OF HOUSE

INSTALLATION

EXHAUST

OUTLET

Shipping and Packing List

Package 1 of 1 contains

1 - Assembled EL296UHV unit
1 - Bag assembly containing the following:

1 - Snap bushing
1 - Snap plug
1 - Wire tie
1 - Condensate trap
1 - Condensate trap cap
1 - Condensate trap clamp
1 - 2” diameter debris screen
1 - 3/4” Threaded street elbow

Check equipment for shipping damage. If you nd any

damage, immediately contact the last carrier.
The following items may also be ordered separately:
1 - Thermostat
1 - LP/Propane changeover kit
1 - Return air base kit
1 - Horizontal suspension kit
1 - High altitude pressure switch

Safety Information

Figure 1

Figure 2

COMBUSTION

AIR INTAKE

INSIDE

OF HOUSE

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.

DANGER

Danger of explosion.
There are circumstances in which odorant used with LP/

propane gas can lose its scent. In case of a leak, LP/

propane gas will settle close to the oor and may be
difcult to smell. An LP/propane leak detector should be

installed in all LP applications.

Use only the type of gas approved for use with this fur­nace. Refer to unit nameplate.

EL296UHV units are CSA International certied to ANSI

Z21.47 and CSA 2.3 standards.

Building Codes

In the USA, installation of gas furnaces must conform with
local building codes. In the absence of local codes, units
must be installed according to the current National Fuel
Gas Code (ANSI-Z223.1/NFPA 54). The National Fuel
Gas Code is available from the following address:

American National Standards Institute, Inc.
11 West 42nd Street
New York, NY 10036

In Canada, installation must conform with current National
Standard of Canada CSA-B149 Natural Gas and Propane
Installation Codes, local plumbing or waste water codes
and other applicable local codes.

Page 3

In order to ensure proper unit operation in non-direct vent

Gas Unit

Heating Unit Installed Upstream of Cooling Unit

Gas Unit

Dampers

(open during heating operation only)

Dampers

(open during cooling operation only)

Heating Unit Installed Parallell to Air Handler Unit

Air Handler Unit

Evaporator

applications, combustion and ventilation air supply must
be provided according to the current National Fuel Gas
Code or CSA-B149 standard.

Installation Locations

This furnace is CSA International certied for installation

clearances to combustible material as listed on the unit
nameplate and in the table in Figure 12. Accessibility and
service clearances must take precedence over re protec­tion clearances.

NOTE - For installation on combustible oors, the furnace
shall not be installed directly on carpeting, tile, or other
combustible material other than wood ooring.

For installation in a residential garage, the furnace must
be installed so that the burner(s) and the ignition source
are located no less than 18 inches (457 mm) above the

oor. The furnace must be located or protected to avoid

physical damage by vehicles. When a furnace is installed
in a public garage, hangar, or other building that has a
hazardous atmosphere, the furnace must be installed ac­cording to recommended good practice requirements and
current National Fuel Gas Code or CSA B149 standards.

NOTE - Furnace must be adjusted to obtain a temperature

rise within the range specied on the unit nameplate. Fail­ure to do so may cause erratic limit operation and prema­ture heat exchanger failure.

This EL296UHV furnace must be installed so that its elec­trical components are protected from water. Installed in
Combination with a Cooling Coil When this furnace is
used with cooling coils (Figure 3), it shall be installed in
parallel with, or on the upstream side of, cooling coils to
avoid condensation in the heating compartment. With a

parallel ow arrangement, a damper (or other means to
control the ow of air) must adequately prevent chilled ai

from entering the furnace. If the damper is manually op­erated, it must be equipped to prevent operation of either
the heating or the cooling unit, unless it is in the full HEAT
or COOL setting.

When installed, this furnace must be electrically grounded
according to local codes. In addition, in the United States,
installation must conform with the current National Elec­tric Code, ANSI/NFPA No. 70. The National Electric Code
(ANSI/NFPA No. 70) is available from the following ad­dress:

National Fire Protection Association

1 Battery March Park

Quincy, MA 02269

In Canada, all electrical wiring and grounding for the unit
must be installed according to the current regulations of
the Canadian Electrical Code Part I (CSA Standard C22.1)
and/or local codes.

Figure 3

NOTE - This furnace is designed for a minimum contin­uous return air temperature of 60°F (16°C) or an inter­mittent operation down to 55°F (13°C) dry bulb for cases
where a night setback thermostat is used. Return air tem­perature must not exceed 85°F (29°C) dry bulb.

The EL296UHV furnace may be installed in alcoves, clos­ets, attics, basements, garages, crawl spaces and utility

rooms in the upow or horizontal position. This furnace
design has not been CSA certied for installation in mobile

homes, recreational vehicles, or outdoors.

Use of Furnace as Construction Heater

NOTE - Gas furnaces manufactured on or after May 1st
2017 are not permitted to be used in Canada for heating
of buildings or structures under construction.

The following statement only applies to the US. Lennox
does not recommend the use of EL296UHV units as a
construction heater during any phase of construction. Very
low return air temperatures, harmful vapors, construction
dust and operation of the unit with clogged or misplaced

lters may damage the unit.

However, EL296UHV units may be used for heating of

buildings or structures under construction in the US, if the

following conditions are met to ensure proper operation:

• The vent system must be permanently installed per

these installation instructions.

• A room thermostat must control the furnace. The

use of xed jumpers that will provide continuous
heating is not allowed.

• The return air duct must be provided and sealed to

the furnace.

• Return air temperature range between 60°F (16°C)

and 80°F (27°C) must be maintained.

• Air lters must be installed in the system and must

be maintained during construction.

Page 4

• Air lters must be replaced upon construction com-

pletion.

• The input rate and temperature rise must be set per

the furnace rating plate.

• One hundred percent (100%) outdoor air must be

provided for combustion air requirements during
construction. Temporary ducting may supply out­door air to the furnace. Do not connect duct directly
to the furnace. Size the temporary duct following
these instructions in section for Combustion, Dilu­tion and Ventilation Air in a conned space with air
from outside.

• The furnace heat exchanger, components, duct

system, air lters and evaporator coils must be
thoroughly cleaned following nal construction
clean-up.

• All furnace operating conditions (including ignition,

input rate, temperature rise and venting) must

General

These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.
In addition to the requirements outlined previously, the fol-

lowing general recommendations must be considered
when installing a EL296UHV furnace:

• Place the furnace as close to the center of the air
distribution system as possible. The furnace should
also be located close to the vent termination point.

• When the furnace is installed in non-direct vent ap­plications, do not install the furnace where drafts
might blow directly into it. This could cause improp­er combustion and unsafe operation.

• When the furnace is installed in non-direct vent ap­plications, do not block the furnace combustion air
opening with clothing, boxes, doors, etc. Air is need­ed for proper combustion and safe unit operation.

• When the furnace is installed in an attic or other
insulated space, keep insulation away from the fur­nace.

• When the furnace is installed in an unconditioned
space, consider provisions required to prevent
freezing of condensate drain system.

• Please consult the manufacturer of your evaporator
coil for their recommendations on distance required
between the heat exchanger and their drain pan.
Adequate space must be provided between the
drain pan and the furnace heat exchanger.

CAUTION

EL296UHV unit should not be installed in areas normally
subject to freezing temperatures.

WARNING

This product contains a chemical known to the State
of California to cause cancer, birth defects, or other
reproductive harm.

WARNING

Insufcient combustion air can cause headaches,

nausea, dizziness or asphyxiation. It will also cause
excess water in the heat exchanger resulting in rusting
and premature heat exchanger failure. Excessive
exposure to contaminated combustion air will result
in safety and performance related problems. Avoid
exposure to the following substances in the combustion
air supply:

Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine base swimming pool chemicals
Water softening chemicals
De-icing salts or chemicals
Carbon tetrachloride
Halogen type refrigerants
Cleaning solvents (such as perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric acid
Cements and glues
Antistatic fabric softeners for clothes dryers
Masonry acid washing materials

Combustion, Dilution & Ventilation Air

If the EL296UHV is installed as a Non-Direct Vent Fur­nace, follow the guidelines in this section.

NOTE - In Non-Direct Vent installations, combustion air is
taken from indoors or ventilated attic or crawlspace and

ue gases are discharged out-doors.

In the past, there was no problem in bringing in sufcient
outdoor air for combustion. Inltration provided all the air

that was needed. In today’s homes, tight construction
practices make it necessary to bring in air from outside for
combustion. Take into account that exhaust fans, appli-

ance vents, chimneys, and replaces force additional air

that could be used for combustion out of the house.
Unless outside air is brought into the house for combus-

tion, negative pressure (outside pressure is greater than
inside pressure) will build to the point that a downdraft
can occur in the furnace vent pipe or chimney. As a result,
combustion gases enter the living space creating a poten­tially dangerous situation.

In the absence of local codes concerning air for combus­tion and ventilation, use the guidelines and procedures in
this section to install EL296UHV furnaces to ensure ef-

Page 5

cient and safe operation. You must consider combustion
air needs and requirements for exhaust vents and gas
piping. A portion of this information has been reprinted
with permission from the National Fuel Gas Code (ANSI.
Z223.1/NFPA 54). This reprinted material is not the com-

plete and ofcial position of the ANSI on the referenced

subject, which is represented only by the standard in its
entirety.

In Canada, refer to the CSA B149 installation codes.

CAUTION

Do not install the furnace in a corrosive or contaminated
atmosphere. Meet all combustion and ventilation air
requirements, as well as all local codes.

All gas-red appliances require air for the combustion
process. If sufcient combustion air is not available, the
furnace or other appliance will operate inefciently and

unsafely. Enough air must be provided to meet the needs
of all fuel-burning appliances and appliances such as ex­haust fans which force air out of the house. When replac­es, exhaust fans, or clothes dryers are used at the same
time as the furnace, much more air is required to ensure
proper combustion and to prevent a downdraft. Insuf­cient air causes incomplete combustion which can result
in carbon monoxide.

In addition to providing combustion air, fresh outdoor air
dilutes contaminants in the indoor air. These contaminants
may include bleaches, adhesives, detergents, solvents
and other contaminants which can corrode furnace com­ponents.

The requirements for providing air for combustion and
ventilation depend largely on whether the furnace is in-

stalled in an unconned or a conned space.

Unconned Space

An unconned space is an area such as a basement or

large equipment room with a volume greater than 50 cubic
feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of the com­bined input rating of all appliances installed in that space.
This space also includes adjacent rooms which are not
separated by a door. Though an area may appear to be

unconned, it might be necessary to bring in outdoor air

for combustion if the structure does not provide enough air

by inltration. If the furnace is located in a building of tight

construction with weather stripping and caulking around
the windows and doors, follow the procedures in the Air
from Outside section

Conned Space

A conned space is an area with a volume less than 50

cubic feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of
the combined input rating of all appliances installed in that

space. This denition includes furnace closets or small

equipment rooms.

When the furnace is installed so that supply ducts carry
air circulated by the furnace to areas outside the space
containing the furnace, the return air must be handled by
ducts which are sealed to the furnace casing and which
terminate outside the space containing the furnace.This
is especially important when the furnace is mounted on

a platform in a conned space such as a closet or small

equipment room.
Even a small leak around the base of the unit at the plat-

form or at the return air duct connection can cause a po­tentially dangerous negative pressure condition. Air for
combustion and ventilation can be brought into the con-

ned space either from inside the building or from outside.

Air from Inside

If the conned space that houses the furnace adjoins a
space categorized as unconned, air can be brought in by

providing two permanent openings between the two spac­es. Each opening must have a minimum free area of 1
square inch (645 mm2) per 1,000 Btu (.29 kW) per hour of

total input rating of all gas-red equipment in the conned

space. Each opening must be at least 100 square inches
(64516 mm2). One opening shall be within 12 inches (305
mm) of the top of the enclosure and one opening within 12
inches (305 mm) of the bottom. See Figure 4.

EQUIPMENT IN CONFINED SPACE - ALL AIR FROM INSIDE

ROOF TERMINATED

EXHAUST PIPE

OPENINGS

SIDE WALL

TERMINATED

EXHAUST PIPE

(ALTERNATE

LOCATION)

NOTE - Each opening shall have a free area of at least one square inch
per 1,000 Btu (645mm
all equipment in the enclosure, but not less than 100 square inches
(64516mm.

2).

EL296UH

V

2

per .29kW) per hour of the total input rating of

(To Adjacent

Unconfined

Space)

Figure 4

Page 6

Air from Outside

EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE

hour of the total input rating of all equipment in the enclosure.

EQUIPMENT IN CONFINED SPACE

hour of the total input rating of all equipment in the enclosure.

EQUIPMENT IN CONFINED SPACE

If air from outside is brought in for combustion and ventila­tion, the conned space shall be provided with two perma­nent openings. One opening shall be within 12” (305mm)
of the top of the enclosure and one within 12” (305mm) of
the bottom. These openings must communicate directly or
by ducts with the outdoors or spaces (crawl or attic) that
freely communicate with the outdoors or indirectly through
vertical ducts. Each opening shall have a minimum free
area of 1 square inch per 4,000 Btu (645mm2 per 1.17kW)
per hour of total input rating of all equipment in the en­closure. When communicating with the outdoors through
horizontal ducts, each opening shall have a minimum free
area of 1 square inch per 2,000 Btu (645mm2 per .59kW)
per total input rating of all equipment in the enclosure (See
Figure 5). It is also permissible to bring in air for combus-

tion from a ventilated attic (gure 6) or ventilated crawl

space (Figure 7).

(Inlet Air from Crawl Space and Outlet Air to Outside)

(Inlet Air from Ventilated Crawlspace and Outlet Air to Outside)

Roof Terminated

Exhaust Pipe

Inlet Air

(Minimum

Ventilation

Louvers

(Crawl space)

Coupling or
3 in. to 2 in.

Transition

(Field Provided)

Furnace

12 in.(305mm)

Above crawl

space floor)

*Intake Debris Screen Provided)

VENTILATION LOUVERS

OUTLET

AIR

(Each end of attic)

2

per 1.17kW) per

ROOF TERMINATED

EXHAUST PIPE

SIDE WALL

TERMINATED

EXHAUST PIPE

(ALTERNATE

LOCATION)

NOTE-The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645mm

FURNACE

INLET

AIR

Figure 5

(Inlet Air from Ventilated Attic and Outlet Air to Outside)

Ventilation Louvers

Roof Terminated

Exhaust Pipe

*Intake Debris

Screen

(Provided)

Furnace

(Minimum

12 in.(305mm) Above

attic floor)

VENTILATION

LOUVERS

(For unheated

crawl space)

Inlet Air

NOTE-The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645mm
hour of the total input rating of all equipment in the enclosure.

2

per 1.17kW) per

Figure 7

If air from outside is brought in for combustion and ventila­tion, the conned space must have two permanent open­ings. One opening shall be within 12 inches (305 mm) of
the top of the enclosure and one opening within 12 inches
(305 mm) of the bottom. These openings must communi­cate directly or by ducts with the outdoors or spaces (crawl
or attic) that freely communicate with the outdoors or in­directly through vertical ducts. Each opening shall have a
minimum free area of 1 square inch (645 mm2) per 4,000
Btu (1.17 kW) per hour of total input rating of all equipment
in the enclosure. See Figure 5 and Figure 8. When com­municating with the outdoors through horizontal ducts,
each opening shall have a minimum free area of 1 square
inch (645 mm2) per 2,000 Btu (.56 kW) per total input rat­ing of all equipment in the enclosure. See Figure 9.

When ducts are used, they shall be of the same cross-sec­tional area as the free area of the openings to which they
connect. The minimum dimension of rectangular air ducts
shall be no less than 3 inches (75 mm). In calculating free
area, the blocking effect of louvers, grilles, or screens
must be considered. If the design and free area of protec­tive covering is not known for calculating the size opening
required, it may be assumed that wood louvers will have
20 to 25 percent free area and metal louvers and grilles
will have 60 to 75 percent free area. Louvers and grilles

must be xed in the open position or interlocked with the

equipment so that they are opened automatically during
equipment operation.

NOTE-The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645mm

Figure 6

2

per 1.17kW) per

Page 7

EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE

of the total input rating of all equipment in the enclosure.

ROOF TERMINATED

EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE

of the total input rating of all equipment in the enclosure.

r

EXHAUST PIPE

(All Air Through Ventilated Attic)

VENTILATION LOUVERS

(Each end of attic)

OUTLET

AIR

The bolt and washer must be removed before the furnace
is placed into operation. After the bolt and washer have
been removed, the rigid leg will not touch the blower hous­ing.

UNITS WITH 1/2 HP

BLOWER MOTOR

SIDE WALL

TERMINATED

EXHAUST PIPE

(ALTERNATE

LOCATION)

NOTE-The inlet and outlet air openings shall each have a free area of
at least one square inch per 4,000 Btu (645mm

FURNACE

INLET AIR

(Ends 12” above

bottom)

2

per 1.17kW) per hour

Figure 8

(All Air Through Ventilated Attic)

ROOF TERMINATED

EXHAUST PIPE

OUTLET

AIR

SIDE WALL

TERMINATED

EXHAUST PIPE

(ALTERNATE

LOCATION)

NOTE-The inlet and outlet air openings shall each have a free area of
at least one square inch per 4,000 Btu (645mm

FURNACE

VENTILATION LOUVERS

(Each end of attic)

INLET AIR

(Ends 12” above

bottom)

2

per 1.17kW) per hour

Figure 9

Shipping Bolt Removal

Units with 1/2 hp blower motor are equipped with three

exible legs and one rigid leg. The rigid leg is equipped
with a shipping bolt and a at white plastic washer (rather
than the rubber mounting grommet used with a exible

mounting leg). See Figure 10.

remove shipping bolt and washe

RIGID LEG

Figure 10

Installation - Setting Equipment

WARNING

Do not connect the return air duct to the back of the
furnace. Doing so will adversely affect the operation of
the safety control devices, which could result in personal
injury or death.

WARNING

Blower access panel must be securely in place when
blower and burners are operating. Gas fumes, which
could contain carbon monoxide, can be drawn into living
space resulting in personal injury or death.

Upow Applications

The EL296UHV gas furnace can be installed as shipped
in the upow position. Refer to Figure 12 for clearances.
Select a location that allows for the required clearances
that are listed on the unit nameplate. Also consider gas
supply connections, electrical supply, vent connection,
condensate trap and drain connections, and installation
and service clearances [24 inches (610 mm) at unit front].
The unit must be level from side to side. The unit may be

positioned from level to ½” toward the front. See Figure

11.

Allow for clearances to combustible materials as indicated
on the unit nameplate.

Page 8

SETTING EQUIPMENT

END VIEW

Unit must be level side-to-side. Unit may be positioned from level to 1/2” toward the front to aid in draining.

UPFLOW APPLICATION

UNIT

FRONT

1/2” max.

SIDE VIEW

AIR FLOW

FRONT VIEW

UNIT

FRONT

SIDE VIEW

HORIZONTAL APPLICATION

AIR FLOW

FRONT VIEW

Figure 11

UNIT

FRONT

1/2”

max.

Page 9

WARNING

Installation Clearances

Side Return Air

Improper installation of the furnace can result in

personal injury or death. Combustion and ue products

must never be allowed to enter the return air system
or air in the living space. Use sheet metal screws and
joint tape to seal return air system to furnace. In platform
installations with furnace return, the furnace should be
sealed airtight to the return air plenum. A door must
never be used as a portion of the return air duct system.
The base must provide a stable support and an airtight
seal to the furnace. Allow absolutely no sagging, cracks,
gaps, etc.

For no reason should return and supply air duct systems
ever be connected to or from other heating devices

such as a replace or stove, etc. Fire, explosion, carbon

monoxide poisoning, personal injury and/or property
damage could result.

Return Air Guidelines

Return air can be brought in through the bottom or either

side of the furnace installed in an upow application. If the

furnace is installed on a platform with bottom return, make
an airtight seal between the bottom of the furnace and the
platform to ensure that the furnace operates properly and
safely. The furnace is equipped with a removable bottom
panel to facilitate installation.

Markings are provided on both sides of the furnace cab­inet for installations that require side return air. Cut the
furnace cabinet at the maximum dimensions shown on
page 2.

Refer to Engineering Handbook for additional information.

EL296UHV applications which include side return air
and a condensate trap installed on the same side of
the cabinet (trap can be installed remotely within 5

ft.) require either a return air base or eld-fabricated

transition to accommodate an optional IAQ accessory
taller than 14.5”. See Figure 13.

Top

Left Side Right Side

Bottom (Floor)

Top/Plenum 1 in. (25 mm)

*Front 0

Back 0

Sides 0†

Vent 0

Floor 0‡

*Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.

†Allow proper clearances to accommodate condensate trap.
‡For installations on a combustible floor, do not install the furnace

directly on carpeting, tile or other combustible materials other
than wood flooring.

