Lennox MERIT EL280DF070P36A, MERIT EL280DF090P48B, MERIT EL280DF110P60C Installation Instructions Manual

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Page 1

08/12

*2P0812*

506896−01

*P506896-01*

E 2012 Lennox Industries Inc.

Dallas, Texas, USA

DOWNFLOW

AIR FLOW

INSTALLATION INSTRUCTIONS EL280DF

MERIT® SERIES GAS FURNACE DOWNFLOW AIR DISCHARGE

506896−01 08/2012

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.

THIS MANUAL MUST BE LEFT WITH THE

HOMEOWNER FOR FUTURE REFERENCE

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 installer (or equivalent), service agency or the gas supplier.

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 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

EL280DF Gas Furnace 3. . . . . . . . . . . . . . . . . . . . . . . . . .

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

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

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

General 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Combustion, Dilution & Ventilation Air 5. . . . . . . . . . . . . .

Downflow Installation 8. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Setting Equipment 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Filters 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Duct System 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Venting 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gas Piping 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electrical 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Integrated Control 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Unit Start−Up 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gas Pressure Adjustment 25. . . . . . . . . . . . . . . . . . . . . . . .

Proper Combustion 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

High Altitude 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Other Unit Adjustments 27. . . . . . . . . . . . . . . . . . . . . . . . . .

Heating Sequence of Operation 28. . . . . . . . . . . . . . . . . . .

Service 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Repair Parts List 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Start Up and Performance Checklist 31. . . . . . . . . . . . . . .

Litho U.S.A.

Page 2

Unit Dimensions − inches (mm)

1−1/2 (38)

Front Panel

GAS PIPING INLET

(Either Side)

FLUE OUTLET

(Top)

ELECTRICAL INLET

(Either Side)

RETURN AIR

OPENING

TOP VIEW

3/4

(19)

27−3/4

(705)

19−1/4

(489)

6−5/8 (168) Right 7−1/8 (181) Left

5−3/8 (137) Right 2−3/16 (56) Left

(838)

AIR FLOW

19−7/16

(494)

9/16

(14)

Supply

Air

Supply

Air

9/16

(14)

9/16

(14)

3−1/8

(79)

9/16

(14)

9/16

(14)

19−7/16

(494)

Model No.

A B C D

in. mm in. mm in. mm in. mm

EL280DF070P36A 14−1/2 368 13−3/8 340 13 330 4−3/4 121

EL280DF090P48B 17−1/2 446 16−3/8 416 16 406 6−1/4 159

EL280DF110P60C 21 533 19−7/8 504 19−1/2 495 8 203

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EL280DF Gas Furnace

The EL280DF gas furnace is shipped ready for installation in the downflow position fueled by natural gas. A conversion kit (ordered separately) is required for use in LP/Propane gas applications.

Shipping and Packing List

Package 1 of 1 contains

1 − Assembled EL280DF unit 1 − Bag assembly containing the following:

2 − Screws 1 − Snap bushing 1 − Snap plug 1 − Wire tie 1 − Vent warning label 1 − Owner’s manual and warranty card

The following items may be ordered separately: 1 − Thermostat 1 − LP/Propane changeover kit 1 − Combustible flooring base 1 − High altitude kit

Check equipment for shipping damage. If you find any damage, immediately contact the last carrier.

Safety Information

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 floor and may be difficult to smell. An LP/propane leak detector should be installed in all LP applications.

WARNING

CAUTION

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

Certifications

EL280DF units are CSA International certified. 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). The National Fuel Gas Code is available from the following address:

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

Clearances

Adequate clearance must be made around the air openings into the vestibule area. In order to ensure proper unit operation, combustion and ventilation air supply must be provided according to the current National Fuel Gas Code.

Vent installations must be consistent with the National Fuel Gas Code venting tables (in this instruction) and applicable provisions of local building codes.

This furnace is CSA International certified for installation clearances to combustible material as listed on the unit nameplate and in the tables in figure 13. Accessibility and service clearances must take precedence over fire protection clearances.

Installed Locations

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 floor. 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.

NOTE − Furnace must be adjusted to obtain a temperature rise within the range(s) specified on the unit nameplate. Failure to do so may cause erratic limit operation and may also result in premature heat exchanger failure.

This EL280DF 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 units, it shall be installed in parallel with, or on the upstream side of, cooling units to avoid condensation in the heating compartment. With a parallel flow arrangement, a damper (or other means to control the flow of air) must adequately prevent chilled air from entering the furnace (see figure 1). 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.

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FIGURE 1

AIR HANDLER

GAS UNIT

Dampers

(open during cooling

operation only)

Dampers

(open during heating

operation only)

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

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 EL280DF furnace may be installed in alcoves, closets, attics, basements, garages, and utility rooms in the downflow position.

This furnace design has not been CSA International certified for installation in mobile homes, recreational vehicles, or outdoors.

Use of Furnace as Construction Heater

Lennox does not recommend the use of EL280DF units as a construction heater during any phase of construction. Very low return air temperatures, harmful vapors and operation of the unit with clogged or misplaced filters will damage the unit.

EL280DF units may be used for heating of buildings or structures under construction, if the following conditions are met:

D The vent system must be permanently installed per

these installation instructions.

D A room thermostat must control the furnace. The use of

fixed jumpers that will provide continuous heating is not allowed.

D The return air duct must be provided and sealed to the

furnace.

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

80°F (27°C) must be maintained.

D Air filters must be installed in the system and must be

maintained during construction.

D Air filters must be replaced upon construction comple-

tion.

D The input rate and temperature rise must be set per the

furnace rating plate.

D One hundred percent (100%) outdoor air must be pro-

vided 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 confined space with air from outside.

D The furnace heat exchanger, components, duct system,

air filters and evaporator coils must be thoroughly cleaned following final construction clean−up.

D All furnace operating conditions (including ignition, in-

put rate, temperature rise and venting) must be verified according to these installation instructions.

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 following general recommendations must be considered when installing a EL280DF furnace:

D Place the furnace as close to the center of the air dis-

tribution system as possible. The furnace should also be located close to the chimney or vent termination point.

D Do not install the furnace where drafts might blow direct-

ly into it. This could cause improper combustion and unsafe operation.

D Do not block the furnace combustion air openings with

clothing, boxes, doors, etc. Air is needed for proper combustion and safe unit operation.

D When the furnace is installed in an attic or other insu-

lated space, keep insulation away from the furnace.

NOTE − The Commonwealth of Massachusetts stipulates these additional requirements:

D Gas furnaces shall be installed by a licensed plumb-

er or fitter only.

D The gas cock must be T handle" type. D When a furnace is installed in an attic, the passage-

way to and service area surrounding the equipment shall be floored.

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WARNING

The State of California has determined that this product may contain or produce a chemical or chemicals, in very low doses, which may cause serious illness or death. It may also cause cancer, birth defects or reproductive harm.