(with transition and filter)

20” X 25” X 1”

(508mmX635mmX 25mm)

Air Filter

Return

Air

Plenum

Transition

Figure 13

Figure 12

Page 10

CONDENSATE

Removing the Bottom Panel

Bottom Panel

See figure 4.

TRAP

AIR FLOW

17−1/2 (446) B Width (50W98)
21 (533) C Width (50W99)
24−1/2 (622) D Width (51W00)

FURNACE

INDOOR AIR

QUALITY

CABINET

(PCO, Filter

Cabinet, etc.)

FRONT VIEW

NOTE- Optional side return air filter kits are not for use with return air base.

1

Both the unit return air opening and the base return air opening must be covered by a single plenum or IAQ cabinet.
Minimum unit side return air opening dimensions for units requiring 1800 cfm or more of air (W x H): 23 x 11 in. (584 x 279 mm).
The opening can be cut as needed to accommodate plenum or IAQ cabinet while maintaining dimensions shown.
Side return air openings must be cut in the field. There are cutting guides stenciled on the cabinet for the side return air
opening. The size of the opening must not extend beyond the markings on the furnace cabinet.

2

To minimize pressure drop, the largest opening height possible (up to 14 inches) is preferred.

Optional Return Air Base

(Upflow Applications Only)

FRONT

IF BASE

IS USED

WITHOUT

IAQ CABINET,

A SINGLE

RETURN AIR

PLENUM

MUST

COVER BOTH

UNIT AND

RETURN

AIR BASE

OPENINGS

OPTIONAL
RETURN
AIR BASE

3−1/4

(83)

7−1/4

(184)

1

23 (584)

Overall

(Maximum)

1

Unit side return air

Opening

SIDE RETURN

5−5/8

AIR OPENINGS

(143)

(Either Side)

26−7/8

(683)

SIDE VIEW

23

(584)

1

Minimum

11 (279)

2

Maximum

14 (356)

1

22−7/16

(570)

Overall

(Maximum)

3/4

(19)

Figure 14

Screw

Figure 15

Removing the Bottom Panel

Remove the two screws that secure the bottom cap to the
furnace. Pivot the bottom cap down to release the bottom
panel. Once the bottom panel has been removed, reinstall
the bottom cap. See Figure 15.

Horizontal Applications

WARNING

Do not install the furnace on its front or back.
See Figure 16.

Bottom Cap

Front Back

Figure 16

Page 11

The EL296UHV furnace can be installed in horizontal ap-

Horizontal Application

HORIZONTAL SUSPENSION KIT

plications with either right- or left-hand air discharge. Re­fer to Figure 17 for clearances in horizontal applications.

Installation Clearances

Metal Strap

(typical)

Internal Brace

(provided with kit)

Right-Hand Discharge

Air

Flow

dnE thgiRdnE tfeL

dnE thgiRdnE tfeL

AIR FLOW

Air

Flow

Bottom (Floor)**

Left-Hand Discharge

Top

AIR FLOW

Bottom (Floor)**

Top 0

Front* 0

Back 0

Ends 0

Vent 0

Floor 0‡

*Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
**An 8” service clearance must be maintained below the unit to
provide for servicing of the condensate trap.
‡For installations on a combustible floor, do not install the furnace
directly on carpeting, tile or other combustible materials other
than wood flooring.

Figure 17

Suspended Installation of Horizontal Unit

This furnace may be installed in either an attic or a crawl­space. Either suspend the furnace from roof rafters or
oor joists, as shown in Figure 18, or install the furnace
on a platform, as shown in Figure 19. A horizontal sus­pension kit (51W10) may be ordered from Lennox or use
equivalent.

NOTE - Heavy-gauge sheet metal straps may be used to
suspend the unit from roof rafters or ceiling joists. When
straps are used to suspend the unit in this way, support
must be provided for both the ends. The straps must not
interfere with the plenum or exhaust piping installation.

Cooling coils and supply and return air plenums must
be supported separately.

Bracket

(typical)

Air

Flow

Figure 18

NOTE - When the furnace is installed on a platform or with
the horizontal suspension kit in a crawlspace, it must be
elevated enough to avoid water damage, accommodate
drain trap and to allow the evaporator coil to drain.

Platform Installation of Horizontal Unit

1 - Select location for unit keeping in mind service and

other necessary clearances. See Figure 17.

2 - Construct a raised wooden frame and cover frame

with a plywood sheet. If unit is installed above

nished space, install an an auxiliary drain pan

under unit. Set unit in drain pan as shown in Figure

19. Leave 8 inches for service clearance below unit
for condensate trap.

3 - Provide a service platform in front of unit. When

installing the unit in a crawl space, a proper support
platform may be created using cement blocks.

4 - Route auxiliary drain line so that water draining from

this outlet will be easily noticed by the homeowner.

5 - If necessary, run the condensate line into a

condensate pump to meet drain line slope
requirements. The pump must be rated for use
with condensing furnaces. Protect the condensate
discharge line from the pump to the outside to avoid
freezing.

6 - Continue with exhaust, condensate and intake

piping installation according to instructions.

Page 12

INTAKE PIPE

EXHAUST PIPE

*Gas connector may be
used for Canadian

able by local authority
having jurisdiction.

SERVICE PLATFORM

*GAS CONNECTION

RAISED

PLATFORM

Figure 19

Return Air -- Horizontal Applications

Return air may be brought in only through the end of a
furnace installed in the horizontal position. The furnace is
equipped with a removable bottom panel to facilitate in­stallation. See Figure 15.

Filters

This unit is not equipped with a lter or rack. A eld-pro­vided high velocity rated lter is required for the unit to
operate properly. Table 1 lists recommended lter sizes. A
lter must be in place whenever the unit is operating.

IMPORTANT

If a highefciency lter is being installed as part of this
system to ensure better indoor air quality, the lter must
be properly sized. Highefciency lters have a higher
static pressure drop than standardefciency glass/foam
lters. If the pressure drop is too great, system capacity

and performance may be reduced.
The pressure drop may also cause the limit to trip more

frequently during the winter and the indoor coil to freeze
in the summer, resulting in an increase in the number of
service calls.

Before using any lter with this system, check the
specications provided by the lter manufacturer against

the data given in the appropriate Lennox Product

Specications bulletin. Additional information is provided

in Service and Application Note ACC002
(August 2000).

TABLE 1

Furnace

Cabinet Width

Side Return Bottom Return

17-1/2” 16 X 25 X 1 (1) 16 X 25 X 1 (1)

21” 16 X 25 X 1 (1) 20 X 25 X 1 (1)

24-1/2” 16 X 25 X 1 (2) 24 X 25 X 1 (1)

Filter Size

Duct System

Use industry-approved standards to size and install the
supply and return air duct system. Refer to ACCA Manual
D. This will result in a quiet and low-static system that has
uniform air distribution.

NOTE - This furnace is not certied for operation in heat­ing mode (indoor blower operating at selected heating
speed) with an external static pressure which exceeds 0.8
inches w.c. Operation at these conditions may result in
improper limit operation.

Supply Air Plenum

If the furnace is installed without a cooling coil, a remov­able access panel should be installed in the supply air
duct. The access panel should be large enough to per­mit inspection of the heat exchanger. The furnace access
panel must always be in place when the furnace is operat­ing and it must not allow leaks.

Return Air Plenum

NOTE - Return air must not be drawn from a room
where this furnace, or any other gas-fueled appliance
(i.e., water heater), or carbon monoxide-producing de-

vice (i.e., wood replace) is installed.

When return air is drawn from a room, a negative pressure
is created in the room. If a gas appliance is operating in

a room with negative pressure, the ue products can be

pulled back down the vent pipe and into the room. This
reverse ow of the ue gas may result in incomplete com­bustion and the formation of carbon monoxide gas. This
raw gas or toxic fumes might then be distributed through­out the house by the furnace duct system.

Return air can be brought in through the bottom or either
side of the furnace (return air brought into either side of

furnace allowed only in upow applications). If a furnace

with bottom return air is installed on a platform, make an
airtight seal between the bottom of the furnace and the
platform to ensure that the unit operates properly and
safely. Use berglass sealing strips, caulking, or equiva­lent sealing method between the plenum and the furnace

cabinet to ensure a tight seal. If a lter is installed, size the
return air duct to t the lter frame.

Pipe & Fittings Specications

All pipe, ttings, primer and solvent cement must conform

with American National Standard Institute and the Ameri­can Society for Testing and Materials (ANSI/ASTM) stan-

dards. The solvent shall be free owing and contain no

lumps, undissolved particles or any foreign matter that
adversely affects the joint strength or chemical resistance
of the cement. The cement shall show no gelation, strati-

cation, or separation that cannot be removed by stirring.
Refer to the table 2 below for approved piping and tting

materials.

Page 13

CAUTION

Solvent cements for plastic pipe are ammable liquids

and should be kept away from all sources of ignition.
Do not use excessive amounts of solvent cement when
making joints. Good ventilation should be maintained to

reduce re hazard and to minimize breathing of solvent

vapors. Avoid contact of cement with skin and eyes.

TABLE 2

PIPING AND FITTINGS SPECIFICATIONS

Schedule 40 PVC (Pipe) D1785

Schedule 40 PVC (Cellular Core Pipe) F891

Schedule 40 PVC (Fittings) D2466

Schedule 40 CPVC (Pipe) F441

Schedule 40 CPVC (Fittings) F438

SDR-21 PVC or SDR-26 PVC (Pipe) D2241

SDR-21 CPVC or SDR-26 CPVC (Pipe) F442

Schedule 40 ABS Cellular Core DWV
(Pipe)

Schedule 40 ABS (Pipe) D1527

Schedule 40 ABS (Fittings) D2468

ABS-DWV (Drain Waste & Vent) (Pipe &
Fittings)

PVC-DWV (Drain Waste & Vent) Pipe &
Fittings)

PRIMER & SOLVENT CEMENT

PVC & CPVC Primer F656

PVC Solvent Cement D2564

CPVC Solvent Cement F493

ABS Solvent Cement D2235

PVC/CPVC/ABS All Purpose Cement
For Fittings & Pipe of the same material

ABS to PVC or CPVC Transition Solvent

Cement

CANADA PIPE & FITTING & SOLVENT

CEMENT

PVC & CPVC Pipe and Fittings

PVC & CPVC Solvent Cement

ABS to PVC or CPVC Transition
Cement

POLYPROPYLENE VENTING SYSTEM

PolyPro® by Duravent

InnoFlue® by Centrotherm

F628

D2661

D2665

ASTM

SPECIFICATION

D2564, D2235,

F493

D3188

MARKING

ULCS636

IMPORTANT

EL296UHV exhaust and intake connections are made
of PVC. Use PVC primer and solvent cement when
using PVC vent pipe. When using ABS vent pipe, use
transitional solvent cement to make connections to the

PVC ttings in the unit.

Use PVC primer and solvent cement or ABS solvent ce-

ment meeting ASTM specications, refer to Table 2. As an

alternate, use all purpose cement, to bond ABS, PVC, or

CPVC pipe when using ttings and pipe made of the same

materials. Use transition solvent cement when bonding
ABS to either PVC or CPVC.

Low temperature solvent cement is recommended during
cooler weather. Metal or plastic strapping may be used for
vent pipe hangers. Uniformly apply a liberal coat of PVC
primer for PVC or use a clean dry cloth for ABS to clean

inside socket surface of tting and male end of pipe to
depth of tting socket.

Canadian Applications Only - Pipe, ttings, primer and
solvent cement used to vent (exhaust) this appliance must
be certied to ULC S636 and supplied by a single manu­facturer as part of an approved vent (exhaust) system. In
addition, the rst three feet of vent pipe from the furnace
ue collar must be accessible for inspection.

Page 14

TABLE 3

OUTDOOR TERMINATION USAGE*

STANDARD CONCENTRIC

Wall Kit

2 inch 3 inch 2 inch

22G44

(US)

4

30G28

(CA)

44J40

(US)

4

81J20

(CA)

1

YES

1

YES

1

YES

1

YES

1

YES

1

YES

Input Size

045

070

090

Vent Pipe

Dia. in.

2

2-1/2

3

2

2-1/2

3

2

2-1/2

3

Flush

Mount Kit

51W11

(US)

51W12

(CA)

3

YES YES

3

YES YES

3

YES YES

3

YES YES

3

YES YES

3

YES YES

3

YES YES YES

3

YES YES YES

3

YES YES YES

2 YES YES YES

110

2-1/2 YES YES

3 YES YES

135 3 YES YES

NOTE - Standard Terminations do not include any vent pipe or elbows external to the structure. Any vent pipe or elbows external to the structure must be included in total
vent length

calculations. See vent length tables.
* Kits must be properly installed according to kit instructions.

1Requires eld-provided outdoor 1-1/2” exhaust accelerator.

2Concentric kits 71M80 and 44W92 include 1-1/2” outdoor accelerator, when used with 045 and 070 input models.
3 Flush mount kits 51W11 and 51W12 includes 1-1/2 in. outdoor exhaust accelerator, required when used with 045, 070 and 090 input models.

4 Termination kits 30G28, 44W92, 44W93 and 81J20 are certied to ULC S636 for use in Canada only.

5 See table 8 for vent accelerator requirements.

Wall Ring

Kit

15F74

1

YES

1

YES

1

YES

1

YES

1

YES

1

YES

1-1.2 inch 2 inch 3 inch

Field

Fabricated

5

YES

5

YES

5

YES

5

YES

5

YES

5

YES

5

YES YES YES

5

YES YES YES

5

YES YES YES

5

YES YES YES

5

YES YES YES

5

YES YES YES

5

YES YES

71M80

(US)

4

44W92

(CA)

2

YES

2

YES

2

YES

2

YES

2

YES

2

YES

69M29

(US)

4

44W92

(CA)

60L46 (US)

4

44W93 (CA)

Joint Cementing Procedure

All cementing of joints should be done according to the

specications outlined in ASTM D 2855.

DANGER

DANGER OF EXPLOSION!

Fumes from PVC glue may ignite during system check.
Allow fumes to dissipate for at least 5 minutes before
placing unit into operation..

1 - Measure and cut vent pipe to desired length.
2 - Debur and chamfer end of pipe, removing any

ridges or rough edges. If end is not chamfered,

edge of pipe may remove cement from tting socket

and result in a leaking joint.

NOTE - Check the inside of vent pipe thoroughly for
any obstruction that may alter furnace operation.

3 - Clean and dry surfaces to be joined.

4 - Test t joint and mark depth of tting on outside of

pipe.

5 - Uniformly apply a liberal coat of PVC primer for

PVC or use a clean dry cloth for ABS to clean inside

socket surface of tting and male end of pipe to
depth of tting socket.

NOTE - Time is critical at this stage. Do not allow
primer to dry before applying cement.

6 - Promptly apply solvent cement to end of pipe and

inside socket surface of tting. Cement should be

applied lightly but uniformly to inside of socket. Take
care to keep excess cement out of socket. Apply
second coat to end of pipe.

7 - Immediately after applying last coat of cement to

pipe, and while both inside socket surface and end
of pipe are wet with cement, forcefully insert end of
pipe into socket until it bottoms out. Turn PVC pipe
1/4 turn during assembly (but not after pipe is fully
inserted) to distribute cement evenly. DO NOT turn
ABS or cellular core pipe.

Page 15

NOTE - Assembly should be completed within 20

Piping Suspension Guidelines

NOTE

r

roof in order to prevent transmission of vibration to the structure.

seconds after last application of cement. Hammer
blows should not be used when inserting pipe.

8 - After assembly, wipe excess cement from pipe at

end of tting socket. A properly made joint will show

a bead around its entire perimeter. Any gaps may

indicate an improper assembly due to insufcient

solvent.

9 - Handle joints carefully until completely set.

Venting Practices

SCHEDULE 40

PVC - 5'

all other pipe* - 3'

Conduct the following test while each appliance is oper­ating and the other appliances (which are not operating)
remain connected to the common venting system. If the
venting system has been installed improperly, you must
correct the system as indicated in the general venting re­quirements section.

WARNING

CARBON MONOXIDE POISONING HAZARD

Failure to follow the steps outlined below for each
appliance connected to the venting system being placed
into operation could result in carbon monoxide poisoning
or death.

The following steps shall be followed for each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation:

* See Piping and Fittings Specifications table

- Isolate piping at the point where it exits the outside wall o

Wall Thickness Guidelines

24” maximum
3/4” minimum

Wall

Figure 20

1 - In areas where piping penetrates joists or interior

walls, hole must be large enough to allow clearance
on all sides of pipe through center of hole using a
hanger.

2 - When furnace is installed in a residence where unit

is shut down for an extended period of time, such
as a vacation home, make provisions for draining
condensate collection trap and lines.

Removal of the Furnace from Common Vent

In the event that an existing furnace is removed from a
venting system commonly run with separate gas applianc­es, the venting system is likely to be too large to properly
vent the remaining attached appliances.

1 - Seal any unused openings in the common venting

system.

2 - Inspect the venting system for proper size and

horizontal pitch. Determine that there is no blockage,

restriction, leakage, corrosion, or other deciencies

which could cause an unsafe condition.

3 - Close all building doors and windows and all

doors between the space in which the appliances
remaining connected to the common venting system

edistuoedisni

are located and other spaces of the building. Turn on
clothes dryers and any appliances not connected to
the common venting system. Turn on any exhaust
fans, such as range hoods and bathroom exhausts,
so they will operate at maximum speed. Do not

operate a summer exhaust fan. Close replace

dampers.

4 - Follow the lighting instructions. Turn on the appliance

that is being inspected. Adjust the thermostat so
that the appliance operates continuously.

5 - After the main burner has operated for 5 minutes,

test for leaks of ue gases at the draft hood relief
opening. Use the ame of a match or candle.

6 - After determining that each appliance connected

to the common venting system is venting properly,
(step 3 return all doors, widows, exhaust fans,

replace dampers, and any other gas-burning

appliances to their previous mode of operation.

7 - If a venting problem is found during any of the

preceding tests, the common venting system must

be modied to correct the problem.

Resize the common venting system to the minimum
vent pipe size determined by using the appropriate ta­bles in Appendix G. (These are in the current standards

Page 16

appliance.

REPLACING FURNACE THAT WAS PART OF A

COMMON VENT SYSTEM

Exhaust Pipe

CHIMNEY

OR GAS

VENT

(Check sizing

for water

heater only)

WATER

FURNACE

(Replaced)

If replacing a furnace which was
commonly vented with another gas appliance, the size
of the existing vent pipe for that gas appliance must be
checked. Without the heat of the original furnace flue
products, the existing vent pipe is probably oversized for
the single water heater or other appliance. The vent
should be checked for proper draw with the remaining

HEATER

OPENINGS

(To Adjacent

Room)

Figure 21

Exhaust Piping (Figure 22, Figure 24 and Figure 25)

Route piping to outside of structure. Continue with instal­lation following instructions given in piping termination
section.

The EL296UHV can be installed as either a Non-Direct
Vent or a Direct Vent gas central furnace.

NOTE - In Non-Direct Vent installations, combustion air is
taken from indoors or ventilated attic or crawlspace and

ue gases are discharged outdoors. In Direct Vent instal­lations, combustion air is taken from outdoors and ue
gases are discharged outdoors.

Intake and exhaust pipe sizing -- Size pipe according to

tables 4 and 5. Count all elbows inside and outside the
home. Table 4 lists the minimum vent pipe lengths per­mitted. Table 5 lists the maximum pipe lengths permitted.

Regardless of the diameter of pipe used, the standard roof
and wall terminations described in section Exhaust Piping
Terminations should be used. Exhaust vent termination
pipe is sized to optimize the velocity of the exhaust gas
as it exits the termination. Refer to table 8. In some appli­cations which permit the use of several different sizes of
vent pipe, a combination vent pipe may be used. Contact
Lennox’ Application Department for assistance in sizing
vent pipe in these applications.

NOTE - The exhaust collar on all models is sized to ac­commodate 2” Schedule 40 vent pipe. In horizontal ap­plications, any transition to exhaust pipe larger than 2”
must be made in vertical runs of the pipe. Therefore a 2”
elbow must be added before the pipe is transitioned to
any size larger than 2”. This elbow must be added to the
elbow count used to determine acceptable vent lengths.
Contact the Application Department for more information
concerning sizing of vent systems which include multiple
pipe sizes.

CAUTION

Do not discharge exhaust into an existing stack or
stack that also serves another gas appliance. If vertical
discharge through an existing unused stack is required,
insert PVC pipe inside the stack until the end is even
with the top or outlet end of the metal stack.

The exhaust vent pipe operates under positive pressure
and must be completely sealed to prevent leakage of
combustion products into the living space.

Vent Piping Guidlines

NOTE - Lennox has approved the use of DuraVent® and
Centrotherm manufactured vent pipe and terminations
as an option to PVC. When using the PolyPro® by Du­raVent or InnoFlue® by Centrotherm venting system the
vent pipe requirements stated in the unit installation in­struction – minimum & maximum vent lengths, termination
clearances, etc. – apply and must be followed. Follow the
instructions provided with PoyPro by DuraVent and Inno­Flue by Centrotherm venting system for assembly or if re­quirements are more restrictive. The PolyPro by Duravent
and InnoFlue by Centrotherm venting system must also
follow the uninsulated

CAUTION

Exhaust Pipe

Horizontal

Gas Furnace

NOTE -

ward unit. A minimum of 1/4” (6mm) drop for each 12” (305mm)
of horizontal run is mandatory for drainage.

NOTE - Exhaust pipe MUST be glued to furnace exhaust fittings.

NOTE - Exhaust piping should be checked carefully to make

sure there are no sags or low spots.

12” ma x

of straight pip

e

12”Min .

Figure 22

TABLE 4

MINIMUM VENT PIPE LENGTHS

EL296UHV MODEL MIN. VENT LENGTH*

045, 070, 090, 110, 135

*Any approved termination may be added to the minimum length list­ed.

15 ft. or 5 ft plus 2 elbows or

10 ft plus 1 elbow

Page 17

Piping Size Process

What is the

furnace capacity?

1

045, 070, 090,

110 or 135?

Which style termination

2

3

4

5

being used?

Standard or concentric?

See table 3.

Which needs

most elbows?

Intake or

exhaust?

How many elbows?
Count all elbows inside
and outside house.

Desired pipe size?

2”, 2-1/2”, 3”

IMPORTANT

Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.

What is the altitude of

6

the furnace installation?

Use table 5 or 6 to find
max intake or exhaust pipe

7

length. Includes all vent
pipe and elbows inside
and outside the house.

Figure 23

Page 18

TABLE 5

Maximum Allowable Intake or Exhaust Vent Length in Feet

NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake and Exhaust must
be same pipe size.

Standard Termination at Elevation 0 - 4500 ft

Number

Of 90°

Elbows

Used

045 070 090 110 135 045 070 090 110 135 045 070 090 110 135

1 81 66 44 22

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

115 115 93 58

138 137 118 118 114

2 76 61 39 19 110 110 88 53 133 132 113 113 109

3 71 56 34 14 105 105 83 48 128 127 108 108 104

4 66 51 29

100 100 78 43 123 122 103 103 99

5 61 46 24 95 95 73 38 118 117 98 98 94

n/a

n/a

6 56 41 19 90 90 68 33 113 112 93 93 89

7 51 36 14 85 85 63 28 108 107 88 88 84

8 46 31

9 41 26 75 75 53 18 98 97 78 78 74

n/a

n/a

80 80 58 23 103 102 83 83 79

10 36 21 70 70 48 13 93 92 73 73 69

Standard Termination Elevation 4500 - 10,000 ft

Number

Of 90°

Elbows

Usedl

045 070 090 11 0 135 045 070 090 11 0 135 045 070 090 11 0 135

1 81 66 44

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

115 115 93 58

138 137 118 118 11 4

2 76 61 39 110 110 88 53 133 132 11 3 113 109

3 71 56 34 105 105 83 48 128 127 108 108 104

4 66 51 29 100 100 78 43 123 122 103 103 99

5 61 46 24 95 96 73 38 118 117 98 98 94

n/a n/a

n/a

6 56 41 19 90 90 68 33 113 112 93 93 89

7 51 36 14 85 85 63 28 108 107 88 88 84

8 46 31

9 41 26 75 75 53 18 98 97 78 78 74

n/a

10 36 21 70 70 48 13 93 92 73 73 69

See concentric terminations next page.

80 80 58 23 103 102 83 83 79

Page 19

TABLE 5 Continued

Maximum Allowable Intake or Exhaust Vent Length in Feet

NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total.
Both Intake and Exhaust must be same pipe size.

Concentric Termination at Elevation 0 - 4500 ft

Number

Of 90°

Elbows

Used

045 070 090 110 135 045 070 090 110 135 045 070 090 110 135

1 73 58 42 22

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

105 105 89 54

121 121 114 114 105

2 68 53 37 17 100 100 84 49 116 116 109 109 100

3 63 48 32 12 95 95 79 44 111 111 104 104 95

4 58 43 27

90 90 74 39 106 106 99 99 90

5 53 38 22 85 85 69 34 101 101 94 94 85

n/a

n/a

6 48 33 17 80 80 64 29 96 96 89 89 80

7 43 28 12 75 75 59 24 91 91 84 84 75

8 38 23

9 33 18 65 65 49 14 81 81 74 74 65

n/a

n/a

70 70 54 19 86 86 79 79 70

10 28 13 60 60 44 n/a 76 76 69 69 60

Concentric Termination Elevation 4500 - 10,000 ft

Number

Of 90°

Elbows

Usedl

045 070 090 11 0 135 045 070 090 11 0 135 045 070 090 11 0 135

1 73 58 42

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

105 105 89 54

121 121 114 114 105

2 68 53 37 100 100 84 49 116 116 109 109 100

3 63 48 32 95 95 79 44 111 111 104 104 95

4 58 43 27 90 90 74 39 106 106 99 99 90

5 53 38 22 85 85 69 34 101 101 94 94 85

n/a n/a

n/a

6 48 33 17 80 80 64 29 96 96 89 89 80

7 43 28 12 75 75 59 24 91 91 84 84 75

8 38 23

9 33 18 65 65 49 14 81 81 74 74 65

n/a

10 28 13 60 60 44 n/a 76 76 69 69 60

70 70 54 19 86 86 79 79 70

Page 20

TABLE 6

Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or Basement Using Ventilated

Attic or Crawl Space For Intake Air in Feet

NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total.
Both Intake and Exhaust must be same pipe size.

NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the
total vent length calculation

Standard Termination at Elevation 0 - 4500 ft

Number

Of 90°

Elbows

Used

045 070 090 110 135 045 070 090 110 135 045 070 090 110 135

1 71 56 34 14

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

100 100 78 43

118 117 98 98 94

2 66 51 29 9 95 95 73 38 113 112 93 93 89

3 61 46 24 4 90 90 68 33 108 107 88 88 84

4 56 41 19

85 85 63 28 103 102 83 83 79

5 51 36 14 80 80 58 23 98 97 78 78 74

n/a

n/a

6 46 31 9 75 75 53 18 93 92 73 73 69

7 41 26 4 70 70 48 13 88 87 68 68 64

8 36 21

9 31 16 60 60 38 3 78 77 58 58 54

n/a

n/a

65 65 43 8 83 82 63 63 59

10 26 11 55 55 33 n/a 73 72 53 53 49

Standard Termination Elevation 4500 - 10,000 ft

Number

Of 90°

Elbows

Usedl

045 070 090 11 0 135 045 070 090 11 0 135 045 070 090 11 0 135

1 71 56 34

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

100 100 78 43

118 117 98 98 94

2 66 51 29 95 95 73 38 113 112 93 93 89

3 61 46 24 90 90 68 33 108 107 88 88 84

4 56 41 19 85 85 63 28 103 102 83 83 79

5 51 36 14 80 80 58 23 98 97 78 78 74

n/a n/a

n/a

6 46 31 9 75 75 53 18 93 92 73 73 69

7 41 26 4 70 70 48 13 88 87 68 68 64

8 36 21

9 31 16 60 60 38 3 78 77 58 58 54

n/a

10 26 11 55 55 33 n/a 73 72 53 53 49

65 65 43 8 83 82 63 63 59

Page 21

TYPICAL EXHAUST AND INTAKE PIPE CONNECTIONS IN UPFLOW DIRECT OR

NON-DIRECT VENT APPLICATIONS

EXHAUST

2”

INTAKE

2”

EXHAUSTINTAKE

2”

2”

or

3”

TRANSITION

*2”

3”

TRANSITION

*2”

DO NOT transition

from smaller to larger

pipe in horizontal runs

of exhaust pipe.

* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.

Figure 24

2”

2”

TYPICAL EXHAUST AND INTAKE PIPE CONNECTIONS IN HORIZONTAL DIRECT OR NON-DIRECT VENT

APPLICATIONS

12” max.

EXHAUST

2”

INTAKE

EXHAUST

*2”

INTAKE

* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.

(RIGHT HAND DISCHARGE SHOWN)

2”

or

2”

2”

3”

*2”

2”

2”

TRANSITION

*2”

2”

or

2”

3”

*2”

45°

MAX

2”

*2”

2”

SIDE VIEW

DO NOT transition

from smaller to larger

pipe in horizontal runs

of exhaust pipe.

45°

MAX

Figure 25

Page 22

Intake Piping

TYPICAL AIR INTAKE PIPE CONNECTIONS

(preferred) or with an elbow rotated to face down.

The EL296UHV furnace may be installed in either direct
vent or non-direct vent applications. In non-direct vent

applications, when intake air will be drawn into the furnace
from the surrounding space, the indoor air quality must be
considered and guidelines listed in Combustion, Dilution
and Ventilation Air section must be followed.

Follow the next two steps when installing the unit in Direct
Vent applications, where combustion air is taken from

outdoors and ue gases are discharged outdoors. The
provided air intake screen must not be used in direct
vent applications (outdoors).

1 - Use transition solvent cement or a sheet metal screw

to secure the intake pipe to the inlet air connector.

2 - Route piping to outside of structure. Continue with

installation following instructions given in general
guidelines for piping terminations and intake and
exhaust piping terminations for direct vent sections.
Refer to table 5 for pipe sizes.

TYPICAL AIR INTAKE PIPE CONNECTIONS

UPFLOW NON−DIRECT

VENT APPLICATIONS

INTAKE
DEBRIS

SCREEN

(Provided)

NOTE - Debris screen and elbow may be rotated, so that
screen may be positioned to face forward or to either side.

Figure 26

HORIZONTAL NON−DIRECT VENT APPLICATIONS

(Horizontal Right−Hand Air Discharge Application Shown)

PVC pipe

coupling

OR

INTAKE

DEBRIS

SCREEN

(Provided)

NOTE - Debris screen may be positioned straight out

Figure 27

Follow the next two steps when installing the unit in Non­Direct Vent applications where combustion air is taken

from indoors or ventilated attic or crawlspace and ue

gases are discharged outdoors.

1 - Use eld-provided materials and the factory-

provided air intake screen to route the intake piping
as shown in Figure 26 or Figure 27. Maintain a
minimum clearance of 3” (76mm) around the air
intake opening. The air intake opening (with the
protective screen) should always be directed

forward or to either side in the upow position, and

either straight out or downward in the horizontal
position.

The air intake piping must not terminate too close

to the ooring or a platform. Ensure that the intake
air inlet will not be obstructed by loose insulation

or other items that may clog the debris screen.

2 - If intake air is drawn from a ventilated attic (Figure

28) or ventilated crawlspace (Figure 29) the exhaust
vent length must not exceed those listed in table 6.
If 3” diameter pipe is used, reduce to 2” diameter
pipe at the termination point to accommodate the
debris screen.

3 - Use a sheet metal screw to secure the intake pipe

to the connector, if desired.

Page 23

CAUTION

EQUIPMENT IN CONFINED SPACE

(Inlet Air from Ventilated Attic and Outlet Air to Outside)

NOTE-The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645mm

2

per 1.17kW) per

hour of the total input rating of all equipment in the enclosure.

Ventilation Louvers

Inlet Air

(Minimum

12 in.(305mm) Above

attic floor)

Roof Terminated

Exhaust Pipe

Furnace

*Intake Debris

Screen

(Provided)

EQUIPMENT IN CONFINED SPACE

If this unit is being installed in an application with
combustion air coming in from a space serviced by an
exhaust fan, power exhaust fan, or other device which
may create a negative pressure in the space, take care
when sizing the inlet air opening. The inlet air opening
must be sized to accommodate the maximum volume
of exhausted air as well as the maximum volume of
combustion air required forall gas appliances serviced
by this space.

Figure 28

(Inlet Air from Ventilated Crawlspace and Outlet Air to Outside)

Roof Terminated

Exhaust Pipe

Inlet Air

(Minimum

Ventilation

Louvers

(Crawl space)

(Field Provided)

NOTE-The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645mm
hour of the total input rating of all equipment in the enclosure.

Furnace

Coupling or
3 in. to 2 in.

Transition

12 in.(305mm)

Above crawl

space floor)

*Intake Debris Screen Provided)

2

per 1.17kW) per

General Guidelines for Vent Terminations

In Non-Direct Vent applications, combustion air is taken

from indoors or ventilated attic or crawlspace and the ue

gases are discharged to the outdoors. The EL296UHV is
then classied as a non-direct vent, Category IV gas fur­nace.

In Direct Vent applications, combustion air is taken from

outdoors and the ue gases are discharged to the out­doors. The EL296UHV is then classied as a direct vent,

Category IV gas furnace.
In both Non-Direct Vent and Direct Vent applications, the

vent termination is limited by local building codes. In the
absence of local codes, refer to the current National Fuel
Gas Code ANSI Z223-1/NFPA 54 in U.S.A., and current
CSA-B149 Natural Gas and Propane Installation Codes in
Canada for details.

Position termination according to location given in Figure
31 or Figure 32. In addition, position termination so it is
free from any obstructions and 12” above the average
snow accumulation.

At vent termination, care must be taken to maintain protec­tive coatings over building materials (prolonged exposure
to exhaust condensate can destroy protective coatings).
It is recommended that the exhaust outlet not be located
within 6 feet (1.8m) of an outdoor AC unit because the
condensate can damage the painted coating.

NOTE - See table 7 for maximum allowed exhaust pipe
length without insulation in unconditioned space during
winter design temperatures below 32°F (0°C). If required
exhaust pipe should be insulated with 1/2” (13mm) Ar­maex or equivalent. In extreme cold climate areas, 3/4”
(19mm) Armaex or equivalent may be necessary. Insu­lation must be protected from deterioration. Armaex with
UV protection is permissable. Basements or other en­closed areas that are not exposed to the outdoor ambient
temperature and are above 32 degrees F (0°C) are to be
considered conditioned spaces.

IMPORTANT

Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.

IMPORTANT

For Canadian Installations Only:
In accordance to CSA International B149 installation

codes, the minimum allowed distance between the
combustion air intake inlet and the exhaust outlet of other
appliances shall not be less than 12 inches (305mm).

Figure 29

Page 24

TABLE 7

Maximum Allowable Exhaust Vent Pipe Length (in ft.) Without Insulation In Unconditioned Space For

Winter Design Temperatures Two - Stage High Efciency Furnace

Winter Design

Temperatures1 °F

(°C)

32 to 21

(0 to -6)

Vent Pipe

Diameter

2 in 21 18 33 30 46 42 30 30 n/a n/a

2-1/2 in 16 n/a 26 n/a 37 n/a 36 n/a n/a n/a

045 070 090 110 135

PVC

2

PP

PVC

3 in 12 12 21 21 30 30 29 29 42 42

20 to 1

(-7 to -17)

0 to -20

(-18 to -29)

1Refer to 99% Minimum Design Temperature table provided in the current edition of the ASHRAE Fundamentals Handbook.

2 Poly-Propylene vent pipe (PP) by Duravent and Centrotherm.

NOTE - Concentric terminations are the equivalent of 5’ and should be considered when measuring pipe length.

NOTE - Maximum unisulated vent lengths listed may include the termination(vent pipe exterior to the structure) and cannot exceed 5 linear feet or
the maximum allowable intake or exhaust vent length listed in table 5 or 6 which ever is less.

NOTE - If insulation is required in an unconditioned space, it must be located on the pipe closest to the furnace. See Figure 30.

2 in 11 9 19 17 28 25 27 24 n/a n/a

2-1/2 in 7 n/a 14 n/a 21 n/a 20 n/a n/a n/a

3 in n/a n/a 9 9 16 16 14 14 23 23

2 in 6 4 12 10 19 16 18 15 n/a n/a

2-1/2 in n/a n/a 7 n/a 13 n/a 12 n/a n/a n/a

3 in n/a n/a n/a n/a 8 8 7 7 13 13

Unit Input Size

2

PP

PVC

2

PP

PVC

2

PP

PVC

2

PP

Conditioned

Space

Conditioned

Space

Figure 30

Pipe Insulation

Unconditioned

Space

Exhaust

Pipe

Intake

Pipe

Page 25

VENT TERMINATION CLEARANCES

FOR NON-DIRECT VENT INSTALLATIONS IN THE US AND CANADA

K

D

E

L

B

C

F

G

A

B

J

A

M

I

H

INSIDE CORNER

DETAIL

VENT TERMINAL

AIR SUPPLY INLET

AREA WHERE TERMINAL
IS NOT PERMITTED

Fixed

Closed

Operable

B

Fixed

Closed

Operable

B

B

A =

B =

C =

D =

E =

F =

G =

H =

I =

J =

K =

L =

M =

US Installations

1

Canadian Installations

2

12 inches (305mm) or 12 in. (305mm)

above average snow accumulation.

12 inches (305mm) or 12 in. (305mm)

above average snow accumulation.

Clearance above grade, veranda,

porch, deck or balcony

Clearance to window or

door that may be opened

4 feet (1.2 m) below or to side of opening;

1 foot (30cm) above opening

6 inches (152mm) for appliances <10,000

Btuh (3kw), 12 inches (305mm) for

appliances > 10,000 Btuh (3kw) and

<100,000 Btuh (30kw), 36 inches (.9m)

for appliances > 100,000 Btuh (30kw)

Clearance to permanently

closed window

Vertical clearance to ventilated soffit

located above the terminal within a

horizontal distance of 2 feet (610 mm)

from the center line of the terminal

Clearance to unventilated soffit

Clearance to outside corner

Clearance to inside corner

tended above meter / regulator assembly

Clearance to service regulator

vent outlet

Clearance to non-mechanical air

pliance

ply inlet

Clearance above paved sidewalk or

paved driveway located on public property

Clearance under veranda, porch, deck or balcony

* 12”

* Equal to or greater than soffit depth.

*

* 3 feet (.9m)

* 12”

3 feet (.9m) within a height 15 feet (4.5m)

above the meter / regulator assembly

3 feet (.9m)

6 inches (152mm) for appliances <10,000

Btuh (3kw), 12 inches (305mm) for

appliances > 10,000 Btuh (3kw) and

<100,000 Btuh (30kw), 36 inches (.9m)

for appliances > 100,000 Btuh (30kw)

3 feet (.9m) above if within 10 feet

(3m) horizontally

6 feet (1.8m)

7 feet (2.1m)†

12 inches (305mm)‡

1

In accordance with the current ANSI Z223.1/NFPA 54 Natural Fuel Gas Code

2

In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code
† A vent shall not terminate directly above a sidewalk or paved driveway that is
located between two single family dwellings and serves both dwellings.

‡ Permitted only if veranda, porch, deck or balcony is fully open
on a minimum of two sides beneath the floor. Lennox recommends
avoiding this location if possible.

4 feet (1.2 m) below or to side of opening;

1 foot (30 cm) above opening

7 feet (2.1m)†

* Equal to or greater than soffit depth.

* Equal to or greater than soffit depth.

* Equal to or greater than soffit depth.

* No minimum to outside corner * No minimum to outside corner

3 feet (.9m) within a height 15 feet (4.5m)

above the meter / regulator assembly

*12 inches (305mm)‡

**

*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA
B149.1, clearance will be in accordance with local installation
codes and the requirements of the
lation instructions.”

Figure 31

Page 26

VENT TERMINATION CLEARANCES

FOR DIRECT VENT INSTALLATIONS IN THE US AND CANADA

INSIDE CORNER

DETAIL

G

D

A

E

B

L

C

Fixed

F

Closed

Operable

B

Operable

B

B

VENT TERMINAL

AIR SUPPLY INLET

US Installations

A =

B =

Clearance above grade, veranda,

porch, deck or balcony

Clearance to window or

door that may be opened

12 inches (305mm) or 12 in. (305mm)

above average snow accumulation.

6 inches (152mm) for appliances <10,000

pliances > 10,000 Btuh (3kw) and <50,000

pliances > 50,000 Btuh (15kw)

C =

D =

E =

F =

G =

H =

I =

J =

K =

L =

M =

1

In accordance with the current ANSI Z223.1/NFPA 54 Natural Fuel Gas Code

2

In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code

† A vent shall not terminate directly above a sidewalk or paved driveway that is located
between two single family dwellings and serves both dwellings.

‡ Permitted only if veranda, porch, deck or balcony is fully open on a minimum of
two sides beneath the floor. Lennox recommends avoiding this location if possible.