Combustion, Dilution & Ventilation Air

In the past, there was no problem in bringing in sufficient outdoor air for combustion. Infiltration 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, appliance vents, chimneys, and fireplaces force additional air that could be used for combustion out of the house. Unless outside air is brought into the house for combustion, 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 EL280DF furnaces to ensure efficient and safe operation. You must consider combustion air needs and requirements for exhaust vents. A portion of this information has been reprinted with permission from the National Fuel Gas Code (ANSI-Z223.1). This reprinted material is not the complete and official position of the ANSI on the referenced subject, which is represented only by the standard in its entirety.

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.

CAUTION

Insufficient 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

All gas-fired appliances require air for the combustion process. If sufficient combustion air is not available, the furnace or other appliances will operate inefficiently 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 fireplaces, exhaust fans, or clothes dryers are used at the same time as the furnace, much more air is necessary to ensure proper combustion and to prevent a downdraft. Insufficient 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 installed in an unconfined or a confined space.

Unconfined Space

An unconfined space is an area such as a basement or large equipment room with a volume greater than 50 cubic feet (1.42 m

) 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 unconfined, it might be necessary to bring in outdoor air for combustion if the structure does not provide enough air by infiltration. 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.

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Confined Space

A confined space is an area with a volume less than 50 cubic feet (1.42 m

) per 1,000 Btu (.29 kW) per hour of the combined input rating of all appliances installed in that space. This definition 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 confined space such as a closet or small equipment room. Even a small leak around the base of the unit at the platform 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 confined space either from inside the building or from outside.

EQUIPMENT IN CONFINED

SPACE ALL AIR FROM INSIDE

CHIMNEY

OR GAS

VENT

FURNACE

WATER

HEATER

OPENINGS (To Adjacent

Room)

NOTE − Each opening shall have a free area of at least one square inch (645 mm

) per 1,000 Btu (.29 kW) per hour of the total input rating of all equipment in the enclosure, but not less than 100 square inches (64516 mm

FIGURE 2

Air from Inside

If the confined space that houses the furnace adjoins a space categorized as unconfined, 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 mm

) per 1,000 Btu (.29 kW) per hour of total input rating of all gas−fired equipment in the confined space. Each opening must be at least 100 square inches (64516 mm

). 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 2.

Air from Outside

If air from outside is brought in for combustion and ventilation, the confined 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 mm

) per 4,000 Btu (1.17

kW) per hour of total input rating of all equipment in the enclosure. See figures 3 and 4. When communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 square inch (645 mm

) per

2,000 Btu (.56 kW) per total input rating of all equipment in the enclosure. See figure 5.

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 fixed in the open position or interlocked with the equipment so that they are opened automatically during equipment operation.

Page 7

EQUIPMENT IN CONFINED SPACE

ALL AIR FROM OUTSIDE

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

NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (645 mm

) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equipment in the enclosure.

VENTILATION LOUVERS

(Each end of attic)

OUTLET

AIR

WATER

HEATER

INLET

AIR

CHIMNEY OR

GAS VENT

FURNACE

VENTILATION

LOUVERS

(For unheated crawl space)

FIGURE 3

EQUIPMENT IN CONFINED SPACE

ALL AIR FROM OUTSIDE

(All Air Through Ventilated Attic)

NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (645 mm

) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equipment in the enclosure.

CHIMNEY

OR GAS

VENT

WATER

HEATER

OUTLET

AIR

VENTILATION LOUVERS

(Each end of attic)

INLET AIR

(Ends 12 in.

above bottom)

FURNACE

FIGURE 4

EQUIPMENT IN

CONFINED SPACE

ALL AIR FROM

OUTSIDE

OUTLET AIR

INLET AIR

WATER

HEATER

CHIMNEY

OR GAS

VENT

NOTE − Each air duct opening shall have a free area of at least one square inch (645 mm

) per 2,000 Btu (.59 kW) per hour of the total input rating of all equipment in the enclosure. If the equipment room is located against an outside wall and the air openings communicate directly with the outdoors, each opening shall have a free area of at least one square inch (645 mm

) per 4,000 Btu (1.17 kW) per hour of the total input rating of all other equipment in the enclosure.

FURNACE

FIGURE 5

Page 8

Downflow Installation

Downflow unit installs in three ways: on non−combustible flooring, on combustible flooring using a downflow combustible flooring base, or on a reverse−flow cooling cabinet. Do not drag the unit across the floor.

Installation on Non−Combustible Flooring (Figure 6)

1 − Cut floor opening keeping in mind clearances listed on

unit rating plate. Also keep in mind gas supply connections, electrical supply, flue and air intake connections and sufficient installation and servicing clearances. See table 1 for correct floor opening size.

2 − Flange warm air plenum and lower the plenum into the

opening.

3 − Set the unit over the plenum and seal the plenum to

the unit.

4 − Ensure that the seal is adequate.

FIGURE 6

EL280DF UNIT

SUPPLY AIR

PLENUM

OPENING

TABLE 1

NON−COMBUSTIBLE FLOOR OPENING SIZE

Cabinet Width

Front to Rear Side to Side

in. mm in. mm

A (14.5") 19−3/4 502 13−1/4 337

B (17.5") 19−3/4 502 16−1/4 413

C (21") 19−3/4 502 19−3/4 502

NOTE − Floor opening dimensions listed are 1/4 inch (6 mm) larger than the unit opening. See unit dimensions on page 2.

Installation on Combustible Flooring (Figure 7)

1 − When unit is installed on a combustible floor, a down-

flow combustible flooring base must be installed between the furnace and the floor. The base must be ordered separately.

See table 2 for opening size to cut in floor.

CAUTION

The furnace and downflow combustible flooring base shall not be installed directly on carpeting, tile, or other combustible material other than wood flooring.

EL280DF UNIT

SUPPLY AIR PLENUM

DOWNFLOW

COMBUSTIBLE

FLOORING BASE

PROPERLY

SIZED FLOOR

OPENING

FIGURE 7

TABLE 2

COMBUSTIBLE FLOOR OPENING SIZE

Cabinet Width

Front to Rear Side to Side

in. mm in. mm

A (14.5")

22 559 15−3/4 400

B (17.5")

22 559 18−3/4 476

C (21")

22 559 22−3/4 578

2 − After opening is cut, set combustible flooring base into

opening.

3 − Check sealing strips on combustible flooring base to

make sure they are properly glued and positioned.

4 − Lower supply air plenum into downflow combustible

flooring base until plenum flanges seal against the strips.

NOTE − Be careful not to damage sealing strips. Check for a tight seal.

5 − Set the furnace over the plenum.

6 − Ensure that the seal between the furnace and plenum

is adequate.

Installation on Cooling Cabinet (Figure 8)

1 − Refer to reverse−flow coil installation instructions for

correctly sized opening in floor and installation of cabinet.

NOTE − Downflow combustible flooring kit is not used

2 − When cooling cabinet is in place, set and secure the

furnace according to the instructions that are provided with the cooling coil. Secure the furnace to the cabinet.