Clearance to permanently

closed window

Vertical clearance to ventilated soffit

located above the terminal within a

horizontal distance of 2 feet (610mm)

from the center line of the terminal

Clearance to unventilated soffit

Clearance to outside corner

Clearance to inside corner

tended above meter / regulator assembly

Clearance to service regulator

vent outlet

3 feet (.9m) within a height 15 feet (4.5m)

Clearance to non-mechanical air

pliance

ply inlet

Clearance above paved sidewalk or

paved driveway located on public property

Clearance under veranda, porch, deck or balcony

* Equal to or greater than soffit depth

* Equal to or greater than soffit depth* Equal to or greater than soffit depth

* No minimum to outside corner

above the meter / regulator assembly

6 inches (152mm) for appliances <10,000

pliances > 10,000 Btuh (3kw) and <50,000

pliances > 50,000 Btuh (15kw)

3 feet (.9m) above if within 10 feet

* 12”

*

*

3 feet (.9m)

(3m) horizontally

* 7 feet (2.1m)

*12 inches (305mm)‡

H

B

Fixed

Closed

A

J

AREA WHERE TERMINAL
IS NOT PERMITTED

1

12 inches (305mm) or 12 in. (305mm)

above average snow accumulation.

6 inches (152mm) for appliances <10,000

Btuh (3kw), 12 inches (305mm) for

appliances > 10,000 Btuh (3kw) and

<100,000 Btuh (30kw), 36 inches (.9m)

for appliances > 100,000 Btuh (30kw)

I

M

Canadian Installations

K

2

* 12”

* Equal to or greater than soffit depth* Equal to or greater than soffit depth

* No minimum to outside corner

*

3 feet (.9m) within a height 15 feet (4.5m)

above the meter / regulator assembly

3 feet (.9m)

6 inches (152mm) for appliances <10,000

Btuh (3kw), 12 inches (305mm) for

appliances > 10,000 Btuh (3kw) and

<100,000 Btuh (30kw), 36 inches (.9m)

for appliances > 100,000 Btuh (30kw)

6 feet (1.8m)

7 feet (2.1m)†

12 inches (305mm)‡

*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA
B149.1, clearance will be in accordance with local installation
codes and the requirements of the gas supplier and these
installation instructions.”

Figure 32

Page 27

Details of Intake and Exhaust Piping Terminations for

Exiting Exhaust and Intake Vent

Direct Vent Installations

NOTE - In Direct Vent installations, combustion air is taken

from outdoors and ue gases are discharged to outdoors.
NOTE - Flue gas may be slightly acidic and may adverse-

ly affect some building materials. If any vent termination
is used and the ue gasses may impinge on the building
material, a corrosion-resistant shield (minimum 24 inches
square) should be used to protect the wall surface. If the
optional tee is used, the protective shield is recommend­ed. The shield should be constructed using wood, plastic,
sheet metal or other suitable material. All seams, joints,
cracks, etc. in the affected area should be sealed using an
appropriate sealant. See Figure 41.

Intake and exhaust pipes may be routed either horizontal­ly through an outside wall or vertically through the roof. In
attic or closet installations, vertical termination through the
roof is preferred. Figure 33 through Figure 40 show typical
terminations.

1 - Intake and exhaust terminations are not required

to be in the same pressure zone. You may exit the
intake on one side of the structure and the exhaust
on another side (Figure 34). You may exit the
exhaust out the roof and the intake out the side of
the structure (Figure 35).

2 - Intake and exhaust pipes should be placed as close

together as possible at termination end (refer to
illustrations). Maximum separation is 3” (76MM)
on roof terminations and 6” (152MM) on side wall
terminations.

NOTE - When venting in different pressure zones,
the maximum separation requirement of intake and
exhaust pipe DOES NOT apply.

3 - On roof terminations, the intake piping should

terminate straight down using two 90° elbows (See
Figure 33).

4 - Exhaust piping must terminate straight out or up as

shown. A reducer may be required on the exhaust
piping at the point where it exits the structure to
improve the velocity of exhaust away from the
intake piping. See table 8.

NOTE - Care must be taken to avoid recirculation of
exhaust back into intake pipe.

5 - On eld-supplied terminations for side wall exit,

exhaust piping may extend a maximum of 12 inches
(305MM) for 2” PVC and 20 inches (508MM) for 3”
(76MM) PVC beyond the outside wall. Intake piping
should be as short as possible. See Figure 41.

6 - On eld-supplied terminations, a minimum distance

between the end of the exhaust pipe and the end of
the intake pipe without a termination elbow is 8” and
a minimum distance of 6” with a termination elbow.
See Figure 41.

7 - If intake and exhaust piping must be run up a

side wall to position above snow accumulation or
other obstructions, piping must be supported. At
least one bracket must be used within 6” from the
top of the elbow and then every 24” (610mm) as
shown in Figure 41, to prevent any movement in

any direction. When exhaust and intake piping
must be run up an outside wall, the exhaust piping
must be terminated with pipe sized per table 8.The
intake piping may be equipped with a 90° elbow
turndown. Using turndown will add 5 feet (1.5m) to
the equivalent length of the pipe.

Inches(mm)

8” (203mm) MIN

12” (305mm) ABOVE

AVERAGE SNOW
ACCUMULATION

3” (76mm) OR

2” (51mm) PVC

PROVIDE SUPPORT

FOR INTAKE AND

EXHAUST LINES

DIRECT VENT ROOF TERMINATION KIT

3”(76mm) MAX.

(15F75 or 44J41)

UNCONDITIONED

ATTIC SPACE

Figure 33

Exiting Exhaust and Intake Vent

(different pressure zone)

Exhaust

Pipe

Furnace

Inlet Air
(Minimum 12 in.
305 MM) above

grade or snow

accumulation

Figure 34

(different pressure zone)

Roof T

erminated

Exhaust Pipe

Inlet Air

Furnace

(Minimum 12 in.

305 MM) above

grade or snow

accumulation

Figure 35

Page 28

TABLE 8

41W92 or 41W93 (Canada)

(30G28 or 81J20)

EXHAUST PIPE TERMINATION SIZE REDUCTION

EL296UHV

MODEL

*045 and 070 1-1/2” (38MM)

*090 2” (51MM)

110 2” (51MM)

135 2” (51MM)

*EL296UHV-045, -070 and -090 units with the ush mount termination

must use the 1-1/2”accelerator supplied with the kit.

Termination

Pipe Size

8 - A multiple furnace installation may use a group

of up to four terminations assembled together
horizontally, as shown in Figure 39.

FIELD-PROVIDED

QUIRED TO ADAPT

LARGER VENT PIPE

SIZE TO TERMINATION.

EXHAUST

AIR

INTAKE

AIR

OUTSIDE

WALL

CLAMP

(Not Furnished)

INTAKE

AIR

INTAKE

AIR

DIRECT VENT CONCENTRIC WALL TERMINATION

71M80, 69M29 or 60L46 (US)

EXHAUST

AIR

12” (305mm) Min.

above grade or

cumulation.

GRADE

2” EXTENSION FOR 2” PVC
PIPE1” EXTENSION FOR 3”
PVC PIPE

4''

FURNACE

INTAKE

PIPE

FLAT
SIDE

1-1/2” ACCELERATOR

FLUSH-MOUNT SIDE WALL TERMINATION KIT

51W11 (US) or 51W12 (Canada)

Figure 36

12” (305mm)

Minimum

Above Average

Snow

Accumulation

INTAKE

FURNACE

EXHAUST

PIPE

GLUE EXHAUST

END FLUSH INTO

TERMINATION

FLASHING

(Not Furnished)

Figure 38

EXHAUST

VENT

5”

(127mm)

INTAKE

AIR

18” MAX.

(457mm)

EXHAUST VENT

Inches (mm)

INTAKE

AIR

optional intake elbow

Side View

OPTIONAL VENT TERMINATION FOR MULTIPLE UNIT

INSTALLATION OF DIRECT VENT WALL TERMINATION KIT

12”

(305mm)

5-1/2”

(140mm)

Front View

12” (305mm) Min.

above grade or

cumulation.

Figure 39

DIRECT VENT APPLICATION

USING EXISTING CHIMNEY

STRAIGHT-CUT OR

ANGLE-CUT IN DIRECTION

OF ROOF SLOPE *

SHEET METAL STRAP

(Clamp and sheet metal strap

must be field−installed to support

CLAMP

the weight of the termination kit.)

FIELD-PROVIDED

REDUCER MAY BE REQUIRED

TO ADAPT LARGER VENT

PIPE SIZE TO TERMINATION

DIRECT VENT CONCENTRIC ROOFTOP TERMINATION

71M80, 69M29 or 60L46 (US)

44W92 or 44W93 (Canada)

Figure 37

Page 29

3” - 8”

8” - 12”

(203mm - 305mm)

Minimum 12” (305MM)

above chimney top

plate or average snow

accumulation

*SIZE TERMINATION

PIPE PER TABLE 7.

NOTE - Do
tical discharge through an existing unused chimney or stack is required, insert piping
inside
trated. In any exterior portion of chimney, the exhaust vent must be insulated.

INTAKE PIPE

INSULATION (optional)

SHEET

METAL TOP

PLATE

INSULATE
TO FORM

SEAL

(76mm-

203mm)

SHOULDER OF FITTINGS

PROVIDE SUPPORT

OF PIPE ON TOP PLATE

3” - 8”

(76mm-

203mm)

ALTERNATE

INTAKE PIPE

EXTERIOR

PORTION OF

CHIMNEY

Figure 40

NOTE − FIELD−PROVIDED

REQUIRED TO ADAPT

LARGER VENT PIPE SIZE

* WALL

SUPPORT

C1

B

2

B

2

FIELD FABRICATED WALL TERMINATION

REDUCER MAY BE

TO TERMINATION

C1

A

E

D

B

STRAIGHT

APPPLICATION

A

Intake
Elbow

D

B

EXTENDED

APPLICATION

C2

C2

D

B

A

E

D

B

A

A− Minimum clearance

above grade or average

snow accumulation

B− Maximum horizontal

separation between

intake and exhaust

C1 -Minimum from end of

exhaust to inlet of intake

C2 -Minimum from end of

exhaust to inlet of intake

D− Maximum exhaust

pipe length

E− Maximum wall support

distance from top of each

pipe (intake/exhaust)

See maximum allowable venting tables for venting
lengths with this arrangement.

* Use wall support every 24” (610 mm). Use two
wall supports if extension is greater than

24” (610 mm) but less than 48” (1219 mm).
NOTE − One wall support must be within 6” (152 mm)
from top of each pipe (intake and exhaust) to prevent
movement in any direction.

ALTERNATE TERMINATIONS (TEE & FORTY−FIVE DEGREE ELBOWS ONLY)

D

B

Exhaust

D

1

C

A

D

E

12”

C

A

1

The exhaust termination tee should be connected to the 2” or 3” PVC flue pipe as shown in the illustration. In
horizontal tee applications there must be be a minimum of 3 ft away from covered patios or any living ares and

cannot be within 3 ft of a window. Do not use an accelerator in applications that include an exhaust termination
tee. The accelerator is not required.

2

As required. Flue gas may be acidic and may adversely affect some building materials. If a side wall vent

termination is used and flue gases will impinge on the building materials, a corrosion−resistant shield
(24 inches square) should be used to protect the wall surface. If optional tee is used, the protective shield
is recommended. The shield should be constructed using wood, sheet metal or other suitable material.
All seams, joints, cracks, etc. in affected area, should be sealed using an appropriate sealant.

3

Exhaust pipe 45° elbow can be rotated to the side away from the combustion air inlet to direct exhaust
away from adjacent property. The exhaust must never be directed toward the combustion air inlet.

Intake
Elbow

1

C

A

E

B

2

A

3

D

1

12”

C

A− Clearance above

grade or average snow

accumulation

B− Horizontal

separation between

intake and exhaust

C− Minimum from

end of exhaust to

inlet of intake

D− Exhaust pipe length

E− Wall support distance

from top of each pipe

(intake/exhaust)

Front View of

Intake and Exhaust

Intake

Exhaust

Figure 41

2” (51mm)

Vent Pipe

12” (305 mm)

12” (305 mm)

6” (152 mm)

2” (51MM)

Vent Pipe

12” (305 mm) Min.12” (305 mm) Min.

6” (152 mm) Min.
24” (610 mm) Max.

9” (227 mm) Min.

12” (305 mm) Min.
16” (405 mm) Max.

6” (152 mm) Max.

3” (76mm)

Vent Pipe

12” (305 mm)

6” (152 mm)6” (152 mm)

8” (203 mm)8” (203 mm)

6” (152 mm)6” (152 mm)

20” (508 mm)

6” (152 mm)

3” (76MM)

Vent Pipe

6” (152 mm) Min.
24” (610 mm) Max.

9” (227 mm) Min.

12” (305 mm) Min.
20” (508 mm) Max.

6” (152 mm) Max.

Page 30

Details of Exhaust Piping Terminations for Non-Direct
Vent Applications

Exhaust pipes may be routed either horizontally through
an outside wall or vertically through the roof. In attic or
closet installations, vertical termination through the roof
is preferred. Figure 42 and Figure 43 show typical termi­nations.

1 - Exhaust piping must terminate straight out or up as

shown. The termination pipe must be sized as listed

in table 8.The specied pipe size ensures proper

velocity required to move the exhaust gases away
from the building.

2 - On eld supplied terminations for side wall exit,

exhaust piping may extend a maximum of 12 inches
(305MM) for 2” PVC and 20 inches (508MM) for 3”
(76MM) PVC beyond the outside wall.

DIRECT VENT APPLICATION

USING EXISTING CHIMNEY

3” - 8”

(203mm - 305mm)

Minimum 12” (305MM)

above chimney top

plate or average snow

accumulation

*SIZE TERMINATION

PIPE PER TABLE 7.

8” - 12”

INSULATION (optional)

INSULATE
TO FORM

SEAL

INTAKE PIPE

SHEET

METAL TOP

PLATE

(76mm­203mm)

STRAIGHT-CUT OR

ANGLE-CUT IN DIRECTION

OF ROOF SLOPE *

SHOULDER OF FITTINGS

PROVIDE SUPPORT

OF PIPE ON TOP PLATE

3” - 8”
(76mm­203mm)

ALTERNATE

INTAKE PIPE

EXTERIOR

PORTION OF

CHIMNEY

12” (305mm)

ABOVE AVE.

SNOW

ACCUMULATION

3” (76mm) OR

2” (51mm) PVC

PROVIDE SUPPORT

FOR EXHAUST LINES

UNCONDITIONED

ATTIC SPACE

NON-DIRECT VENT ROOF TERMINATION KIT

(15F75 or 44J41)

Figure 42

3 - If exhaust piping must be run up a side wall

to position above snow accumulation or other
obstructions, piping must be supported every 24
inches (610MM). When exhaust piping must be run
up an outside wall, any reduction in exhaust pipe

size must be done after the nal elbow.

4 - Distance between exhaust pipe terminations on

multiple furnaces must meet local codes.

Crawl Space and Extended Horizontal Venting

NOTE - Do
tical discharge through an existing unused chimney or stack is required, insert piping
inside
trated. In any exterior portion of chimney, the exhaust vent must be insulated.

Figure 43

Venting In A Crawl Space

Basement Floor

Lennox provides kit 51W18 (USA) and kit 15Z70 (Cana-

da) to install 2” or 3” PVC exhaust piping through the oor

joists and into the the crawl space. See Figure 44.
This kit can also be used as a supplemental drain for in-

stallations with condensate run back in the vent pipe (ie.
long horizontal runs, unconditioned spaces, etc.).

KIT 51W18

(USA)

KIT 15Z70

(CANADA)

Figure 44

Page 31

Condensate Piping

This unit is designed for either right- or left-side exit of

condensate piping in upow applications. In horizontal

applications, the condensate trap must extend below the
unit. An 8” service clearance is required for the conden­sate trap. Refer to Figure 45 and Figure 47 for condensate
trap locations. Figure 53 shows trap assembly using 1/2”
PVC or 3/4” PVC.

NOTE - If necessary the condensate trap may be installed
up to 5’ away from the furnace. Use PVC pipe to connect
trap to furnace condensate outlet. Piping from furnace
must slope down a minimum of 1/4” per ft. toward trap.

1 - Determine which side condensate piping will exit

the unit, location of trap, eld-provided ttings and

length of PVC pipe required to reach available
drain.

2 - Use a large at head screw driver or a 1/2” drive

socket extension and remove plug (Figure 45) from
the cold end header box at the appropriate location
on the side of the unit. Install provided 3/4 NPT

street elbow tting into cold end header box. Use
Teon tape or appropriate pipe dope.

NOTE - Cold end header box drain plugs are facto­ry installed. Check the unused plug for tightness to
prevent leakage.

3 - Install the cap over the clean out opening at the

base of the trap. Secure with clamp. See Figure 53.

4 - Install drain trap using appropriate PVC ttings,

glue all joints. Glue the provided drain trap as
shown in Figure 53. Route the condensate line to
an open drain. Condensate line must maintain a
1/4” downward slope from the furnace to the drain.

5 - Figure 48 and Figure 49 show the furnace and

evaporator coil using a separate drain. If necessary
the condensate line from the furnace and evaporator
coil can drain together. See Figure 50, Figure 51 and
Figure 52. Upow furnace (Figure 51) - In upow

furnace applications the eld provided vent must

be a minimum 1” to a maximum 2” length above
the condensate drain outlet connection. Any length

above 2” may result in a ooded heat exchanger

if the combined primary drain line were to become
restricted. Horizontal furnace (Figure 52) - In

horizontal furnace applications the eld provided

vent must be a minimum 4” to a maximum 5” length
above the condensate drain outlet connection.

Any length above 5” may result in a ooded heat

exchanger if the combined primary drain line were
to become restricted.

CONDENSATE TRAP AND PLUG LOCATIONS

(Unit shown in upflow position)

Trap

(same on

right side)

1-1/2 in.

NOTE - In upflow applications where side return

sate trap, filter rack must be installed beyond
condensate trap or trap must be re-located to
avoid interference.

Figure 45

NOTE - In horizontal applications it is recommended to
install a secondary drain pan underneath the unit and trap
assembly.

NOTE - Appropriately sized tubing and barbed tting may
be used for condensate drain. Attach to the drain on the
trap using a hose clamp. See Figure 46.

Field Provided Drain Components

Elbow

Tubing

Hose Clamp

Figure 46

Rubber

Grommet

Plug

(same on left side)

Barbed Fitting

CAUTION

Do not use copper tubing or existing copper condensate
lines for drain line.

Page 32

6 - If unit will be started immediately upon completion

CONDENSATE TRAP LOCATIONS

minimum 1/4” per ft. toward trap

of installation, prime trap per procedure outlined in
Unit Start-Up section.

(Unit shownin upflow position withremote trap)

FieldProvidedVent

Min.1” AboveCondensate

Drain

1”

2” Max.

Connection

Min.

Condensate line must slope downward away from the trap
to drain. If drain level is above condensate trap, conden­sate pump must be used. Condensate drain line should
be routed within the conditioned space to avoid freezing of
condensate and blockage of drain line. If this is not possi­ble, a heat cable kit may be used on the condensate trap
and line. Heating cable kit is available from Lennox in var­ious lengths; 6 ft. (1.8m) - kit no. 26K68; 24 ft. (7.3m) - kit
no. 26K69; and 50 ft. (15.2m) - kit no. 26K70.

Furnace With Evaporator
Coil Using A Separate Drain

*5’ max.

PVCPipe Only

Trap CanBeInstalleda

Maximum 5’ From Furnac

e

To Drain

*Piping from furnace must slope down a

Figure 47

Furnace with Evaporator Coil Using a Separate Drain

(Unit shown in horizontal left-hand discharge position)

(Trap at coil is optional)

Field Provided Vent
(1” min. 2” max. above
condensate connection)

Condensate

Drain

Connection

Evaporator drain

line required

Figure 48

Evaporator

Coil

Drain

Pan

(Trap at coil is optional)

Piping from furnace and evaporator coil must slope down a minimum 1/4” per ft. toward trap

Field Provided Vent
(4” min. to 5” max. above
condensate connection)

4”min

5”max

5’ max.

PVC Pipe Only

Condensate

DrainConnection

.

Figure 49

Page 33

IMPORTANT

When combining the furnace and evaporator coil
drains together, the A/C condensate drain outlet must
be vented to relieve pressure in order for the furnace
pressure switch to operate properly.

Condensate Trap With Optional Overflow Switch

From Evaporator Coil

HorizontalFurnace4 ” Min.to5” Max.above

condensatedrain connection)

FurnaceCondensate

Connection

Drain

Optional

Furnace with Evaporator
Coil Using a Common Drain

(Trap at coil is optional)

(1” min.to2” Max.above

condensatedrain connection)

Condensate

Connection

Drain

Figure 51

Evaporator drain

line required

Drain

Pan

Figure 50

Furnace with Evaporator Coil Using a Common Drain

(Unit shown in horizontal left−hand discharge position)

Evaporator

Coil

(Trap at coil is optional)

Piping from furnace and evaporator coil must slope

down a minimum 1/4” per ft. toward trap

Condensate Drain

Connection

5’ max.

PVC Pipe Only

Figure 52

4”min

5”max

(4” min.to5” Max.above

condensatedrain

connection)

Page 34

Optional Condensate Drain Connection

TRAP / DRAIN ASSEMBLY USING 1/2” PVC OR 3/4” PVC

Adapter 3/4 inch slip X

3/4 inch mpt (not furnished)

90° Street Elbow
3/4 inch PVC
(not furnished)

Condensate Drain

Connection In Unit

90° Street Elbow
3/4 inch PVC
( furnished)

To

Trap

Optional DrainPipingFrom Trap

Drain Assembly for 1/2 inch Drain Pipe

1/2 inch PVC Pipe

(Not Furnished)

90° Elbow

1/2 inch PVC

(Not Furnished)

To

Drain Assembly for 3/4 inch Drain Pipe

Drain

1(25 mm) Min.
2 (50 mm) Max.
AboveTop Of
Condensate Drain
Connection In Unit

Elbow 3/4 inch PVC

90°

(Not Furnished)

1/2 inch PVC Pipe

(Not Furnished)

Adapter 3/4 inch slip X

3/4 inch mpt (not furnished)

V

ent

5 Feet

Maximum

3/4 inch PVC Pipe

(Not Furnished)

Coupling 3/4 inch slip X slip

Drain Trap

Assembly

(Furnished)

Condensate Drain

Connection In Unit

(Not Furnished)

90° Elbow

3/4 inch PVC

(Not Furnished)

To

Drain

DrainTrapAssembly

(Furnished)

7

(178)

Drain Trap
Clean Out

90° Elbow

3/4 inch PVC

(Not Furnished)

T

o

Coupling 3/4 inch slip X slip

Drain

DrainTrap Assembly with 1/2 inch Piping

1 (25 mm) Min. 2 (50 mm) Max. AboveTop
Of Condensate Drain Connection In Unit

(Not Furnished)

Vent

1/2 inch

Condensate Drain

Connection In Unit

To

Drain

Figure 53

DrainTr ap Assembly with 3/4 inch Piping

1 (25 mm) Min. 2 (50 mm) Max. AboveTop
Of Condensate Drain Connection In Unit

Vent

3/4 inch

Condensate Drain

Connection In Unit

To

Drain

Page 35

Gas Piping

Gas supply piping should not allow more than 0.5”W.C.
drop in pressure between gas meter and unit. Supply gas
pipe must not be smaller than unit gas connection.

6 - In some localities, codes may require installation of

a manual main shut-off valve and union (furnished
by installer) external to the unit. Union must be of
the ground joint type.

CAUTION

If a exible gas connector is required or allowed by the

authority that has jurisdiction, black iron pipe shall be
installed at the gas valve and extend outside the furnace

cabinet. The exible connector can then be added

between the black iron pipe and the gas supply line.

WARNING

Do not over torque (800 in-lbs) or under torque (350 in­lbs) when attaching the gas piping to the gas valve.

1 - Gas piping may be routed into the unit through either

the left- or right-hand side. Supply piping enters into
the gas valve from the side of the valve as shown

in gure 55. Connect the gas supply piping into the

gas valve. The maximum torque is 800 in lbs and
minimum torque is 350 in lbs when when attaching
the gas piping to the gas valve.

2 - When connecting gas supply, factors such as length

of run, number of ttings and furnace rating must

be considered to avoid excessive pressure drop.
Table 9 lists recommended pipe sizes for typical
applications.

NOTE - Use two wrenches when connecting gas
piping to avoid transferring torque to the manifold.

3 - Gas piping must not run in or through air ducts,

clothes chutes, chimneys or gas vents, dumb
waiters or elevator shafts. Center gas line through
piping hole. Gas line should not touch side of unit.
See Figure 55 and Figure 56.

4 - Piping should be sloped 1/4 inch per 15 feet (6mm

per 5.6m) upward toward the gas meter from the
furnace. The piping must be supported at proper
intervals, every 8 to 10 feet (2.44 to 3.05m), using
suitable hangers or straps. Install a drip leg in
vertical pipe runs to serve as a trap for sediment or
condensate.

5 - A 1/8” N.P.T. plugged tap or pressure post is located

on the gas valve to facilitate test gauge connection.
See Figure 62.

IMPORTANT

Compounds used on threaded joints of gas piping must

be resistant to the actions of liquied petroleum gases.

Leak Check

After gas piping is completed, carefully check all piping

connections (factory- and eld-installed) for gas leaks.

Use a leak detecting solution or other preferred means.

Never use an open ame to test for gas leaks. Check all

connections using a commercially available soap solution

made specically for leak detection.

The furnace must be isolated from the gas supply system
by closing its individual manual shut-off valve during any
pressure testing of the gas supply system at pressures
greater than or equal to 1/2 psig (3.48 kPa, 14 inches w.c.).

MANUAL MAIN SHUT-OFF

VALVE WILL NOT HOLD

NORMAL TEST PRESSURE

1/8” N.P. T. PLUGGED TAP

Figure 54

CAP

FURNACE

ISOLATE

GAS VALV E

IMPORTANT

When testing pressure of gas lines, gas valve must be
disconnected and isolated. See Figure 54. Gas valves
can be damaged if subjected to pressures greater than
1/2 psig (3.48 kPa).

WARNING

FIRE OR EXPLOSION HAZARD

Failure to follow the safety warnings exactly could result
in serious injury, death, or property damage. Never use

an open ame to test for gas leaks. Check all connections

using a commercially available soap solution made

specically for leak detection. Some soaps used for leak

detection are corrosive to certain metals. Carefully rinse
piping thoroughly after leak test has been completed.

Page 36

Upflow Application

Left Side Piping

(Standard)

MANUAL

MAIN SHUT-OFF

VALV E

GROUND

JOINT

UNION

MANUAL

MAIN SHUT-OFF

VALV E

GROUND

JOINT

UNION

DRIP LEG

1/2” NPT

FIELD

PROVIDED

AND INSTALLED

NOTE - BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET

Figure 55

Horizontal Applications

Possible Gas Piping Configurations

MANUAL

MAIN SHUT-OFF

VALV E

GROUND

JOINT

UNION

DRIP LEG

Upflow Application

Right Side Piping

(Alternate)

Horizontal Application

Left-Side Air Discharge

1/2” NPT

MANUAL

MAIN SHUT-OFF

VALV E

GROUND

JOINT

UNION

DRIP LEG

DRIP LEG

Horizontal Application

Right-Side Air Discharge

FIELD

PROVIDED

AND INSTALLED

NOTE - BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET

Figure 56

MANUAL

MAIN SHUT-OFF

VALV E

GROUND

JOINT

UNION

DRIP LEG

Page 37

TABLE 9

Gas Pipe Capacity - ft3/hr (m3/hr)

Nominal

Iron Pipe

Size Inches

(mm)

1/2

(12.7)

3/4

(19.05)

1

(25.4)

1-1/4

(31.75)

1-1/2

(38.1)

2

(50.8)

2-1/2

(63.5)

3

(76.2)

Internal

Diameter

inches

(mm)

.622

(17.799)

.824

(20.930)

1.049

(26.645)

1.380

(35.052)

1.610

(40.894)

2.067

(52.502)

2.469

(67.713)

3.068

(77.927)

10

(3.048)

172

(4.87)

360

(10.19)

678

(19.19)

1350

(38.22)

2090

(59.18)

4020

(113.83)

6400

(181.22)

11300

(319.98)

20

(6.096)

118

(3.34)

247

(7.000)

466

(13.19)

957

(27.09)

1430

(40.49)

2760

(78.15)

4400

(124.59)

7780

(220.30)

30

(9,144)

95

(2.69)

199

(5.63)

374

(10.59)

768

(22.25)

1150

(32.56)

2220

(62.86)

3530

(99.95)

6250

(176.98)

40

(12,192)

81

(2.29)

170

(4.81)

320

(9.06)

657

(18.60)

985

(27.89)

1900

(53.80)

3020

(85.51)

5350

(151.49)

Length of Pipe - feet (m)

50

(15.240)

72

(2.03)

151

(4.23)

284

(8.04)

583

(16.50)

873

(24.72)

1680

(47.57)

2680

(75.88)

4740

(134.22)

60

(18.288)

65

(1.84)

137

(3.87)

257

(7.27)

528

(14.95)

791

(22.39)

1520

(43.04)

2480

(70.22)

4290

(121.47)

70

(21.336)

60

(1.69)

126

(3.56)

237

(6.71)

486

(13.76)

728

(20.61)

1400

(39.64)

2230

(63.14)

3950

(111.85)

80

(24.384)

56

(1.58)

117

(3.31)

220

(6.23)

452

(12.79)

677

(19.17)

1300

(36.81)

2080

(58.89)

3670

(103.92)

NOTE - Capacity given in cubic feet (m3 ) of gas per hour and based on 0.60 specic gravity gas.

90

(27.432)

52

(1.47)

110

(3.11)

207

(5.86)

424

(12.00)

635

(17.98)

1220

(34.55)

1950

(55.22)

3450

(97.69)

100

(30,480)

50

(1.42)

104

(2.94)

195

(5.52)

400

(11.33)

600

(17.00)

1160

(32.844)

1840

(52.10)

3260

(92.31)

Page 38

Electrical

INTERIOR MAKE-UP BOX INSTALLATION

WARNING

Electrostatic discharge can affect
electronic components. Take care
during unit installation and service to

ELECTROSTATIC

DISCHARGE

(ESD)

Precautions and

Procedures

protect the unit’s electronic controls.
Precautions will help to avoid control
exposure to electrostatic discharge
by putting the unit, the control and the
technician at the same electrostatic
potential. Touch hand and all tools
on an unpainted unit surface before
performing any service procedure to
neutralize electrostatic charge.

WARNING

Electric Shock Hazard. Can cause injury or
death. Unit must be properly grounded in
accordance with national and local codes.

WARNING

Fire Hazard. Use of aluminum wire with this product may

result in a re, causing property damage, severe injury

or death. Use copper wire only with this product.

The unit is equipped with a eld make-up box on the left

hand side of the cabinet. The make-up box may be moved
to the right side of the furnace to facilitate installation. If
the make-up box is moved to the right side, clip the wire
ties that bundle the wires together. The excess wire must
be pulled into the blower compartment. Secure the excess
wire to the existing harness to protect it from damage.

MAKE-UP

BOX

Right Side

The power supply wiring must meet Class I restrictions.
Protected by either a fuse or circuit breaker, select circuit
protection and wire size according to unit nameplate.

CAUTION

Failure to use properly sized wiring and circuit breaker
may result in property damage. Size wiring and circuit

breaker(s) per Product Specications bulletin (EHB) and

unit rating plate.

NOTE - Unit nameplate states maximum current draw.
Maximum over-current protection allowed is shown in ta­ble 10.

TABLE 10

EL296UHV Maximum Over-Current

045V36B, 070V36B,
090V36C, 090V48C,

110V48C

090V60C, 110V60C,

135V60D

Holes are on both sides of the furnace cabinet to facilitate
wiring.

Install a separate (properly sized) disconnect switch near
the furnace so that power can be turned off for servicing.
Before connecting the thermostat or the power wiring,
check to make sure the wires will be long enough for ser­vicing at a later date. Remove the blower access panel to
check the length of the wire.

Complete the wiring connections to the equipment. Use
the provided unit wiring diagram and the eld wiring di­agrams shown in table 11 and Figure 60. Use 18-gauge
wire or larger that is suitable for Class II rating for thermo­stat connections.

Electrically ground the unit according to local codes or, in
the absence of local codes, according to the current Na­tional Electric Code (ANSI/NFPA No. 70). A green ground

wire is provided in the eld make-up box. NOTE - The

EL296UHV furnace contains electronic components that
are polarity sensitive. Make sure that the furnace is wired
correctly and is properly grounded.

One line voltage “ACC” 1/4” spade terminal is provided on
the furnace integrated control. Any electronic air cleaner
or other accessory rated up to one amp can be connect­ed to this terminal with the neutral leg of the circuit being
connected to the one of the provided neutral terminals.
See Figure 61 for control conguration. This terminal is
energized when the indoor blower is operating.

15

20

Figure 57

Refer to Figure 60 for unit schematic and eld wiring. See
Figure 58 and Figure 59 for icomfort Wi-Fi® thermostat
wiring in communicating applications. Table 11 shows DIP
switch and on-board link settings for non-communicating
thermostat applications. Typical wiring schematic is shown
in Figure 60.

Page 39

An unpowered, normally open (dry) set of contacts with

a 1/4” spade terminal “HUM” are provided for humidier

connections and may be connected to 24V or 120V. Any

humidier rated up to one amp can be connected to these
terminals. In 120V humidier applications the neutral leg of

the circuit can be connected to one of the provided neutral
terminals. This terminal is energized in the heating mode.

Install the room thermostat according to the instructions

provided with the thermostat. See table 11 for eld wiring

connections in varying applications. If the furnace is being
matched with a heat pump, refer to the instruction pack­aged with the dual fuel thermostat.

Thermostat Selection

CAUTION

Field wiring for both communicating and non­communicating applications is illustrated in diagrams,
which begin on the next page.

Non-Communicating

In non-communicating applications the EL296UHV
is designed to operate in a SINGLE-STAGE mode or
TWOSTAGE mode using a conventional thermostat.

For optimal performance in non-communicating applica­tions, Lennox recommends use of a ComfortSense® 7000
high quality electronic digital thermostat or any other with
adjustable settings for 1st stage / 2nd stage on / off differ­entials and adjustable stage timers.

Communicating

In communicating applications the icomfort Wi-Fi® ther­mostat must be used. Refer to the instructions provided
with the thermostat for installation, set-up and operation.
In communicating system all unused thermostat wire in
the wire bundle needs to be terminated inside and out.
The extra wires can terminate on the ‘C” terminal of the
icomfort communication terminal strip. (RSBus). Using an
additional wire come off ”C” terminal and wire nut all the
extra wires together. Termination on the outdoor control
must match the indoor control.

Indoor Blower Speeds

Non-Communicating

When the thermostat is set to “FAN ON,” the indoor blower

will run continuously at a eld selectable percentage of

the second-stage cooling speed when there is no cooling
or heating demand. The factory default setting is 38% of
cool speed. When the EL296UHV is running in the heat­ing mode,the indoor blower will run on the heating speed
designated by the positions of DIP switches 11, 12 and 13.
When there is a cooling demand, the indoor blower will
run on the cooling speed designated by the positions of
DIP switches 5 and 6. First stage cooling will run at 70%
cool speed.

Communicating

NOTE - When the EL296UHV is used with icomfort Wi­F® thermostat, proper indoor blower speed selections are
made by the communicating thermostat.

When the thermostat is set to “FAN ON,” the indoor blower

will run at setting determined during system conguration.

When there is a heating demand the fan will run on heat-

ing speeds for ring rate. When there is a cooling demand,
the fan will run on the rst stage and second stage cooling

speed set using the icomfort WiFi® thermostat in the in­staller setup mode. The factory default is based upon 400
CFM a ton.

Generator Use - Voltage Requirements

The following requirements must be kept in mind when
specifying a generator for use with this equipment:

• The furnace requires 120 volts (Range: 102 volts to
132 volts)

• The furnace operates at 60 Hz + 5% (Range: 57 Hz
to 63 Hz)

• The furnace integrated control requires both correct
polarity and proper ground. Both polarity and proper
grounding should be checked before attempting to
operate the furnace on either permanent or tempo­rary power

• Generator should have a wave form distortion of
less than 5% THD (total harmonic distortion)

Page 40

icomfort Wi-Fi

®

Thermostat with Furnace and

Non-Communicating Outdoor Unit

icomfort®­ENABLED
FURNACE

icomfort Wi-Fi®

THERMOSTAT

NON-COMMUNICATING

OUTDOOR AIR

CONDITIONING UNIT -

1 OR 2 STAGE

icomfort Wi-Fi® Thermostat
icomfort

®

-Enabled Indoor Furnace

Non-Communicating Outdoor Air Conditioner

OPTIONAL
OUTDOOR

AIR SENSOR

OPTIONAL

DISCHARGE

AIR SENSOR

icomfort Wi-Fi® Thermostat with Furnace and

icomfort

®

-ENABLED Outdoor Unit

icomfort Wi-Fi® Thermostat
icomfort

®

-Enabled Indoor Furnace

icomfort

®

-Enabled Outdoor Air Conditioner or Heat Pump

icomfort®­ENABLED
FURNACE

icomfort

®

- ENABLED

OUTDOOR AIR CONDITIONING

OR HEAT PUMP UNIT

OPTIONAL
OUTDOOR

AIR SENSOR

OPTIONAL

DISCHARGE

AIR SENSOR

CLIP ON-BOARD LINK
W915 (Y1 TO Y2) FOR

TWO-STAGE OPERATION

icomfort Wi-Fi®
THERMOSTAT

Indoor Unit
Controller

Outdoor Unit

Icomfort Wi-Fi

®

thermostat

Single wire to
terminal C

Single wire to
terminal C

Unused wires

Unused wires

Communicating systems using the Icomfort Wi-Fi

®

mostat wires between the thermostat and the furnace/air handler control and four
wires between
mostat cable with more than four wires is used, the extra wires must be properly
connected to avoid electrical noise. The wires must not be left disconnected.

Use wire nuts to bundle the four unused wires at each end of the cable. A
single wire should then be connected to the indoor unit end of the wire bundle
and attached to the “C” terminals as shown in the diagram above.

Figure 58

Page 41

Optional Accessories for use with any icomfort Touch

NOTE: Icomfort Wi-Fi® THERMOSTAT SENSES HUMIDITY &
CONTROLS HUM CONTACTS TO CYCLE HUMIDIFIER BASED

QUIRED.

TIONS. BUILT INTO ALL icomfort by Lennox OUTDOOR UNITS).

®

System

120V CONNECTIONS

“HUM” CONTACT IS
CLOSED ANYTIME
HUMIDITY DEMAND
IS PRESENT

icomfort® ENABLED

FURNACE

sor (Required for

even heat)

Icomfort Wi-Fi
THERMOSTAT

®

RSBus

Maximum total

tions on the RSBus
is limited to 1500ft.

Wire gauge of
RSBus wire is 18.

®

icomfort
ENABLED OUTDOOR AIR
CONDITIONING OR HEAT

PUMP UNIT

ENABLED

®

FURNACE

icomfort

(POWER COMPANY INTERRUPTION SYSTEMS ARE
WIRED SAME AS OVERFLOW SWITCH)

HEPA BYPASS FILTER X2680 HEPA INTERLOCK KIT

NOTE: 24V UV LIGHT
APPLICATIONS

In an icomfort by Lennox
neither furnace nor air handler
transformer will have adequate VA
to power 24V UV light applications.
An additional transformer for UV
light applications is required.

system,

24V HUMIDIFIER CONNECTIONS

CONVENTIONAL NON­COMMUNICATING
SYSTEM

COMMUNICATING SYSTEM

*24V IN jumper not used in non­communicating configuration

icomfort ENABLED

FURNACE

Icomfort Wi-Fi
THERMOSTAT

HVAC
EQUIPMENT

®

DEHUMIDIFIER
CONTROL

Rf WGhGsCf

DH

HVAC EQUIP

CS 7000
THERMOSTAT

*24V IN
JUMPER

ENABLED

®

FURNACE

icomfort

LVCS VENTILATION CONTROL SYSTEM

ENABLED

®

FURNACE

icomfort

TOR COMMON WIRE
THROUGH CURRENT LOOP.

SEE HEPA INTERLOCK KIT
FOR INSTALLATION DETAILS

SEE LVCS VENTILATION
INSTRUCTIONS FOR DAMPER &
SENSOR WIRING

Figure 59

Page 42

STANDARD 1 OR 2 STAGE

AC OR HP UNIT

2 STAGE FURNACE

CUT R-DS
W914

NON-COMMUNICATING
SYSTEM WIRING

DS

R

COMMUNICATING
SYSTEM WIRING

Thermostat

* Not required on all units.

1 Heat / 1 Cool

NOTE - Use DIP
switch 2 to set
second-stage
heat ON delay.
OFF-7 minutes.
ON-12 minutes.

DIP Switch Settings and On-Board Links

DIP Switch 1

Thermostat

Heating

Stages

ON

On Board Links Must Be Cut To Select

System Options

DO NOT CUT ANY
ON-BOARD LINKS

Wiring Connections

S1

T'STAT

FURNACE

TERM. STRIP

OUTDOOR

*

UNIT

1 Heat / 2 Cool

NOTE - Use DIP
switch 2 to set
second-stage
heat ON delay.
OFF-7 minutes.
ON-12 minutes.