3 − Seal the cabinet and check for air leaks.

Page 9

EL280DF UNIT

COOLING COIL

PLENUM

FIGURE 8

PROPERLY

SIZED FLOOR

OPENING

Return Air Opening −− Downflow Units

The following steps should be taken when installing plenum:

1 − Bottom edge of plenum should be flanged with a

hemmed edge (See figure 9).

SECURE FROM

OUTSIDE CABINET

HEMMED EDGE

PLENUM

SEALING STRIP

(Field Provided)

CABINET SIDE PANEL

Side View

FIGURE 9

2 − Sealing strip should be used.

3 − In all cases, plenum should be secured to top flanges

of furnace with sheet metal screws.

SECURE FROM IN-

SIDE CABINET

HEMMED EDGE

FIBERGLASS SEALING STRIP (Field Provided)

CABINET SIDE

PANEL

PLENUM

Side View

FIGURE 10

4 − In closet installations, it may be impossible to install

sheet metal screws from the outside. In this case,

make plenum with a removable front and install

screws from the inside (See figure 10).

5 − Make certain that an adequate seal is made.

Setting Equipment

WARNING

Do not install the furnace on its front, back or in the horizontal position. See figure 12. Do not connect the return air ducts 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.

Install the EL280DF gas furnace as shipped in the downflow position only. Do not install the furnace hori-

zontally.

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, and installation and service clearances [24 inches (610 mm) at unit front]. The unit must be level.

NOTE − Units with 1/2 hp blower motors are equipped with three flexible legs and one rigid leg. See figure 11. The rigid leg is equipped with a shipping bolt and a flat white plastic washer (rather than the rubber mounting grommet used with a flexible mounting leg). The bolt and washer must

be removed before the furnace is placed into operation. After the bolt and washer have been removed, the rig-

id leg will not touch the blower housing.

FIGURE 11

RIGID LEG

remove shipping bolt and washer

UNITS WITH 1/2 HP BLOWER MOTOR

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.

Page 10

FIGURE 12

Front

Back

Horizontal

Downflow Application

Allow for clearances to combustible materials as indicated on the unit nameplate. Minimum clearances for closet or alcove installations are shown in figure 13.

Downflow Application Installation Clearances

Top

Bottom

Left Side

Right Side

Type of Vent

Connector

Type C Type B1

Top 1 in. (25 mm) 1 in. (25 mm)

*Front 2−1/4 in. (57 mm)** 2−1/4 in. (57 mm)

Back 0 0

Sides 0† 0

Vent 6 in. (152 mm) 1 in. (25 mm)

Floor NC†† NC††

*Front clearance in alcove installation must be 24 in. (610 mm). Maintain a minimum of 24 in. (610 mm) for front service access. ** 4−1/2 in. if a single wall vent pipe is used. †Left side requires 3 in. if a single wall vent is used on 14 −1/2 in. cabinets, or 2 in. if a single wall vent is used on 17 − 1/2 in. cabinets. ††The furnace may be installed on a combustible wood floor if an optional additive base is installed between the furnace and the combustible floor.

FIGURE 13

WARNING

Improper installation of the furnace can result in personal injury or death. Combustion and flue products must never be allowed to enter the return air system or the living space. Use screws and joint tape to seal the return air system to the furnace. In platform installations with bottom return air, 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. The return and supply air duct systems must never be connected to or from other heating devices such as a fireplace or stove, etc. Fire, explosion, carbon monoxide poisoning, personal injury and/or property damage could result.

Filters

This unit is not equipped with a filter or rack. A field−provided high−velocity filter is required for the unit to operate properly. Table 3 lists recommended filter sizes. A filter must be in place any time the unit is operating.

TABLE 3

Cabinet Width

Return Air Filter Size (inches)

A (14−1/2") 14 x 25 x 1 (1) B (17−1/2") 16 x 25 x 1 (1)

C (21") 20 x 25 x 1 (1)

Page 11

Duct System

Use industry-approved standards (such as those published by Air Conditioning Contractors of America or American Society of Heating, Refrigerating and Air Conditioning Engineers) to size and install the supply and return air duct system. This will result in a quiet and low-static system that has uniform air distribution.

NOTE − Do not operate the furnace in the heating mode with an external static pressure that exceeds 0.5 inches w.c. Higher external static pressures may cause erratic limit operation.

Ensure that you have made a seal between the supply air plenum and the furnace and between the furnace and the return air plenum.

Return Air Plenum 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 device (i.e., wood fireplace) 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 flue products can be pulled back down the vent pipe and into the room. This reverse flow of the flue gas may result in incomplete combustion and the formation of carbon monoxide gas. This toxic gas might then be distributed throughout the house by the furnace duct system.

Venting

A 4−inch diameter flue transition is factory-installed on all models. Modifying or removing the flue transition will

cause the unit to operate unsafely and will void the unit certification. The vent connector does not require insula-

tion. The EL280DF series units are classified as fan−assisted Category I furnaces when vertically vented according to the latest edition of National Fuel Gas Code (NFPA 54 / ANSI Z223.1). A fan−assisted Category I furnace is an appliance equipped with an integral mechanical means to either draw or force combustion products through the combustion chamber and/or heat exchanger.

NOTE − Use these instructions as a guide. They do not supersede local codes. This furnace must be vented according to all local codes, these installation instructions, and the provided venting tables in these instructions

The venting tables in this manual were extracted from the National Fuel Gas Code (NFPA 54 / ANSI Z223.1) and are provided as a guide for proper vent installation. Proper application, termination, construction and location of vents must conform to local codes having jurisdiction. In the absence of local codes, the NFGC serves as the defining document.

Refer to the tables and the venting information contained in these instructions to properly size and install the venting system.

IMPORTANT

Once the venting system is installed, attach the Disconnected Vent" warning sticker to a visible area of the plenum near the vent pipe. The warning sticker is provided in the bag assembly. Order kit 66W04 for additional stickers.

WARNING

Asphyxiation hazard. The exhaust vent for this furnace must be securely connected to the furnace flue transition at all times.

FLUE TRANSITION

COLLAR

VENT CONNECTION

“DISCONNECTED VENT”

WARNING

STICKER

FIGURE 14

Use self−drilling sheet metal screws or a mechanical fastener to firmly secure the vent pipe to the round collar of the flue transition. If self−drilling screws are used to attach the vent pipe, it is recommended that three be used. Drive one self−drilling screw through the front and one through each side of the vent pipe and collar. See figure 14.

Install the first vent connector elbow at a minimum of six inches (152 mm) from the furnace vent outlet.

Masonry chimneys used to vent Category I central furnaces must be either tile-lined or lined with a listed metal lining system or dedicated gas vent. Unlined masonry chimneys are prohibited. See figures 15 and 16 for common venting.