1 Heat / 2 Cool
with t'stat with
humidity control

NOTE - Use DIP
switch 2 to set
second-stage
heat ON delay.
OFF-7 minutes.
ON-12 minutes.

ON

ON

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

CUT ON-BOARD LINK

W914

DEHUM

OR

HARMONY

S1

T'STAT

S1

T'STAT

FURNACE

TERM. STRIP

FURNACE

TERM. STRIP

*

o

OUTDOOR

UNIT

OUTDOOR

UNIT

*

Page 43

DIP Switch 1

Thermostat

Thermostat

Heating

Stages

2 Heat / 2 Cool OFF

DIP Switch Settings and On-Board Links

On Board Links Must Be Cut To Select

System Options

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

Wiring Connections

S1

T'STAT

FURNACE

TERM. STRIP

OUTDOOR

*

UNIT

2 Heat / 2 Cool

OFF
with t'stat with
humidity control

2 Heat / 1 Cool

OFF
with t'stat with
humidity control

2 Heat / 1 Cool OFF

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

CUT ON-BOARD LINK

W914

DEHUM

OR

HARMONY

CUT ON-BOARD LINK

W914

DEHUM

OR

HARMONY

S1

T'STAT

S1

T'STAT

S1

T'STAT

FURNACE

TERM. STRIP

FURNACE

TERM. STRIP

FURNACE

TERM. STRIP

o

o

OUTDOOR

UNIT

*

OUTDOOR

UNIT

*

OUTDOOR

UNIT

* Not required on all units.

DO NOT CUT ANY
ON-BOARD LINKS

*

Page 44

Thermostat

Dual Fuel
Single Stage
Heat Pump

ComfortSense
thermostat w/

DIP Switch Settings and On-Board Links

DIP Switch 1

Thermostat

Heating

Stages

OFF

On Board Links Must Be Cut To Select

System Options

CUT ON-BOARD LINK

W951
HEAT

PUMP

T'STAT

H

Wiring Connections

FURNACE

TERM. STRIP

HEAT PUMP

67M41*

bilities
Capable of 2
stage gas heat
control

Dual Fuel
Two Stage
Heat Pump

ComfortSense
thermostat w/

bilities
Capable of 2
stage gas heat
control

OFF

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

CUT ON-BOARD LINK

W951
HEAT
PUMP

L

Y2

D

B

T

T

T'STAT

H

L

Y2

D

B

Y2

FURNACE

TERM. STRIP

67M41*

L

Y

outdoor

sensor

HEAT PUMP

L

Y2

out blue

T

T

outdoor
sensor

* Connect W1 to W1 ONLY if using defrost tempering kit 67M41

NOTE - Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the furnace
integrated control.

Page 45

Thermostat

Dual Fuel
Single Stage
Heat Pump

ComfortSense
thermostat w/

DIP Switch Settings and On-Board Links

DIP Switch 1

Thermostat

Heating

Stages

OFF

On Board Links Must Be Cut To Select

System Options

CUT ON-BOARD LINK

W951
HEAT

PUMP

Wiring Connections

T'STAT

H

FURNACE

TERM. STRIP

HEAT PUMP

67M41*

bilities
Capable of 2
stage gas heat

midification
control

Dual Fuel
Two Stage
Heat Pump

ComfortSense
thermostat w/

bilities
Capable of 2
stage gas heat

midification

OFF

CUT ON-BOARD LINK

W914

DEHUM

OR

HARMONY

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

CUT ON-BOARD LINK

W951
HEAT

PUMP

CUT ON-BOARD LINK

W914

DEHUM

OR

HARMONY

L

Y2

D

B

T

T

T'STAT

H

L

Y2

D

B

Y2

FURNACE

TERM. STRIP

Y2

67M41*

L

Y

outdoor

sensor

HEAT PUMP

L

Y2

out blue

T

T

* Connect W1 to W1 ONLY if using defrost tempering kit 67M41

NOTE - Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the furnace
integrated control.

Page 46

outdoor

sensor

EL296UHV Schematic Wiring Diagram

Figure 60

Page 47

Integrated Control

ACC

7 SEGMENT LED

FLAME SENSE

DIAGNOSTIC

PUSH BUTTON

DIP SWITCHES

OUTDOOR AIR

SENSOR

TERMINALS

DISCHARGE AIR

SENSOR

TERMINALS

TB83

COMMUNICATING

OUTDOOR

EQUIPMENT

TB84

COMMUNICATING

INDOOR

THERMOSTAT

HUM

LINE 1

I +I -CRI +I -

R

C

W1 W2 GY2Y1

NON-COMMUNICATINGNG

24V TERMINALS

CC

RDHLODS

HS/ CAI

INDOOR

BLOWER

CONNECTOR

12 PIN LOW

CONNECTOR

W915 Y1 TO Y2

2 STAGE COMPR

W951 R TO O
HEAT PUMP

W914 R TO DS

DEHUM OR

HARMONY

NEUTRAL

VOLTAGE

RS-BUS LINK (TB82, future use)

I+ = DATA HIGH CONNECTION
I - = DATA LOW CONNECTION

RS-BUS OUTDOOR (TB83)

R = 24VAC
I + = DATA HIGH CONNECTION
I - = DATA LOW CONNECTION
C = 24VAXC COMMON

RS-BUS INDOOR (TB84)

R = 24VAC
I + = DATA HIGH CONNECTION
I - = DATA LOW CONNECTION
C = 24VAXC COMMON

1/4” QUICK CONNECT TERMINALS

HUM = UNPOWERED NORMALLY OPEN (DRY) CONTACTS

XMFR = 120 VAC OUTPUT TO TRANSFORMER

LI = 120 VAC INPUT TO CONTROL

ACC = 120 VAC OUTPUT TO OPTIONAL ACCESSORY

NEUTRALS = 120 VAC NEUTRAL

THERMOSTAT CONNECTIONS (TB1)

DS = DEHUMIDIFICATION SIGNAL
W2 = HEAT DEMAND FROM 2ND STAGE T/STAT

W1 = HEAT DEMAND FROM 1ST STAGE T/STAT
R = CLASS 2 VOLTAGE TO THERMOSTAT

G = MANUAL FAN FROM T'STAT

C = THERMOSTAT SIGNAL GROUND CONNECTED TO
TRANSFORMER GRD (TR) & CHASIS GROUND (GRD)

Y1 = THERMOSTAT 1ST STAGE COOL SIGNAL

Y2 = THERMOSTAT 2ND STAGE COOL SIGNAL

O = THERMOSTAT SIGNAL TO HEAT PUMP

REVERSING VALV E

DH = DEHUMIDIFICATION OUTPUT COMMUNICATING

THERMOSTAT ONLY

L = USE ONLY WITH A COMMUNICATING THERMOSTAT

AND A NON-COMMUNICATING OUTDOOR UNIT

Figure 61

Page 48

Integrated Control DIP Switch Settings -

Conventional Thermostat (non-communicating)

EL296UHV units are equipped with a two-stage, variable
speed integrated control. This control manages ignition
timing, heating mode fan off delays and indoor blower
speeds based on selections made using the control dip
switches and jumpers. The control includes an internal
watchguard feature which automatically resets the ignition
control when it has been locked out. After one hour of con­tinuous thermostat demand for heat, the watchguard will
break and remake thermostat demand to the furnace and
automatically reset the control to relight the furnace.

Note: All icomfort settings are set at the icomfort Wi-Fi®
thermostat. See icomfort installation instruction. In icom­fort communication system all DIP switch and clippable
link settings are ignored. For conventional thermostats
proceed with DIP switch and clippable link settings as out­lined in the following.

Heating Operation DIP Switch Settings
Switch 1 -- Thermostat Selection -- This unit may be

used with either a single-stage or two-stage thermostat.
The thermostat selection is made using a DIP switch
which must be properly positioned for the particular appli­cation. The DIP switch is factory-positioned for use with a
twostage thermostat. If a single-stage thermostat is to be
used, the DIP switch must be repositioned.

a. Select “OFF” for two-stage heating operation controlled by a

two-stage heating thermostat (factory setting);

b. Select “ON” for two-stage heating operation controlled by

a single-stage heating thermostat. This setting provides a
timed delay before second-stage heat is initiated.

Switch 2 -- Second Stage Delay (Used with Single-

Stage Thermostat Only) -- This switch is used to deter­mine the second stage on delay when a single-stage ther­mostat is being used. The switch is factory-set in the OFF

position, which provides a 7-minute delay before second­stage heat is initiated. If the switch is toggled to the ON
position, it will provide a 12-minute delay before second­stage heat is initiated. This switch is only activated when
the thermostat selector jumper is positioned for SINGLE­stage thermostat use.

Switches 3 and 4 -- Blower-Off Delay -- The blower-on
delay of 30 seconds is not adjustable. The blower-off de­lay (time that the blower operates after the heating de-

mand has been satised) can be adjusted by moving

switches 3 and 4 on the integrated control. The unit is
shipped from the factory with a blower-off delay of 90 sec­onds. The blower off delay affects comfort and is adjust­able to satisfy individual applications. Adjust the blower
off delay to achieve a supply air temperature between 90°
and 110°F at the exact moment that the blower is de-en­ergized. Longer off delay settings provide lower supply air
temperatures; shorter settings provide higher supply air
temperatures.Table 12 provides the blower off timings that
will result from different switch settings.

TABLE 11

Blower Off Delay Switch Settings

Blower Off Delay

Seconds

60 On Off

90 (factory) Off Off

120 Off On

180 On On

Switch 3 Switch 4

Indoor Blower Operation DIP Switch Settings
Switches 5 and 6 -- Cooling Mode Blower Speed -- The

unit is shipped from the factory with the dip switches po­sitioned for high speed (4) indoor blower motor operation
during the cooling mode. Table 13 provides the cooling
mode blower speeds that will result from different switch
settings. Switches 5 and 6 set the blower cfm for second­stage cool. The integrated control automatically ramps

down to 70% of the second-stage cfm for rst-stage cfm.

Refer to tables for corresponding cfm values. See Product

Specications for more detailed blower cfm tables.

TABLE 12

Cooling Mode Blower Speeds

Speed Switch 5 Switch 6

Low On On

Medium Low Off On

Medium High On Off

High (factory) Off Off

Switches 7 and 8 -- Cooling Blower Speed Adjustment

-- The unit is shipped from the factory with the dip switches
positioned for NORMAL (no) adjustment. The dip switches
may be positioned to adjust the blower speed by +10% or

-10% to better suit the application. Table 14 below pro­vides blower speed adjustments that will result from dif­ferent switch settings. Refer to tables for corresponding

cfm values. See Product Specications for more detailed

blower cfm tables.

TABLE 13

Cooling Blower Speed Adjustment

Adjustment Switch 7 Switch 8

+10% (approx) On Off

Factory Default Off Off

-10% (approx) Off On

Switches 9 and 10 -- Cooling Mode Blower Speed

Ramping -- Blower speed ramping may be used to en-

hance dehumidication performance. The switches are

factory set at option A which has the greatest effect on
dehumidication performance. Table 15 provides the cool­ing mode blower speed ramping options that will result
from different switch settings. The cooling mode blower
mode blower speed ramping options are detailed on the

next page.

Page 49

NOTE - The off portion of the selected ramp prole also

OFF

applies during heat pump operation in dual fuel applica­tions.

TABLE 14

Cooling Mode Blower Speed Ramping

Ramping Switch 9 Switch 10

A (Factory) Off Off

B Off On

C On Off

D On On

Ramping Option A (Factory Selection)

• Motor runs at 50% for 30 seconds.

• Motor then runs at 82% for approximately 7-1/2
minutes.

• If demand has not been satised after 7-1/2 min-

utes, motor runs at 100% until demand is satised.

• Once demand is met, motor runs at 50% for 30
seconds then ramps down to stop.

1/2 MIN
50% CFM

7 1/2 MIN
82% CFM

COMPRESSOR DEMAND

100%
CFM

1/2 MIN
50% CFM

OFF

Ramping Option B

• Motor runs at 82% for approximately 7-1/2 minutes.

If demand has not been satised after 7-1/2 min­utes, motor runs at 100% until demand is satised.

• Once demand is met, motor ramps down to stop.

Ramping Option D

• Motor runs at 100% until demand is satised.

• Once demand is met, motor ramps down to stop.

100% CFM

COMPRESSOR

DEMAND

OFFOFF

Switches 11, 12 and 13 -- Heating Mode Blower Speed
The switches are factory set to the OFF position which
provides factory default heat speed. Refer to table 16 for
switches 11, 12 and 13 that provided the corresponding
increases or decrease to both high and low heat demand.

TABLE 15

Heating Mode Blower Speeds

Heat Speed Switch 11 Switch 12 Switch 13

Increase 24% On On On

Increase 18% On On Off

Increase 12% On Off On

Increae 6% On Off Off

Factory

Off Off Off

Default

Decrease 6% Off Off On

Decrease

Off On Off

12%

Decrease

Off On On

18%

Switches 14 and 15 -- Continuous Blower Speed --

Table 17 provides continuous blower speed adjustments
that will result from different switch settings.

OFF

7 1/2 MIN

82%CFM

COMPRESSOR DEMAND

100% CFM

Ramping Option C

• Motor runs at 100% until demand is satised.

• Once demand is met, motor runs at 100% for 45

seconds then ramps down to stop.

100% CFM

COMPRESSOR

DEMAND

100% CFM

45 SEC.

OFF

OFF

Page 50

TABLE 16

Continuous Blower Speed

Coninuous Blower Speed Switch 14 Switch 15

28% of High Cool Speed Off On

38% of High Cool Speed

(Factory)

70% of High Cool Speed On Off

100% of High Cool Speed On On

Off Off

Blower Data

EL296UH045XV36B BLOWER PERFORMANCE (less lter)

BOTTOM RETURN AIR
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

1

Heating Speed

DIP Switch

Settings

+24% 915 1125

+18% 865 1085

+12% 805 1040

+6% 780 985

Factory Default 740 925

–6% 665 875

–12% 630 800

–18% 585 735

1

Cooling Speed

DIP Switch

Settings

Low Medium-Low Medium-High

+ 595 760 865 980 905 1075 1210 1370

Factory Default 540 660 785 890 815 980 1120 1255

– 485 600 695 790 720 885 1020 1135

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

COOLING

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

2

High Low Medium-Low Medium-High

2

High

EL296UH070XV36B BLOWER PERFORMANCE (less lter)

BOTTOM RETURN AIR
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

1

Heating Speed

DIP Switch

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

Settings

+24% 1095 1220

+18% 1035 1170

+12% 985 1120

+6% 915 1055

Factory Default 850 995

–6% 835 915

–12% 755 845

–18% 695 810

COOLING

1

Cooling Speed

DIP Switch

Settings

Low Medium-Low Medium-High

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

2

High Low Medium-Low Medium-High

2

High

+ 600 740 840 970 860 1060 1215 1365

Factory Default 555 665 770 855 810 960 1130 1265

– 500 600 680 790 705 840 1005 1140

1

Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch Settings.

2

Factory default setting.

NOTES - The effect of static pressure is included in air volumes shown.

First stage HEAT is approximately 91% of the same second stage HEAT.
First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position.
Continuous Fan Only speed is selectable at 28%, 38%, 70% and 100% of the selected second stage cooling speed - minimum 250 cfm.
Lennox iHarmony® Zoning System Applications - Minimum blower speed is 250 cfm.

Page 51

Blower Data

EL296UH090XV36C BLOWER PERFORMANCE (less lter)

BOTTOM RETURN AIR
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

1

Heating Speed

DIP Switch

Settings

+24% 1215 1300

+18% 1140 1240

+12% 1100 1170

+6% 1020 111 5

Factory Default 965 1070

–6% 915 970

–12% 850 925

–18% 805 855

1

Cooling Speed

DIP Switch

Settings

Low Medium-Low Medium-High

+ 625 710 830 950 875 1040 1210 1360

Factory Default 565 670 760 860 800 945 1100 1245

– 520 610 685 785 720 840 970 111 5

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

COOLING

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

2

High Low Medium-Low Medium-High

2

High

EL296UH110XV48C BLOWER PERFORMANCE (less lter)

BOTTOM RETURN AIR
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

1

Heating Speed

DIP Switch

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

Settings

+24% 1470 1605

+18% 1450 1495

+12% 1385 1445

+6% 1295 1385

Factory Default 1225 1305

–6% 1160 1225

–12% 1090 1150

–18% 1035 1070

COOLING

1

Cooling Speed

DIP Switch

Settings

Low Medium-Low Medium-High

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

2

High Low Medium-Low Medium-High

2

High

+ 810 980 1085 1235 1100 1325 1530 1760

Factory Default 760 875 1010 1135 1025 1205 1405 1565

– 695 805 905 1040 920 1080 1260 1440

1

Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch Settings.

2

Factory default setting.

NOTES - The effect of static pressure is included in air volumes shown.

First stage HEAT is approximately 91% of the same second stage HEAT.
First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position.
Continuous Fan Only speed is selectable at 28%, 38%, 70% and 100% of the selected second stage cooling speed - minimum 380 cfm.
Lennox iHarmony® Zoning System Applications - Minimum blower speed is 250 cfm for EL296UH090XV60C and 380 cfm for EL296UH110XV48C.

Page 52

Blower Data

EL296UH090XV60C BLOWER PERFORMANCE (less lter)

BOTTOM RETURN AIR
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

1

Heating Speed

DIP Switch

Settings

+24% 1490 1985

+18% 1435 1915

+12% 1335 1805

+6% 1280 1645

Factory Default 1185 1625

–6% 1095 1530

–12% 990 1450

–18% 900 1345

1

Cooling Speed

DIP Switch

Settings

Low Medium-Low Medium-High

+ 1050 1270 1445 1620 1590 1815 2010 2195

Factory Default 975 1120 1295 1460 1460 1645 1845 2010

– 865 1010 1120 1290 1320 1500 1645 1860

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

COOLING

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

2

High Low Medium-Low Medium-High

2

High

EL296UH110XV48C BLOWER PERFORMANCE (less lter)

BOTTOM RETURN AIR
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

1

Heating Speed

DIP Switch

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

Settings

+24% 1470 1605

+18% 1450 1495

+12% 1385 1445

+6% 1295 1385

Factory Default 1225 1305

–6% 1160 1225

–12% 1090 1150

–18% 1035 1070

COOLING

1

Cooling Speed

DIP Switch

Settings

Low Medium-Low Medium-High

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

2

High Low Medium-Low Medium-High

2

High

+ 810 980 1085 1235 1100 1325 1530 1760

Factory Default 760 875 1010 1135 1025 1205 1405 1565

– 695 805 905 1040 920 1080 1260 1440

1

Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch Settings.

2

Factory default setting.

NOTES - The effect of static pressure is included in air volumes shown.

First stage HEAT is approximately 91% of the same second stage HEAT.
First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position.
Continuous Fan Only speed is selectable at 28%, 38%, 70% and 100% of the selected second stage cooling speed - minimum 380 cfm.
Lennox iHarmony® Zoning System Applications - Minimum blower speed is 450 cfm. for EL296UH090XV60C and 380 cfm for EL296UH110XV48C

Page 53

Blower Data

EL296UH110XV60C BLOWER PERFORMANCE (less lter)

BOTTOM RETURN AIR
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

1

Heating Speed

DIP Switch

Settings

+24% 1385 1965

+18% 1475 1880

+12% 1355 1790

+6% 1370 1725

Factory Default 1200 1630

–6% 1140 1550

–12% 1070 1460

–18% 980 1345

1

Cooling Speed

DIP Switch

Settings

Low Medium-Low Medium-High

+ 1060 1245 1345 1545 1560 1740 1930 2125

Factory Default 970 1145 1265 1395 1405 1565 1775 1945

– 885 1025 1110 1250 1270 1425 1610 1770

1

Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch Settings.

2

Factory default setting.

NOTES - The effect of static pressure is included in air volumes shown.

First stage HEAT is approximately 91% of the same second stage HEAT.
First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position.
Continuous Fan Only speed is selectable at 28%, 38%, 70% and 100% of the selected second stage cooling speed - minimum 450 cfm.
Lennox iHarmony® Zoning System Applications - Minimum blower speed is 450 cfm.

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

COOLING

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

2

High Low Medium-Low Medium-High

2

High

Page 54

On-Board Links

Note: In icomfort systems with a conventional outdoor unit
(non-communicating), the on-board clippable links must
be set to properly congure the system.

WARNING

Carefully review all conguration information provided.

Failure to properly set DIP switches, jumpers and on­board links can result in improper operation!