Page 12

FIGURE 15

Common Venting Using Tile−Lined Interior Masonry Chimney and Combined Vent Connector

MINIMUM LENGTH = AS SHORT AS PRACTICAL. FOR MAXIMUM LENGTH SEE NOTE TO LEFT

INTERIOR TILE−LINED MASONRY CHIMNEY

NOTE − the chimney must be properly sized per provided venting tables or lined with listed metal lining system.

PERMANENTLY SEALED FIREPLACE OPENING

VENT

CONNECTOR

NOTE− Refer to provided venting

tables for installations.

FURNACE

OTHER

APPLIANCE

Venting Using a Masonry Chimney

The following additional requirements apply when a lined masonry chimney is used to vent this furnace.

A chimney with one or more sides exposed to the outside of the structure is considered to be an exterior chimney.

An exterior masonry chimney that is not tile−lined must be lined with B1 vent or a listed insulated flexible metal vent. An exterior tile−lined chimney that is sealed and capped may be lined with a listed uninsulated flexible metal vent.

If the existing chimney will not accommodate a listed metal liner, either the chimney must be rebuilt to accommodate one of these liners or an alternate approved venting method must be found.

Insulation for the flexible vent pipe must be an encapsulated fiberglass sleeve recommended by the flexible vent pipe manufacturer. See figure 16.

FIGURE 16

Common Venting Using Metal−Lined Masonry Chimney

4 in. (102 mm)

minimum

MIN. LENGTH −− AS

SHORT AS PRACTICAL

MAX. LENGTH

−− SEE NOTE BELOW.

SEALED

PERMANENTLY

SEALED FIREPLACE

OPENING

EXTERIOR

CHIMNEY WITH

METAL

LINER

VENT CONNECTOR

NOTE 1 − Refer to the provided venting tables for installations.

OTHER

APPLIANCE

FURNACE

5 ft. (1.5 m)

minimum

DO NOT insulate the space between the liner and the chimney wall with puffed mica or any other loose granular insulating material

IMPORTANT

SINGLE appliance venting of a fan-assisted furnace into a tile-lined masonry chimney (interior or outside wall) is PROHIBITED. The chimney must first be lined with either type B1 vent or an insulated single wall flexible vent lining system which has been sized according to the provided venting tables and the vent pipe manufacturer’s instructions.

A fan−assisted furnace may be commonly vented into an existing lined masonry chimney if the following conditions are met:

S The chimney is currently serving at least one drafthood

equipped appliance

S The vent connectors and chimney are sized according

to the provided venting tables.

If type B1 double-wall vent is used inside a chimney, no other appliance can be vented into the chimney. The outer wall of type B1 vent pipe must not be exposed to flue products.

A type B1 vent or masonry chimney liner shall terminate above the roof surface with a listed cap or a listed roof assembly according to the terms of their respective listings and the vent manufacturer’s instructions.

When inspection reveals that an existing chimney is not safe for the intended purpose, it shall be rebuilt to conform to nationally recognized standards, lined or relined with suitable materials, or replaced with a gas vent or chimney suitable for venting EL280DF series units. The chimney passageway must be checked periodically to ensure that it is clear and free of obstructions.

Do not install a manual damper, barometric draft regulator, or flue restrictor between the furnace and the chimney.

Page 13

Never connect a Category I appliance to a chimney that is servicing a solid−fuel appliance. If a fireplace chimney flue is used to vent this appliance, the fireplace opening must be permanently sealed.

A type B or listed chimney lining system that passes through an unused masonry chimney flue is not considered to be exposed to the outdoors.

General Venting Requirements

Vent all EL280DF furnaces according to these instructions:

1 − Vent diameter recommendations and maximum allow-

able piping runs are found in the provided venting tables.

2 − In no case should the vent or vent connector diameter

be less than the diameter specified in the provided venting tables.

3 − The minimum vent capacity determined by the sizing

tables must be less than the low fire input rating and the maximum vent capacity must be greater than the high fire input rating.

4 − Single appliance vents − If the vertical vent or tile-lined

chimney has a larger diameter or flow area than the vent connector, use the vertical vent diameter to determine the minimum vent capacity and the vent

connector diameter to determine the maximum vent capacity. The flow area of the vertical vent, however,

shall not exceed 7 times the flow area of the listed appliance categorized vent area, drafthood outlet area or flue collar area unless designed according to approved engineering methods.

5 − Multiple appliance vents − The flow area of the largest

section of vertical vent or chimney shall not exceed 7 times the smallest listed appliance categorized vent area, drafthood outlet area or flue collar area unless designed according to approved engineering methods.

6 − The entire length of single wall metal vent connector

shall be readily accessible for inspection, cleaning, and replacement.

7 − Single appliance venting configurations with zero lat-

eral lengths (tables 5 and NO TAG) are assumed to have no elbows in the vent system. For all other vent configurations, the vent system is assumed to have two 90° elbows. For each additional 90° elbow or equivalent (for example two 45° elbows equal one 90° elbow) beyond two, the maximum capacity listed in the venting table should be reduced by 10% (0.90 x maximum listed capacity).

8 − The common venting tables (6, 7, NO TAG, and

NO TAG) were generated using a maximum horizontal vent connector length of 1−1/2 feet (.46 m) for each inch (25 mm) of connector diameter as follows:

TABLE 4

Connector Diameter

inches (mm)

Maximum Horizontal

Connector Length feet (m)

3 (76) 4−1/2 (1.37)

4 (102) 6 (1.83)

5 (127) 7−1/2 (2.29)

6 (152) 9 (2.74)

7 (178) 10−1/2 (3.20)

9 − If the common vertical vent is offset, the maximum

common vent capacity listed in the common venting tables should be reduced by 20%, the equivalent of two 90° elbows (0.80 x maximum common vent capacity). The horizontal length of the offset shall not exceed 1-1/2 feet (.46 m) for each inch (25 mm) of common vent diameter.

10 − The vent pipe should be as short as possible with the

least number of elbows and angles required to complete the job. Route the vent connector to the vent using the shortest possible route.

11 − A vent connector shall be supported without any dips

or sags and shall slope a minimum of 1/4 inch (6.4 mm) per linear foot (305 mm) of connector, back toward the appliance.

12 − Vent connectors shall be firmly attached to the furnace

flue collar by self−drilling screws or other approved means, except vent connectors of listed type B vent material which shall be assembled according to the manufacturer’s instructions. Joints between sections of single wall connector piping shall be fastened by screws or other approved means.

13 − When the vent connector used for Category I ap-

pliances must be located in or pass through a crawlspace or other areas which may be cold, that portion of the vent connector shall be constructed of listed double-wall type B vent material or material having equivalent insulation qualities.

14 − All venting pipe passing through floors, walls, and ceil-

ings must be installed with the listed clearance to combustible materials and be fire stopped according to local codes. In absence of local codes, refer to NFGC (Z223.1).

15 − No portion of the venting system can extend into, or pass

through any circulation air duct or plenum.