Refer to table 18 for operation sequence in applications
including EL296UHV, a thermostat which features humid­ity control and a single-speed outdoor unit. Table 19 gives
the operation sequence in applications with a two-speed
outdoor unit.

On-Board Link W951 Heat Pump (R to O)

On-board link W951 is a clippable connection between
terminals R and O on the integrated control. W951 must
be cut when the furnace is installed in applications which
include a heat pump unit and a thermostat which features

On-Board Link W914 Dehum or Harmony (R to DS)

On-Board Link W914 Dehum or Harmony (R to DS) On­board link W914, is a clippable connection between termi­nals R and DS on the integrated control. W914 must be
cut when the furnace is installed with either the Harmony
III zone control or a thermostat which features humidity
control. If the link is left intact the PMW signal from the
Harmony III control will be blocked and also lead to control
damage

dual fuel use. If the link is left intact, terminal “O” will re­main energized eliminating the HEAT MODE in the heat
pump.

On-Board Link W915 2 Stage Compr (Y1 to Y2)

On-board link W915 is a clippable connection between
terminals Y1 and Y2 on the integrated control. W915 must
be cut if two-stage cooling will be used. If the Y1 to Y2 link
is not cut the outdoor unit will operate in second-stage
cooling only.

TABLE 17

OPERATING SEQUENCE

EL296UHV, Non-Communicating Thermostat with Humidity Control Feature and Single-Speed Outdoor Unit

OPERATING SEQUENCE SYSTEM DEMAND SYSTEM RESPONSE

System

Condition

NO CALL FOR DEHUMIDIFICATION

Normal Operation 1 On On On Acceptable

BASIC MODE (only active on a Y1 thermostat demand)

Normal Operation 1 On On On Acceptable

Dehumidication

call

PRECISION MODE (operates independent of a Y1 demand)

Normal Operation 1 On On On Acceptable

Dehumidication

Call

Dehumidication

Call Only

Dave Lennox ComfortSense® 7000 thermostat to use for this application - Y2081 4 heat / 2 cool

*Dehumidication blower speed is 70% of COOL speed for all units .

**In Precision mode, ComfortSense® 7000 thermostat will maintain room temperature up to 2 °F (1.2°C) cooler than room setting.

Step

2 On On On Demand 0 VAC High 70%

2 On On On Demand 0 VAC High 70%

1 On On On Demand 0 VAC High 70%

Jumpers at indoor unit with a single stage outdoor unit. With Condensing unit - Cut
W914 (R to DS) on SureLight® control With Heat Pump - Cut W914 (R to DS) &
W951 (R to O) on SureLight® control

Thermostat Demand Relative Humidity

Y1 O G W1 Status D

24

VAC

24

VAC

24

VAC

Compre

ssor

High 100%

High 100%

High 100%

Blower

CFM

(cool)

Comments

Compressor and
indoor blower follow
thermostat demand

ComfortSense® 7500

thermostat energizes

Y1 and de-energizes

D on a call for de-

humidication

Dehumidication

mode begins when

humidity is greater

than set point

ComfortSense®
7500 thermostat will
try to maintain room
humidity setpoint by

allowing the room
space to maintain

a cooler room

thermostat setpoint**

Page 55

TABLE 18

OPERATING SEQUENCE

SL280UHV, Non-Communicating Thermostat with Humidity Control Feature and Two-Speed Outdoor Unit

OPERATING

SEQUENCE

System

Condition

Step

NO CALL FOR DEHUMIDIFICATION

Normal Operation

Y1

Normal Operation

Y2

1 On On On Acceptable

2 On On On On Acceptable

ROOM THERMOSTAT CALLS FOR FIRST STAGE COOLING

BASIC MODE (only active on a Y1 thermostat demand)

Normal Operation 1 On On On Acceptable

Dehumidication

call

2 On On On On Demand

PRECISION MODE (operates independent of a Y1 demand)

Normal Operation 1 On On On Acceptable

Dehumidication

Call

Dehumidication

Call Only

2 On On On On Demand

1 On On On On Demand

ROOM THERMOSTAT CALLS FOR FIRST AND SECOND STAGE COOLING

BASIC MODE (only active on a Y1 thermostat demand)

Normal Operation 1 On On On On Acceptable

Dehumidication

Call

2 On On On On Demand

PRECISION MODE (operates independent of a Y1 thermostat demand)

Normal Operation 1 On On On Acceptable

Dehumidication

Call

Dehumidication

Call ONLY

2 On On On On Demand

1 On On On On Demand

Jumpers at indoor unit with a two stage outdoor unit

Cut factory jumper from Y1 to Y2 or cut W915 (Y1 to Y2)

With Condensing unit - Cut W914 (R to DS) on SureLight® control

With Heat Pump - Cut W914 (R to DS) & W951 (R to O) on SureLight® control

Dave Lennox ComfortSense® 7000 thermostat to use for this application - Y2081 4 heat / 2 cool

*Normal operation rst stage cooling blower speed is 70% COOL speed.

**Dehumidication blower speed is, reduced to 70% of COOL.

***In Precision mode, ComfortSense® 7000 thermostat will maintain room temperature up to 2 °F (1.2°C) cooler than room setting.

SYSTEM DEMAND SYSTEM RESPONSE

Thermostat Demand Relative Humidity

Y1 Y2 O G W1 W2 Status D

24

VAC

24

VAC

24

VAC

0

VAC

24

VAC

0

VAC

0

VAC

24

VAC

0

VAC

24

VAC

0

VAC

0

VAC

Compre

ssor

Low 70%

High 100%

Low 70%

High 70%

Low 70%

High 70%

High 70%

High 100%

High 70%

Low 70%

High 70%

High 70%

Blower

CFM

(cool)

Comments

Compressor and indoor
blower follow thermostat
demand

ComfortSense® 7500
thermostat energizes Y1
and de-energizes D on a

call for de-humidication

Dehumidication mode

begins when humidity is
greater than set point

ComfortSense® 7500
thermostat will try to
maintain room humidity
setpoint by allowing the
room space to maintain
a cooler room thermostat
setpoint**

ComfortSense® 7500
thermostat energizes Y2
and de-energizes D on a

call for de-humidication

Dehumidication mode

begins when humidity is
greater than set point

ComfortSense® 7500
thermostat will try to
maintain room humidity
setpoint by allowing the
room space to maintain
a cooler room thermostat
setpoint***

Page 56

Unit Start Up

FOR YOUR SAFETY READ BEFORE OPERATING

WARNING

Do not use this furnace if any part has been underwater.

A ood-damaged furnace is extremely dangerous.
Attempts to use the furnace can result in re or explosion.
Immediately call a qualied service technician to inspect

the furnace and to replace all gas controls, control
system parts, and electrical parts that have been wet or
to replace the furnace, if deemed necessary.

WARNING

Danger of explosion. Can cause injury or
product or property damage. If overheating
occurs or if gas supply fails to shut off, shut
off the manual gas valve to the appliance
before shutting off electrical supply.

CAUTION

Before attempting to perform any service or maintenance,
turn the electrical power to unit OFF at disconnect switch.

BEFORE LIGHTING the unit, smell all around the furnace

area for gas. Be sure to smell next to the oor because
some gas is heavier than air and will settle on the oor.

The gas valve on the EL296UHV is equipped with a gas
control switch (lever). Use only your hand to moveswitch.
Never use tools. If the the switch will not move by hand,
do not try to repair it. Force or attempted repair may result

in a re or explosion.

Placing the furnace into operation:

EL296UHV units are equipped with an automatic hot
surface ignition system. Do not attempt to manually light
burners on this furnace. Each time the thermostat calls for
heat, the burners will automatically light. The ignitor does
not get hot when there is no call for heat on these units.

Priming Condensate Trap

The condensate trap should be primed with water prior
to start-up to ensure proper condensate drainage. Either

pour 10 . oz. (300 ml) of water into the trap, or follow

these steps to prime the trap:

1 - Follow the lighting instructions to place the unit into

operation.
2 - Set the thermostat to initiate a heating demand.
3 - Allow the burners to re for approximately 3 minutes.
4 - Adjust the thermostat to deactivate the heating

demand.

5 - Wait for the combustion air inducer to stop. Set the

thermostat to initiate a heating demand and again

allow the burners to re for approximately 3 minutes.

6 - Adjust the thermostat to deactivate the heating

demand and wait for the combustion air inducer to
stop. At this point, the trap should be primed with

sufcient water to ensure proper condensate drain

operation.

WARNING

If you do not follow these instructions exactly, a re or

explosion may result causing property damage, personal
injury or death.

Gas Valve Operation (Figure 62)

1 - STOP! Read the safety information at the beginning

of this section.
2 - Set the thermostat to the lowest setting.
3 - Turn off all electrical power to the unit.
4 - This furnace is equipped with an ignition device

which automatically lights the burners. Do not try to

light the burners by hand.
5 - Remove the access panel.
6 - Move gas valve switch to OFF. See gure 62.
7 - Wait ve minutes to clear out any gas. If you then

smell gas, STOP! Immediately call your gas supplier

from a neighbor’s phone. Follow the gas supplier’s

instructions. If you do not smell gas go to next step.
8 - Move gas valve switch to ON. See Figure 62.

WHITE RODGERS GAS VALVE

INLET PRESSURE POST

GAS VALV E SHOWN IN ON POSITION

9 - Replace the access panel.
10 - Turn on all electrical power to to the unit.
11 - Set the thermostat to desired setting.

NOTE - When unit is initially started, steps 1 through
11 may need to be repeated to purge air from gas
line.

12 - If the appliance will not operate, follow the

instructions “Turning Off Gas to Unit” and call your

service technician or gas supplier.

Turning Off Gas to Unit

1 - Set the thermostat to the lowest setting.
2 - Turn off all electrical power to the unit if service is to

be performed.
3 - Remove the access panel.

MANIFOLD

PRESSURE TAP

Figure 62

HIGH FIRE ADJUSTMENT

SCREW

(under cap)

Page 57

4 - Move gas valve switch to OFF.
5 - Replace the access panel.

Failure To Operate

If the unit fails to operate, check the following:

1 - Is the thermostat calling for heat?
2 - Are access panels securely in place?
3 - Is the main disconnect switch closed?
4 - Is there a blown fuse or tripped breaker?
5 - Is the lter dirty or plugged? Dirty or plugged lters

will cause the limit control to shut the unit off.
6 - Is gas turned on at the meter?
7 - Is the manual main shut-off valve open?
8 - Is the internal manual shut-off valve open?
9 - Is the unit ignition system in lockout? If the unit

locks out again, inspect the unit for blockages.

Heating Sequence Of Operation

1 - When thermostat calls for heat, combustion air

inducer starts.

2 - Combustion air pressure switch proves blower

operation. Switch is factory set and requires no

adjustment.
3 - After a 15-second prepurge, the hot surface ignitor

energizes.
4 - After a 20-second ignitor warm-up period, the gas

valve solenoid opens. A 4-second trial for ignition

period begins.”
5 - Gas is ignited, ame sensor proves the ame, and

the combustion process continues.
6 - If ame is not detected after rst ignition trial,

the ignition control will repeat steps 3 and 4 four

more times before locking out the gas valve

(“WATCHGUARD” ame failure mode). The ignition

control will then automatically repeat steps 1 through

6 after 60 minutes. To interrupt the 60-minute

“WATCHGUARD” period, move thermostat from

“Heat” to “OFF” then back to “Heat”. Heating

sequence then restarts at step 1.

Gas Pressure Adjustment

Gas Flow (Approximate)

TABLE 19

GAS METER CLOCKING CHART

Seconds for One Revolution

EL296

Unit

-045 80 160 200 400

-070 55 110 136 272

-090 41 82 102 204

-110 33 66 82 164

-135 27 54 68 136

Natural-1000 btu/cu ft LP-2500 btu/cu ft

Natural LP

1 cu ft

Dial

2 cu ft

Dial

1 cu ft

Dial

2 cu ft

Dial

Furnace should operate at least 5 minutes before check­ing gas ow. Determine time in seconds for two revolu­tions of gas through the meter. (Two revolutions assures
a more accurate time.) Divide by two and compare to time
in table 20. If manifold pressure matches table 22 and rate
is incorrect, check gas orices for proper size and restric­tion. Remove temporary gas meter if installed.

NOTE - To obtain accurate reading, shut off all other gas
appliances connected to meter.

Supply Pressure Measurement

An inlet post located on the gas valve provides access
to the supply pressure. See Figure 62. Back out the 3/32
hex screw one turn, connect a piece of 5/16 tubing and
connect to a manometer to measure supply pressure. See
table 22 for supply line pressure.

On multiple unit installations, each unit should be checked
separately, with and without units operating. Supply pres­sure must fall within range listed in table 22.

Manifold Pressure Measurement

NOTE - Pressure test adapter kit (10L34) is available from
Lennox to facilitate manifold pressure measurement.

A manifold pressure post located on the gas valve pro­vides access to the manifold pressure. See Figure 62.
Back out the 3/32 hex screw one turn, connect a piece
of 5/16 tubing and connect to a manometer to measure
manifold pressure.

To correctly measure manifold pressure, the differential
pressure between the positive gas manifold and the neg­ative burner box must be considered.

1 - Connect the test gauge positive side “+“ to manifold

pressure tap on gas valve as noted above.

2 - Tee into the gas valve regulator vent hose and

connect to test gauge negative “-”.

3 - Ignite unit on low re and let run for 5 minutes to

allow for steady state conditions.

4 - After allowing unit to stabilize for 5 minutes, record

manifold pressure and compare to value given in
table 22.

5 - If necessary, make adjustments. Figure 62 shows

location of high re and low re adjustment screws.

6 - Repeat steps 3, 4 and 5 on high re. See values in

table 22.

7 - Shut unit off and remove manometer as soon as

an accurate reading has been obtained. Turn the
supply and manifold 3/32” hex screws one revolution
back into the gas valve.

8 - Start unit and perform leak check. Seal leaks if

found.

Page 58

Proper Cumbustion

Furnace should operate minimum 15 minutes with correct

manifold pressure and gas ow rate before checking com­bustion. Take combustion sample beyond the ue outlet

and compare to the tables below.

TABLE 20

EL296

Model

CO2% For Nat CO2% For L.P

Low Fire High Fire Low Fire High Fire

045 5.4 - 6.4 7.5 - 8.5 6.4 - 7.4 8.8 - 9.8

070 5.3 - 6.3 7.4 - 8.4 6.3 - 7.3 8.7 - 9.7

090 5.8 - 6.8 7.6 - 8.6 6.8 - 7.8 8.9 - 9.9

High Altitude

NOTE - In Canada, certication for installations at eleva­tions over 4500 feet (1372 m) is the jurisdiction of local
authorities.

Units may be installed at altitudes up to 10,000 ft. above
sea level. See table 22 for de-rate manifold values. Units

installed at altitude of 7501 - 10,000 feet require an orice

change. Units installed at altitude of 4501 - 10,000 feet
require a pressure switch change which can be ordered
separately. Table 23 lists conversion kit and pressure
switch requirements at varying altitudes.

The combustion air pressure switch is factory-set and re­quiresno adjustment.

110 6.1 - 7.1 8.0 - 9.0 7.1 - 8.1 9.3 - 10.3

135 6.1 - 7.1 7.8 - 8.8 7.1 - 8.2 9.1 - 10.1

The maximum carbon monoxide reading should not exceed 100ppm.

TABLE 21

Manifold and Supply Line Pressure 0-10,000ft.

Manifold Pressure in. wg. Supply Line

Unit Gas

Natuarl 1.7 3.5 1.6 3.3 1.5 3.2 1.5 3.1 1.7 3.5 4.5 13.0

All

Sizes

NOTE - A natural to L.P. propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation instruction
for the conversion procedure.

LP/

Propane

0 - 4500 ft 4501 - 5500 ft. 5501 - 6500 ft 6501 - 7500 ft 7501 - 10,000 ft

Low
Fire

4.9 10.0 4.6 9.4 4.4 9.1 4.3 8.9 4.9 10.0 11.0 13.0

High

Fire

Low

Fire

High

Fire

Low
Fire

High

Fire

Low

Fire

High

Fire

Low

Fire

High

Fire

Pressure in. w.g

0 - 10,000 ft.

Min Max

TABLE 22

LP/Propane Conversion Kit and Pressure Switch Requirements at Varying Altitudes

Natural to

Unit

045

070 14A54 14A53

090 14A57 14A54

110 14A46 14A51

135 14A49 14A51

* Conversion requires installation of a gas valve manifold spring which is provided with the gas conversion kit. Pressure switch is factory
set. No adjustment necessary. All models use the factory-installed pressure switch from 0-4500 feet (0-1370 m).

LP/Propane

0 - 7500 ft 7501 - 10,000 ft 7501 - 10,000 ft 4501 - 7500 ft 7501 - 10,000 ft

*11K51 73W37 *11K46

High Altitude

Natural Burner

Orice Kit

High Altitude LP/

Propane Burner

Orice Kit

High Altitude Pressure Switch

14A47 14A50

Page 59

Testing for Proper Venting and Sufcient Combustion Air for Non-Direct Vent Applications

8 - If improper venting is observed during any of the

WARNING

CARBON MONOXIDE POISONING HAZARD!

Failure to follow the steps outlined below for each
appliance connected to the venting system being placed
into operation could result in carbon monoxide poisoning
or death.

The following steps shall be followed for each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation.

After the EL296UHV gas furnace has been started, the
following test should be conducted to ensure proper vent-

ing and sufcient combustion air has been provided to the
EL296UHV as well as to other gas-red appliances which

are separately vented.
If a EL296UHV furnace replaces a Category I furnace

which was commonly vented with another gas appliance,
the size of the existing vent pipe for that gas appliance
must be checked. Without the heat of the original furnace

ue products, the existing vent pipe is probably oversized

for the single water heater or other appliance. The vent
should be checked for proper draw with the remaining ap­pliance.

The test should be conducted while all appliances (both
in operation and those not in operation) are connected to
the venting system being tested. If the venting system has
been installed improperly, or if provisions have not been

made for sufcient amounts of combustion air, corrections

must be made as outlined in the previous section.

1 - Seal any unused openings in the venting system.
2 - Visually inspect the venting system for proper

size and horizontal pitch. Determine there is no

blockage or restriction, leakage, corrosion, or other

deciencies which could cause an unsafe condition.

3 - To the extent that it is practical, close all building

doors and windows and all doors between the

space in which the appliances connected to the

venting system are located and other spaces of the

building.
4 - Close replace dampers.
5 - Turn on clothes dryers and any appliances not

connected to the venting system. Turn on any

exhaust fans, such as range hoods and bathroom

exhausts, so they will operate at maximum speed.

Do not operate a summer exhaust fan.
6 - Follow the lighting instruction to place the appliance

being inspected into operation. Adjust thermostat

so appliance will operate continuously.
7 - Use the ame of match or candle to test for spillage

of ue gases at the draft hood relief opening after 5

minutes of main burner operation.

above tests, the venting system must be corrected

or sufcient combustion/make-up air must be

provided. The venting system should be re-sized
to approach the minimum size as determined by
using the appropriate tables in appendix G in the
current standards of the National Fuel Gas Code
ANSI-Z223.1/NPFA 54 in the U.S.A., and the
appropriate Natural Gas and Propane appliances
venting sizing tables in the current standard of the
CSA-B149 Natural Gas and Propane Installation
Codes in Canada.

9 - After determining that each appliance remaining

connected to the common venting system properly
vents when tested as indicated in step 3, return

doors, windows, exhaust fans, replace dampers

and any other gas-burning appliance to their
previous condition of use.

Repair Parts

The following repair parts are available through Lennox
dealers. When ordering parts, include the complete fur­nace model number listed on the CSA nameplate -- Ex­ample: EL296UHV045P24B-01. All service must be per­formed by a licensed professional installer (or equivalent),
service agency, or gas supplier.

Cabinet Parts

Outer access panel
Blower access panel
Top Cap

Control Panel Parts

Transformer
Integrated control board
Door interlock switch

Blower Parts

Blower wheel
Motor
Motor mounting frame
Motor capacitor
Blower housing cutoff plate

Heating Parts

Flame Sensor
Heat exchanger assembly
Gas manifold
Combustion air inducer
Gas valve
Main burner cluster

Main burner orices

Pressure switch
Ignitor
Primary limit control
Flame rollout switches

Page 60

Other Unit Adjustments

NOTE - See troubleshooting ow charts if any safety

switches are found to be open.

Primary Limit.

The primary limit is located on the heating compartment
vestibule panel. This limit is factory set and requires no
adjustment.

Flame Rollout Switches (Two)

These manually reset switches are located on the front of
the burner box.

Pressure Switch

The pressure switch is located in the heating compartment
on the cold end header box. This switch checks for proper
combustion air inducer operation before allowing ignition
trial. The switch is factory-set and must not be adjusted.