16 − Vent connectors serving Category I appliances shall

not be connected to any portion of mechanical draft systems operating under positive pressure such as Category III or IV venting systems.

17 − If vent connectors are combined prior to entering the

common vent, the maximum common vent capacity listed in the common venting tables must be reduced by 10%, the equivalent of one 90° elbow (0.90 x maximum common vent capacity).

18 − The common vent diameter must always be at least as

large as the largest vent connector diameter.

Page 14

19 − In no case, shall the vent connector be sized more than

two consecutive table size diameters over the size of the draft hood outlet or flue collar outlet.

20 − Do not install a manual damper, barometric draft regu-

lator or flue restrictor between the furnace and the chimney.

21 − When connecting this appliance to an existing dedi-

cated or common venting system, you must inspect the venting system’s general condition and look for signs of corrosion. The existing vent pipe size must conform to these instructions and the provided venting tables. If the existing venting system does not meet these requirements, it must be resized.

TABLE 5

Capacity of Type B Double−Wall Vents with Type B Double−Wall Connectors

Serving a Single Category I Appliance

Height

(feet)

Lateral

(feet)

Vent and Connector Diameter − D (inches)

3 Inch 4 Inch 5 Inch 6 Inch

Appliance Input Rating in Thousands of Btu Per Hour

MIN MAX MIN MAX MIN MAX MIN MAX

0 0 78 0 152 0 251 0 375

2 13 51 18 97 27 157 32 232

4 21 49 30 94 39 153 50 227

6 25 46 36 91 47 149 59 223

0 0 84 0 165 0 276 0 415

2 12 57 16 109 25 178 28 263

5 23 53 32 103 42 171 53 255

8 28 49 39 98 51 164 64 247

0 0 88 0 175 0 295 0 447

2 12 61 17 118 23 194 26 289

5 23 57 32 113 41 187 52 280

10 30 51 41 104 54 176 67 267

0 0 94 0 191 0 327 0 502

2 11 69 15 136 20 226 22 339

5 22 65 30 130 39 219 49 330

10 29 59 40 121 51 206 64 315

15 35 53 48 112 61 195 76 301

0 0 97 0 202 0 349 0 540

2 10 75 14 149 18 250 20 377

5 21 71 29 143 38 242 47 367

10 28 64 38 133 50 229 62 351

15 34 58 46 124 59 217 73 337

20 48 52 55 116 69 206 84 322

0 0 100 0 213 0 374 0 587

2 9 81 13 166 14 283 18 432

5 21 77 28 160 36 275 45 421

10 27 70 37 150 48 262 59 405

15 33 64 44 141 57 249 70 389

20 56 58 53 132 66 237 80 374

30 NA NA 73 11 3 88 214 104 346

NOTE − Single appliance venting configurations with zero lateral lengths are assumed to have no elbows in the vent system. For all other vent configurations, the vent system is assumed to have two 90° elbows. For each additional 90° elbow or equivalent (for example two 45° elbows equal one 90° elbow) beyond two, the maximum capacity listed in the venting table should be reduced by 10 percent (0.90 x maximum listed capacity).

Page 15

TABLE 6

Vent Connector Capacity

Type B Double−Wall Vents with Type B Double−Wall Connectors

Serving Two or More Category I Appliances

Vent

Height

(feet)

Connector

Rise

(feet)

Vent and Connector Diameter − D (inches)

3 Inch 4 Inch 5 Inch 6 Inch

Appliance Input Rating in Thousands of Btu Per Hour

MIN MAX MIN MAX MIN MAX MIN MAX

1 22 37 35 66 46 106 58 164

2 23 41 37 75 48 121 60 183

3 24 44 38 81 49 132 62 199

1 22 40 35 72 49 114 64 176

2 23 44 36 80 51 128 66 195

3 24 47 37 87 53 139 67 210

1 22 43 34 78 49 123 65 189

2 23 47 36 86 51 136 67 206

3 24 50 37 92 52 146 69 220

1 21 50 33 89 47 142 64 220

2 22 53 35 96 49 153 66 235

3 24 55 36 102 51 163 68 248

1 21 54 33 99 46 157 62 246

2 22 57 34 105 48 167 64 259

3 23 60 35 110 50 176 66 271

1 20 62 31 113 45 181 60 288

2 21 64 33 118 47 190 62 299

3 22 66 34 123 48 198 64 309

TABLE 7

Common Vent Capacity

Type B Double−Wall Vents with Type B Double−Wall Connectors

Serving Two or More Category I Appliances

Vent

Height

(feet)

Common Vent Diameter − D (inches)

4 Inch 5 Inch 6 Inch 7 Inch

Appliance Input Rating in Thousands of Btu Per Hour

FAN + FAN FAN + NAT FAN + FAN FAN + NAT FAN + FAN FAN + NAT FAN + FAN FAN + NAT

6 92 81 140 11 6 204 161 309 248

8 101 90 155 129 224 178 339 275

10 110 97 169 141 243 194 367 299

15 125 112 195 164 283 228 427 352

20 136 123 215 183 314 255 475 394

30 152 138 244 210 361 297 547 459

Page 16

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.

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:

1 − Seal any unused openings in the common venting sys-

tem.

2 − Inspect the venting system for proper size and horizontal

pitch. Determine that there is no blockage, restriction, leakage, corrosion, or other deficiencies which could cause an unsafe condition.

3 − Close all building doors and windows and all doors be-

tween the space in which the appliances remaining connected to the common venting system 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 fireplace 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 flue gases at the draft hood relief opening. Use the flame of a match or candle, or smoke from a cigarette, cigar, or pipe.

6 − After determining that each appliance connected to the

common venting system is venting properly, (step 3) return all doors, widows, exhaust fans, fireplace dampers, and any other gas−burning appliances to their previous mode of operation.

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

ing tests, the common venting system must be modified 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 of the National Fuel Gas Code ANSI Z223.1.

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.

CAUTION

If a flexible 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 flexible connector can then be added between the black iron pipe and the gas supply line.

Gas Supply

1 − This unit is shipped standard for left or right side instal-

lation of gas piping. Connect the gas supply to the piping assembly.

2 − When connecting the gas supply piping, consider fac-

tors such as length of run, number of fittings, and furnace rating to avoid excessive pressure drop. Table 8 lists recommended pipe sizes for typical applications.

3 − The gas piping must not run in or through air ducts,

clothes chutes, gas vents or chimneys, dumb waiters, or elevator shafts.

4 − The piping should be sloped 1/4 inch (6.4 mm) per 15

feet (4.57 m) upward toward the meter from the furnace. The piping must be supported at proper intervals [every 8 to 10 feet (2.44 to 3.01 m)] with suitable hangers or straps. Install a drip leg inside vertical pipe runs to the unit.

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 NO TAG.

6 − In some localities, codes may require the installation of

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

IMPORTANT

Compounds used on threaded joints of gas piping must be resistant to the actions of liquified petroleum gases.

NOTE − If emergency shutoff is necessary, shut off the main manual gas valve and disconnect main power to the furnace. The installer should properly label these devices.

Page 17

TABLE 8

Gas Pipe Capacity − ft

/hr (m3/hr)

Nominal

Iron Pipe

Size

inches

(mm)

Internal

Diameter

inches

(mm)

Length of Pipe − feet (m)

(3.048)20(6.096)30(9.144)40(12.192)50(15.240)60(18.288)70(21.336)80(24.384)90(27.432)

100

(30.480)

1/2

(12.7)

.622

(17.799)

172

(4.87)

118

(3.34)

(2.69)

(2.29)

(2.03)

(1.84)

(1.69)

(1.58)

(1.47)

(1.42)

3/4

(19.05)

.824

(20.930)

360

(10.19)

247

(7.00)

199

(5.63)

170

(4.81)

151

(4.28)

137

(3.87)

126

(3.56)

117

(3.31)

110

(3.11)

104

(2.94)

(25.4)

1.049

(26.645)

678

(19.19)

466

(13.19)

374

(10.59)

320

(9.06)

284

(8.04)

257

(7.27)

237

(6.71)

220

(6.23)

207

(5.86)

195

(5.52)

1−1/4

(31.75)

1.380

(35.052)

1350

(38.22)

957

(27.09)

768

(22.25)

657

(18.60)

583

(16.50)

528

(14.95)

486

(13.76)

452

(12.79)

424

(12.00)

400

(11.33)

1−1/2

(38.1)

1.610

(40.894)

2090

(59.18)

1430

(40.49)

1150

(32.56)

985

(27.89)

873

(24.72)

791

(22.39)

728

(20.61)

677

(19.17)

635

(17.98)

600

(17.00)

(50.8)

2.067

(52.502)

4020

(113.83)

2760

(78.15)

2220

(62.86)

1900

(53.80)

1680

(47.57)

1520

(43.04)

1400

(39.64)

1300

(36.81)

1220

(34.55)

1160

(32.844)

2−1/2

(63.5)

2.469

(67.713)

6400

(181.22)

4400

(124.59)

3530

(99.95)

3020

(85.51)

2680

(75.88)

2480

(70.22)

2230

(63.14)

2080

(58.89)

1950

(55.22)

1840

(52.10)

(76.2)

3.068

(77.927)

11300

(319.98)

7780

(220.30)

6250

(176.98)

5350

(151.49)

4740

(134.22)

4290

(121.47)

3950

(111.85)

3670

(103.92)

3450

(97.69)

3260

(92.31)

NOTE − Capacity given in cubic feet (m3 ) of gas per hour and based on 0.60 specific gravity gas.

GROUND

JOINT

UNION

AUTOMATIC

GAS VALVE

(with manual

shut−off valve)

FIELD

PROVIDED

AND INSTALLED

GROUND

JOINT

UNION

Left Side Piping

(Standard)

Right Side Piping

(Alternate)

AUTOMATIC

GAS VALVE

(with manual

shut−off valve)

DRIP LEG

MANUAL

MAIN SHUT−OFF

VALV E

MANUAL

MAIN SHUT−OFF

VALV E

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

FIGURE 17

Page 18

Leak Check

After gas piping is completed, carefully check all piping connections (factory− and field−installed) for gas leaks. Use a leak detecting solution or other preferred means.

NOTE − If emergency shutoff is necessary, shut off the main manual gas valve and disconnect the main power to the furnace. The installer should properly label these devices.

CAUTION

Some soaps used for leak detection are corrosive to certain metals. Carefully rinse piping thoroughly after leak test has been completed. Do not use matches, candles, flame or other sources of ignition to check for gas leaks.

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.).

IMPORTANT

When testing pressure of gas lines, gas valve must be disconnected and isolated. See figure 18. Gas valves can be damaged if subjected to pressures greater than 1/2 psig (3.48 kPa, 14 inches w.c.).

MANUAL MAIN

SHUT−OFF VALVE

WILL NOT HOLD

NORMAL TEST

PRESSURE

CAP

ISOLATE

GAS VALVE

FURNACE

FIGURE 18

1/8 NPT PLUG

Electrical

ELECTROSTATIC DISCHARGE (ESD)

Precautions and Procedures

CAUTION

Electrostatic discharge can affect electronic components. Take precautions to neutralize electrostatic charge by touching your hand and tools to metal prior to handling the control.

The unit is equipped with a field 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 hand side, clip the wire ties that bundle the wires together. Secure the excess wire to the existing harness to protect it from damage.

INTERIOR MAKE−UP BOX INSTALLATION

(Right Side)

FIGURE 19

MAKE−UP

BOX

Cut the two wire ties to extend power wires for right side only

Refer to figure 20 for schematic wiring diagram and troubleshooting and table 9 for field wiring.

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.

NOTE − Unit nameplate states maximum current draw. Maximum over−current protection allowed is 15 AMP.

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, check to make sure the wires will be long enough for servicing at a later date. Make sure that thermostat wire is long enough to facilitate future removal of blower for service.

Complete the wiring connections to the equipment. 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 field make−up box.

NOTE − The EL280DF furnace contains electronic components that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.

Accessory Terminals

One line voltage EAC" 1/4" spade terminal is provided on the furnace integrated control. See figure 21 for integrated control configuration. This terminal is energized when the indoor blower is operating. Any accessory rated up to one amp can be connected to this terminal with the neutral leg

Page 19

of the circuit being connected to one of the provided neutral terminals. If an accessory rated at greater than one amp is connected to this terminal, it is necessary to use an external relay.

One line voltage HUM" 1/4" spade terminnal is provided on the furnace integrated control. See figure 21 for integrated control configuration. This terminal is energized in the heating mode when the combustion air inducer is operating. Any humidifier rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to one of the provided neutral terminals. If a humidifier rated at greater than one amp is connected to this terminal, it is necessary to use an external relay relay.

One 24V "H" 1/4" spade terminal is provided on the furnace integrated control. See figure 21 for integrated control configuration. The terminal is energized in the heating mode when the combustion air inducer is operating and the pressure switch is closed. Any humidifier rated up to 0.5 amp can be connected to this terminal with the ground leg of the circuit connected to ground or the "C" terminal.

Generator Use − Voltage Requirements

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

S The furnace requires 120 volts +

10% (Range: 108

volts to 132 volts).

S The furnace operates at 60 Hz +

5% (Range: 57 Hz to

63 Hz).

S The furnace integrated control requires both proper

polarity and proper ground. Both polarity and proper grounding should be checked before attempting to operate the furnace on either permanent or temporary power.

S Generator should have a wave form distortion of less

than 5% total harmonic distortion (THC).

Thermostat

Install the room thermostat according to the instructions provided with the thermostat. See table 9 for thermostat designations. If the furnace is being matched with a heat pump, refer to the FM21 installation instruction or appropriate dual fuel thermostat instructions.