Temperature Rise

Place the unit into operation with a second-stage heating
demand. After supply and return air temperatures have
stabilized, check the temperature rise. If necessary, adjust
the heating blower speed to maintain the temperature rise
within the range shown on the unit nameplate. Increase
the blower speed to decrease the temperature rise. De­crease the blower speed to increase the temperature rise.
Failure to properly adjust the temperature rise may cause
erratic limit operation.

Electrical

1 - Check all wiring for loose connections.
2 - Check for the correct voltage at the furnace (furnace

operating). Correct voltage is 120VAC + 10%
3 - Check amp-draw on the blower motor with blower

access panel in place.

Unit Nameplate__________Actual__________

Exhaust and Air Intake Pipe

1 - Check exhaust and air intake connections for

tightness and to make sure there is no blockage.

2 - Is pressure switch closed? Obstructed exhaust pipe

will cause unit to shut off at pressure switch. Check

termination for blockages.
3 - Obstructed pipe or termination may cause rollout

switches to open. Reset manual ame rollout

switches on burner box assembly if necessary.

Heating Sequence of Operation

Electronic Ignition

The two-stage, variable speed integrated control used in
EL296UHV units has an added feature of an internal

Watchguard control. The feature serves as an automatic
reset device for ignition control lockout caused by ignition
failure. After one hour of continuous thermostat demand
for heat, the Watchguard will break and remake thermo­stat demand to the furnace and automatically reset the
control to begin the ignition sequence.

NOTE - The ignition control thermostat selection DIP
switch is factory-set in the “TWO-STAGE” position.

Applications Using a Two-Stage Thermostat

See Figure 63 for ignition control sequence

A - Heating Sequence -- Integrated Control Thermostat

Selection DIP Switch 1 OFF in “Two-Stage” Position

(Factory Setting)

1 - On a call for heat, thermostat rst-stage contacts

close sending a signal to the integrated control. The
integrated control runs a self-diagnostic program
and checks high temperature limit switches for
normally closed contacts and pressure switches for
normally open contacts. The combustion air inducer
is energized at low speed.

2 - Once the control receives a signal that the low

pressure switch has closed, the combustion air
inducer begins a 15-second pre-purge in low speed.

NOTE - If the low re pressure switch does not close
the combustion air inducer will switch to high re.
After a 15 second pre-purge the high re pressure
switch will close and the unit will begin operation on
high re. After 10 to 20 seconds of high re opera­tion the unit will switch to low re..

3 - After the pre-purge is complete, a 20-second initial

ignitor warm-up period begins. The combustion air
inducer continues to operate at low speed.

4 - After the 20-second warm-up period has ended,

the gas valve is energized on low re (rst stage)

and ignition occurs. At the same time, the control
module sends a signal to begin an indoor blower
30-second ON-delay. When the delay ends, the

indoor blower motor is energized on the low re

heating speed, the HUM contacts close energizing

the humidier and 120V ACC terminal is energized.

The furnace will continue this operation as long as

the thermostat has a rst-stage heating demand.

5 - If second-stage heat is required, the thermostat

second- stage heat contacts close and send a signal
to the integrated control. The integrated control
initiates a 30-second second-stage recognition

delay.

6 - At the end of the recognition delay, the integrated

control energizes the combustion air inducer at

high speed. The control also checks the high re

(second stage) pressure switch to make sure it is

closed. The high re (second stage) gas valve is

energized and the indoor blower motor is energized

for operation at the high re heating speed.

7 - When the demand for high re (second stage) heat

is satised, the combustion air inducer is switched
to the low-re heating speed and the high-re

(second stage) gas valve is de-energized. The

low-re (rst stage) gas valve continues operation.
The indoor blower motor is switched to the low-re

heating speed.

8 - When the thermostat demand for low-re (rst

stage) heat is satised, the gas valve is de­energized and the eld-selected indoor blower off

delay begins. The combustion air inducer begins a
5-second post-purge period.

9 - When the combustion air post-purge period is

complete, the inducer and the HUM contacts are
de-energized. The indoor blower is de-energized at
the end of the off delay as well as the 120V ACC
terminals.

Page 61

Applications Using A Single-Stage Thermostat

HEATING OPERATION WITH SINGLE STAGE THERMOSTAT

r

See Figure 64 for ignition control sequence

B - Heating Sequence -- Integrated Control Thermostat

Selection DIP Switch 1 ON in “Single-Stage” Position

NOTE - In these applications, two-stage heat will be initi­ated by the integrated control if heating demand has not
been satised after the eld adjustable period (7 or 12
minutes).

1 - On a call for heat, thermostat rst-stage contacts

close sending a signal to the integrated control. The
integrated control runs a self-diagnostic program
and checks high temperature limit switches for
normally closed contacts and pressure switches for
normally open contacts. The combustion air inducer
is energized at low speed.

2 - Once the control receives a signal that the low

pressure switch has closed, the combustion air

inducer begins a 15-second pre-purge in low speed.

NOTE - If the low re pressure switch does not close
the combustion air inducer will switch to high re.
After a 15 second pre-purge the high re pressure
switch will close and the unit will begin operation on
high re. After 10 to 20 seconds of high re opera­tion the unit will switch to low re.

3 - After the pre-purge is complete, a 20-second initial

ignitor warm-up period begins. The combustion air

inducer continues to operate at low speed.

4 - After the 20-second warm-up period has ended,

the gas valve is energized on low re (rst stage)

and ignition occurs. At the same time, the control
module sends a signal to begin an indoor blower
30-second ON-delay. When the delay ends, the

indoor blower motor is energized on the low re

heating speed and the HUM contacts are energized.
The integrated control also initiates a second-stage
on delay (factory-set at 7 minutes; adjustable to 12
minutes).

5 - If the heating demand continues beyond the

secondstage on delay, the integrated control
energizes the combustion air inducer at high speed.

The control also checks the high re (second stage)

pressure switch to make sure it is closed. The high

re (second stage) gas valve is energized and the

indoor blower motor is energized for operation at

the high re heating speed.

6 - When the thermostat heating demand is satised,

the combustion air inducer begins a 5-second low

speed post-purge. The eld-selected indoor blower

off delay begins. The indoor blower operates at the

low-re heating speed.

7 - When the combustion air post-purge period is

complete, the inducer and the HUM contacts are
de-energized. The indoor blower is de-energized at
the end of the off delay as well as the 120V ACC
terminals.

HEATING OPERATION WITH TWO-STAGE THERMOSTAT

15

Pre-Purge

Ignitor Warm-up

35

30 seconds

39

30* second

Trial For
Ignition

RECOGNITION PERIOD

blower

“on” delay

ON

1 stg heat demand
low speed CAI

ignitor
low fire gas valve

indoor blower low heat

2 stg heat demand
high speed CAI
high fire gas valve
indoor blower high heat

OFF

* Conventional thermostat 30 seconds, icomfort Touch® thermostat set for 30 adjustable 15 to 45 seconds.

1

Figure 63

ON

OFF

heat demand
low speed CAI
ignitor
low fire gas valve

indoor blower low heat

7 or 12 minutes after heating demand begins, furnace switches to high fire (depends on setting)

high speed CAI
high fire gas valve

indoor blower high heat

* Conventional thermostat 30 seconds, icomfort Touch

1

Pre-Purge

15

Ignitor Warm-up

35

39

Trial For
Ignition

30* second

blower

“on” delay

®

thermostat set for 30 adjustable 15 to 45 seconds.

80

5 SEC80

Post

Purge

blower

delay

5 SEC

Post

Purge

“off”

blowe

“off”

delay

Figure 64

Page 62

Service

WARNING

ELECTRICAL SHOCK, FIRE,

OR EXPLOSION HAZARD.

Failure to follow safety warnings exactly could result in
dangerous operation, serious injury, death or property
damage.

Improper servicing could result in dangerous operation,
serious injury, death, or property damage. Before
servicing, disconnect all electrical power to furnace.

When servicing controls, label all wires prior to
disconnecting. Take care to reconnect wires correctly.
Verify proper operation after servicing.

WARNING

The blower access panel must be securely in place when
the blower and burners are operating. Gas fumes, which
could contain carbon monoxide, can be drawn into living
space resulting in personal injury or death.

Annual Furnace Maintenance

At the beginning of each heating season, and to comply
with the Lennox Limited Warranty, your system should
be checked as follows:

1 - Check wiring for loose connections, voltage at

indoor unit and amperage of indoor motor.

2 - Check the condition of the belt and shaft bearings

if applicable.
3 - Inspect all gas pipe and connections for leaks.
4 - Check the cleanliness of lters and change if

necessary (monthly).
5 - Check the condition and cleanliness of burners and

heat exchanger and clean if necessary.
6 - Check the cleanliness of blower assembly and

clean the housing, blower wheel and blower motor

if necessary.
7 - Inspect the condensate drain and trap for leaks and

cracks. The drain and trap must also be cleaned

and the trap must be primed with water. Inspect the

rubber hoses connected to the pressure switches for

cracks or loose connections, replace as necessary.

Remove the rubber hoses from the cold end header

box and inspect for any blockage, clean as needed.

If strainers are installed in the hoses remember to

remove and clean before reinstalling the hoses.
8 - Evaluate the heat exchanger integrity by inspecting

the heat exchanger per the AHRI heat exchanger

inspection procedure. This procedure can be

viewed at www.ahrinet.org.

9 - Ensure sufcient combustion air is available to the

furnace. Fresh air grilles and louvers (on the unit
and in the room where the furnace is installed)
must be properly sized, open and unobstructed to
provide combustion air.

10 - Inspect the furnace intake and exhaust pipes to

make sure they are in place, structurally sound,
without holes, blockage or leakage and the
exhaust pipe is sloped toward the furnace. Inspect
terminations to ensure they are free of obstructions
and are structurally sound. Inspect the furnace
return air duct connection to ensure the duct is
sealed to the furnace. Check for air leaks on supply
and return ducts and seal where necessary.

11 - Inspect the furnace return air duct connection to

ensure the duct is sealed to the furnace. Check for
air leaks on supply and return ducts and seal where
necessary.

12 - Check the condition of the furnace cabinet insulation

and repair if necessary.

13 - Perform a complete combustion analysis during the

furnace inspection to ensure proper combustion
and operation. Consult Service Literature for proper
combustion values.

14 - Verify operation of CO detectors and replace

batteries as required.

Perform a general system test. Turn on the furnace to
check operating functions such as the start-up and shut­off operation.

1 - Check the operation of the ignition system, inspect

and clean ame sensor. Check microamps before

and after. Check controls and safety devices (gas

valve, ame sensor, temperature limits). Consult

Service Manual for proper operating range. Thermal

Limits should be checked by restricting airow and

not disconnecting the indoor blower. For additional
details, please see Service and Application Note
H049.

2 - Verify that system total static pressure and airow

settings are within specic operating parameters.

3 - Clock gas meter to ensure that the unit is operating

at the specied ring rate for each stage of

operation. Check the supply pressure and the

manifold pressure on both low re and high re. If

manifold pressure adjustment is necessary, consult

the Service Literature for unit specic information

on adjusting gas pressure. Not all gas valves are
adjustable. Verify correct temperature rise.

Page 63

Winterizing and Condensate Trap Care

1 - Turn off power to the furnace.
2 - Have a shallow pan ready to empty condensate

water.
3 - Remove the clean out cap from the condensate trap

and empty water. Inspect the trap then reinstall the

clean out cap.

Cleaning The Burner Assembly

If cleaning the burner assembly becomes necessary, fol­low the steps below:

1 - Turn off electrical and gas power supplies to furnace.

Remove upper and lower furnace access panels.
2 - Disconnect the wires from the gas valve.
3 - Remove the burner box cover (if equipped).
4 - Disconnect the gas supply line from the gas valve.

Remove gas valve/manifold assembly.

5 - Mark and disconnect sensor wire from the sensor.

Disconnect wires from ame rollout switches.

6 - Disconnect combustion air intake pipe. It may be

necessary to cut the existing pipe to remove burner
box assembly.

7 - Remove four screws which secure burner box

assembly to vest panel. Remove burner box from
the unit.

8 - Use the soft brush attachment on a vacuum cleaner

to gently clean the face of the burners. Visually
inspect the inside of the burners and crossovers for
any blockage caused by foreign matter. Remove
any blockage.

9 - Reinstall the burner box assembly using the existing

four screws. Make sure that the burners line up in
the center of the burner ports.

10 - Reconnect the sensor wire and reconnect the 2-pin

plug to the ignitor wiring harness. Reconnect wires

to ame rollout switches.

11 - Reinstall the gas valve manifold assembly.

Reconnect the gas supply line to the gas valve.

Reinstall the burner box cover.
12 - Reconnect wires to gas valve.
13 - Replace the blower compartment access panel.
14 - Refer to instruction on verifying gas and electrical

connections when re-establishing supplies.
15 - Follow lighting instructions to light and operate

furnace for 5 minutes to ensure that heat exchanger

is clean and dry and that furnace is operating

properly.
16 - Replace heating compartment access panel.

Page 64

Program Unit Capacity/Size Mode

Power-Up - Number displayed represents by integrated control unit size code (furnace model
and capacity). If three horizontal bars are displayed followed by continuous E203, furnace
control does not recognize unit size code. Configure per the following:

Yes

To enter Program Unit
Capacity/Size: push
and hold button next to
7-segment LED display
until solid “P” symbol
appears. Release
button.

IMPORTANT: Field replacement controls may
need to be manually configured to validate
furnace unit size code.

Solid P starts
blinking on
7-Segment LED

P

_

Furnace control in IDLE mode

No heating, cooling or indoor fan

operation)

UNIT SIZE

CODE

0

1

2

3

4

5

6

7

FURNACE MODEL

EL296UH045V36B

EL296UH070V36B

EL296UH090V36C

EL296UH09048C

EL296UH090V60C

EL296UH110V48C

EL296UH110V60C

EL296UH135V60D

−

−

−

No

Turn room thermostat to OFF

UNIT SIZE

CODE

FURNACE MODEL

8

EL296DF0450V36A

9

EL296DF070V48B

11

EL296DF090V60C

U

EL296DF110V60C

Push and hold button. Integrated control will
display unit size code number for each
furnace model for three seconds.

When the correct unit size code is displayed, release
button. Selected code will flash for 10-second period.
During that period, press and hold push button for 5
seconds. Integrated control will store code in
memory and will automatically exit Program Unit
Capacity/Size Mode and reset. (If second period
expires or push button is held less than five seconds,
control will automatically exit Program
Capacity/Size Mode and go into IDLE mode without
storing unit size code. If this happens, programming
function must be repeated).

−

. If

−

−

Verify that the selected unit size code is correct
and stored in non-volatile memory by cycling
the 24 volt power to the furnace control. (At 24
volt power-up of the furnace control, the
7-segment LED will display a unit size code
three horizontal bars display, board does not
recognize unit size code
function must be repeated)

. Programming

FINISHED

Page 65

Requirements for Commonwealth of Massachusetts

Modications to NFPA-54, Chapter 10

Revise NFPA-54 section 10.8.3 to add the following

requirements:

For all side wall, horizontally vented, gas-fueled equip­ment installed in every dwelling, building or structure used
in whole or in part for residential purposes, including those
owned or operated by the Commonwealth and where the
side wall exhaust vent termination is less than seven (7)
feet above the nished grade in the area of the venting, in­cluding but not limited to decks and porches, the following

requirements shall be satised:

1 - INSTALLATION OF CARBON MONOXIDE

DETECTORS. At the time of installation of the side
wall, horizontally vented, gas-fueled equipment,

the installing plumber or gastter shall observe that

a hard-wired carbon monoxide detector with an

alarm and battery backup is installed on the oor

level where the gas equipment is to be installed.

In addition, the installing plumber or gastter shall

observe that a battery-operated or hard-wired
carbon monoxide detector with an alarm is installed
on each additional level of the dwelling, building or
structure served by the side wall, horizontally vented,
gas-fueled equipment. It shall be the responsibility
of the property owner to secure the services of

qualied licensed professionals for the installation

of hard-wired carbon monoxide detectors.

a. I n the event that the side wall, horizontally vented, gas-fueled

equipment is installed in a crawl space or an attic, the hard­wired carbon monoxide detector with alarm and battery

back-up may be installed on the next adjacent oor level.

b. In the event that the requirements of this subdivision cannot

be met at the time of completion of installation, the owner
shall have a period of thirty (30) days to comply with the
above requirements; provided, however, that during said
thirty (30) day period, a battery-operated carbon monoxide
detector with an alarm shall be installed.

2 - APPROVED CARBON MONOXIDE

DETECTORSach carbon monoxide detector as
required in accordance with the above provisions
shall comply with NFPA 720 and be ANSI/UL 2034

listed and IAS certied.

3 - SIGNAGE. A metal or plastic identication plate

shall be permanently mounted to the exterior of the
building at a minimum height of eight (8) feet above
grade directly in line with the exhaust vent terminal
for the horizontally vented, gas-fueled heating
appliance or equipment. The sign shall read, in print
size no less than one-half (1/2) inch in size, “GAS
VENT DIRECTLY BELOW. KEEP CLEAR OF ALL
OBSTRUCTIONS

4 - INSPECTION. The state or local gas inspector

of the side wall, horizontally vented, gas-fueled

equipment shall not approve the installation unless,

upon inspection, the inspector observes carbon

monoxide detectors and signage installed in

accordance with the provisions of 248 CMR 5.08(2)

(a) 1 through 4.

EXEMPTIONS: The following equipment is exempt­from 24 CMR 5.08(2)(a) 1 through 4:

1 - The equipment listed in Chapter 10 entitled

“Equipment Not Required to Be Vented” in the most
current edition of NFPA 54 as adopted by the Board;
and

2 - Product Approved side wall, horizontally vented,

gasfueled equipment installed in a room or structure

separate from the dwelling, building or structure

used in whole or in part for residential purposes.

MANUFACTURER REQUIREMENTS - GAS EQUIP­MENT VENTING SYSTEM PROVIDED.

When the manufacturer of Product Approved side wall,
horizontally vented, gas-fueled equipment provides a
venting system design or venting system components
with the equipment, the instructions provided by the man­ufacturer for installation of the equipment and the venting
system shall include:

1 - Detailed instructions for the installation of the venting

system design or the venting system components:
and

2 - A complete parts list for the venting system design

or venting system.

MANUFACTURER REQUIREMENTS ­GAS EQUIPMENT VENTING SYSTEM NOT PROVIDED.

When the manufacturer of Product Approved side wall,
horizontally vented, gas-fueled equipment does not pro-

vide the parts for venting the ue gases, but identies

“special venting systems,” the following requirements

shall be satised by the manufacturer:

1 - The referenced “special venting system” instructions

shall be included with the appliance or equipment
installation instructions; and

2 - The “special venting systems” shall be Product

Approved by the Board, and the instructions for

that system shall include a parts list and detailed

installation instructions.

A copy of all installation instructions for all Product

Approved side wall, horizontally vented, gas-fueled

equipment, all venting instructions, all parts lists for
venting instructions, and/or all venting design instruc-

tions shall remain with the appliance or equipment at

the completion of the installation.

Page 66

FOR THE PROVINCE OF ONTARIO, HORIZONTAL SIDEWALL VENT APPLICATIONS ONLY

For exterior horizontal venting applications, the 2” X 1.5” reducer for 2” venting at the point where the exhaust pipe exits
the structure is not required in direct or nondirect vent applications in the Province of Ontario. In these applications, the
vent should be oriented such that the exhaust plume is unobjectionable. If the installation requires more separation be-

tween the ue gases and the building structure, a reducer may be installed on the exhaust pipe to increase the ue gas

velocity.

ADDENDUM FOR THE PROVINCE OF SASKATCHEWAN

See below for venting in the province of Saskatchewan. Lennox approves the following termination for use in
Saskatchewan Canada.

C

D

B

12”

A

2” (51MM)

Vent Pipe

A − Clearance above grade or

average snow accumulation

B − Horizontal separation between

intake and exhaust

C − Exhaust pipe length

D − Wall support distance from top

of each pipe (intake/exhaust)

NOTE − Flue gas may be acidic and may adversely affect some building materials. If flue gases impinge
on the building materials, a corrosion−resistant shield should be used to protect the wall surface. The
shield should be constructed using wood, sheet metal or other suitable material. All seams, joints, cracks,
etc. in affected area, should be sealed using an appropriate sealant.

12” (305 mm) Min. 12” (305 mm) Min.

6” (152 mm) Min.
24” (610 mm) Max.

Per: Saskatchewan Code of Practice

6” (152 mm) Max.

3” (76MM)

Vent Pipe

6” (152 mm) Min.
24” (610 mm) Max.

6” (152 mm) Max.

Page 67