Indoor Blower Speeds

1 − When the thermostat is set to FAN ON," the indoor

blower will run continuously on the low heat speed when there is no cooling or heating demand.

2 − When the EL280DF is operating in the high−fire or low−

fire heating mode, the indoor blower will run on the corresponding heating speed.

3 − When the EL280DF is operating in the low cool or the

high cool cooling mode, the indoor blower will run on the corresponding cooling speed.

Page 20

TABLE 9

Field Wiring Applications

Thermostat

DIP Switch Settings and On−Board Links (See figure 21)

Wiring Connections

DIP Switch 1

W915

Two−Stage

Cooling

W951

Heat Pumps

1 Heat / 1 Cool

NOTE − Use DIP switch 2 to set second−stage heat ON delay. OFF10 minutes. ON−15 minutes.

ON Intact Intact

T’STAT

CONTROL

TERM. STRIP

OUTDOOR

UNIT

1 Heat / 2 Cool

NOTE − Use DIP switch 2 to set second−stage heat ON delay. OFF−10 minutes. ON−15 minutes.

ON Cut Intact

T’STAT

CONTROL

TERM. STRIP

OUTDOOR

UNIT

Page 21

TABLE 9

Field Wiring Applications (Continued)

Thermostat

DIP Switch Settings and On−Board Links (See figure 21)

Wiring Connections

DIP Switch 1

W915

Two−Stage

Cooling

W951

Heat Pumps

2 Heat / 2 Cool OFF Cut Intact

T’STAT

CONTROL

TERM. STRIP

OUTDOOR

UNIT

2 Heat / 1 Cool OFF Intact Intact

T’STAT

CONTROL

TERM. STRIP

OUTDOOR

UNIT

Page 22

FIGURE 20

EL280DF Schematic Wiring Diagram

Page 23

Integrated Control

FIGURE 21

TWO−STAGE INTEGRATED CONTROL

THERMOSTAT CONNECTIONS (TB1)

1/4" QUICK CONNECT TERMINALS

DIP SWITCH FUNCTIONS

DIP

SWITCHES

DIAGNOSTIC

LEDs

ON−BOARD

LINKS

1= ERROR CODE RECALL H= 24V HUMIDIFIER OUTPUT L= LENNOX SYSTEM OPERATION MONITOR

SENSE = 120 VAC OUTPUT TO FLAME SENSER

NEUTRALS= 120 VAC NEUTRAL

PARK = DEAD TERMINAL FOR UNUSED BLOWER LEAD HEAT LOW = 120 VAC OUTPUT TO CIRC BLWR −− LOW HT SPEED HEAT HIGH/ COOL LOW = 120 VAC OUTPUT TO CIRC BLWR −−

HIGH HEAT AND LOW COOL SPEED

COOL HIGH = 120 VAC OUTPUT TO CIRC BLWR −− HIGH COOL SPEED

DIP SWITCH(ES) FUNCTION

1 −− 2 Stage T’stat Selects t/stat type (single or two−stage)

2 −− 2nd Stage Delay Second stage ON delay (single−stage t’stat)

3 & 4 −− Heat Off Delay Heating fan OFF delay

5 −− Cool Off Delay Cooling fan OFF delay

W915

W951

EL280DF units are equipped with a two−stage integrated control. This control manages ignition timing and fan off delays 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.

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 two− stage thermostat. If a single−stage thermostat is to be used, the DIP switch must be repositioned.

Select OFF" for two−stage heating operation con-

trolled by a two−stage heating thermostat (factory setting);

b − Select ON" for two−stage heating operation con-

trolled 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 deter-

mine 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 10−minute delay before second− stage heat is initiated. If the switch is toggled to the ON position, it will provide a 15−minute delay before second− stage heat is initiated. This switch is only activated when the thermostat selector jumper is positioned for SINGLE− stage thermostat use.

Switches 3 and 4 −− Heating Blower−Off Delay −− The heating blower−on delay of 45 seconds is not adjustable. The heating blower−off delay (time that the blower operates after the heating demand has been satisfied) can be adjusted by moving switches 3 and 4 on the integrated control. The unit is shipped from the factory with a heating blower−off delay of 90 seconds. The heating 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

Page 24

settings provide lower supply air temperatures; shorter settings provide higher supply air temperatures.Table 10 provides the blower off timings that will result from different switch settings.

TABLE 10

Heating Blower−Off Delay Switch Settings

Blower Off Delay

(Seconds)

Switch 3 Switch 4

60 Off On 90

(factory setting)

Off Off

120 On Off 180 On On

Switch 5 −− Cooling Blower−Off Delay −− The cooling blower−off delay (time that the blower operates after the cooling demand has been satisfied) can be adjusted by moving switch 5 on the integrated control. The switch is factory−set in the OFF position, which provides a cooling blower−off delay of 45 seconds. If the switch is toggled to the ON position, it will provide a 2−second cooling blower−off delay

On−Board Link W951

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 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

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 link is not cut the outdoor unit will operate in second−stage cooling only.

Unit Start−Up

FOR YOUR SAFETY READ BEFORE LIGHTING

WARNING

Do not use this furnace if any part has been underwater. A flood−damaged furnace is extremely dangerous. Attempts to use the furnace can result in fire or explosion. Immediately call a qualified 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

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 smell all around the appliance area for

gas. Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor.

The gas valve on the EL280DF unit will be equipped with a gas control switch. Use only your hand to move the switch. Never use tools. If the switch will not turn or if the control switch will not move by hand, do not try to repair it.

Placing the furnace into operation:

EL280DF units are equipped with an automatic ignition system. Do not attempt to manually light burners on these furnaces. 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 units with an automatic ignition system.

WARNING

If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or death.

Gas Valve Operation (Figure 22)

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 upper access panel.

6 − Move switch on gas valve to OFF. Do not force. See

figure 22.

7 − Wait five 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.

Page 25

FIGURE 22

GAS VALVE SHOWN IN ON POSITION

INLET PRESSURE POST

HIGH FIRE ADJUSTMENT

SCREW

(under cap)

MANIFOLD

PRESSURE TAP

8 − Move switch on gas valve to ON. Do not force. See fig-

ure 22.

9 − Replace the upper 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 upper access panel. 4 − Move switch on gas valve to OFF. Do not force. 5 − Replace the upper 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 circuit breaker? 5 − Is the filter dirty or plugged? Dirty or plugged filters 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 lock out? If the unit locks out

again, call the service technician to inspect the unit for

blockages. 10 − Is pressure switch closed? Obstructed flue will cause

unit to shut off at pressure switch. Check flue and outlet

for blockages. 11 − Are flame rollout switches tripped? If flame rollout

switches are tripped, call the service technician for in-

spection.

Gas Pressure Adjustment

Gas Flow (Approximate)

TABLE 11

GAS METER CLOCKING CHART

EL280DF

Unit

Seconds for One Revolution

Natural LP

1 cu ft

Dial

2 cu ft

Dial

1 cu ft

Dial

2 cu ft

DIAL

−045 80 160 200 400

−070 55 11 0 136 272

−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

Furnace should operate at least 5 minutes before checking gas flow. 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 11. If manifold pressure matches table 13 and rate is incorrect, check gas orifices 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 22. 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 13 for supply line pressure.

Manifold Pressure

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

1 − Connect test gauge to manifold pressure tap (figure

22) gas valve.

2 − Ignite unit on high fire and let run for 5 minutes to allow

for steady state conditions.

3 − After allowing unit to stabilize for 5 minutes, record

manifold pressure and compare to value given in table

13.

4 − If necessary, make adjustments. Figure 22 shows

location of high fire adjustment screw.

5 − If an adjustment is made on high fire, re−check man-

ifold pressure on low fire. Do not adjust low fire man- ifold pressure. If low fire manifold pressure is more than 1/2" above or below value specified in table 13, replace valve.

NOTE − Shut unit off and remove manometer as soon as an accurate reading has been obtained. Take care to remove barbed fitting and replace threaded plug.

Page 26

Proper Combustion

Furnace should operate minimum 15 minutes with correct manifold pressure and gas flow rate before checking combustion. Table 12 shows acceptable combustion for ALL EL280DF models. The maximum carbon monoxide

reading should not exceed 50 ppm

TABLE 12

Firing Rate

CO2%

For Nat

CO2%

For L.P.

High Fire 6.8 − 7.4 7.5 − 9.0

Low Fire 4.2 − 5.7 5.0 − 6.0

High Altitude

The manifold pressure may require adjustment and combustion air pressure switch may need replacing to ensure proper combustion at higher altitudes. Refer to table 13 for manifold pressure and table 14 for pressure switch change and gas conversion kits.

IMPORTANT

For safety, shut unit off and remove manometer as soon as an accurate reading has been obtained. Take care to replace pressure tap plug.

TABLE 13

Manifold Pressure Settings at all Altitudes

Unit

Input

Gas

Manifold

Pressure in.wg.

0−4500 ft.

Manifold

Pressure in.wg.

4501−7500 ft.

Manifold

Pressure in.wg.

7501 − 10,000 ft.

Supply Line

Pressure

in. w.g.

Low Fire High Fire Low Fire High Fire Low Fire High Fire Min Max

070

Natural 1.7 3.5 1.5 3.2 1.7 3.5 4.5 13.0

LP/propane

4.9 10.0 4.9 10.0 4.9 10.0 11.0 13.0

090

Natural 1.7 3.5 1.5 3.0 1.7 3.5 4.5 13.0

LP/propane

4.9 10.0 4.9 10.0 4.9 10.0 11.0 13.0

110

Natural 1.7 3.5 1.5 3.2 1.7 3.5 4.5 13.0

LP/propane

4.9 10.0 4.9 10.0 4.9 10.0 11.0 13.0

This is the only permissible derate for these units.

Natural gas high altitude orifice kit required.

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. NOTE − Units may be installed at altitudes up to 4500 ft. above sea level without modifications.

TABLE 14

Pressure Switch and Gas Conversion Kits at all Altitudes

Unit

Input

High Altitude Pressure Switch Kit

High Altitude

Natural Gas Kit

LP/Propane Gas Kit

LP/Propane to

Natural Kit

0 − 4500 ft. 4501 − 7500 ft. 7501 − 10,000 ft. 7501 − 10,000 ft. 0 − 7500 ft 7501 − 10,000 ft. 0 − 7500 ft.Min

070

No Change No Change

73W36

73W37 77W07 77W11 77W09

090 73W36

110 73W35

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.

Page 27

Other Unit Adjustments

Primary and Secondary Limits

The primary limit is located on the heating compartment vestibule panel. The secondary limits (if equipped) are located in the blower compartment, attached to the back side of the blower. These auto reset limits are factory−set and require no adjustment.

Flame Rollout Switches

These manually reset switches are located on the burner box.

Pressure Switch

The pressure switch is located in the heating compartment adjacent to the combustion air inducer. The switch checks for proper combustion air inducer operation before allowing ignition trial. The switch is factory−set and requires no adjustment.

Temperature Rise

After the furnace has been started, and supply and return air temperatures have been allowed to stabilize, check the temperature rise. If necessary, adjust the blower speed to maintain the temperature rise within the range shown on the unit nameplate. Increase the blower speed to decrease the temperature. Decrease the blower speed to increase the temperature rise. Failure to adjust the temperature rise may cause erratic limit operation.

Fan Control

The fan−on time of 30 seconds is not adjustable. The heat fan−off delay (amount of time that the blower operates after the heat demand has been satisfied) may be adjusted by changing DIP switches 3 and 4. See figure 23 and table 10. The unit is shipped with a factory fan−off delay setting of 90 seconds. The fan−off delay affects comfort and is adjustable to satisfy individual applications. Adjust the fan−off delay to achieve a supply air temperature between 90° and 110°F at the moment that the blower is de−energized. Longer off delay settings provide lower return air temperatures; shorter settings provide higher return air temperatures. See figure 23.

HEAT FAN-OFF TIME IN SECONDS

FIGURE 23

60sec.

90sec.

120sec.

180sec.

12345 12345

To adjust fan−off timing, flip dip switch to desired setting.

Input Voltage Requirements

The circuit is designed to be operated with AC voltage. A voltage of 12 to 33VAC is required to energize the motor. Expected current draw will be less than 20mA.

Blower Speeds

Follow the steps below to change the blower speeds. 1 − Turn off electrical power to furnace. 2 − Remove blower access panel. 3 − Disconnect existing speed tap at integrated control

speed terminal.

NOTE − Termination of any unused motor leads must be insulated.

4 − Place unused blower speed tap on integrated control

PARK" terminal or insulate.

5 − Refer to blower speed selection chart on unit wiring dia-

gram for desired heating or cooling speed. See Blower performance data beginning on the next page.

6 − Connect selected speed tap at integrated control

speed terminal. 7 − Resecure blower access panel. 8 − Turn on electrical power to furnace. 9 − Recheck temperature rise.

Electronic Ignition

The integrated control has an added feature of an internal Watchguard control. The feature serves as an automatic reset device for integrated control lockout caused by ignition failure. This type of lockout is usually due to low gas line pressure. After one hour of continuous thermostat demand for heat, the Watchguard will break and remake thermostat demand to the furnace and automatically reset the integrated control to begin the ignition sequence.

Page 28

Heating Sequence of Operation

When there is a call for heat, the integrated control runs a self check. The control checks for S10 primary limit, S21 secondary limit (s) and S47 rollout switch normally closed contacts. The control also checks for S102 high heat and S128 low heat prove switch normally open contacts. Once self check is complete and all safety switches are operational, heat call can continue.

Two−Stage Thermostat, Two Stage Heat. Dip Switch

set at TWO".

1− SureLight control energizes combustion air inducer B6

on low heat speed. Combustion air inducer runs until S128 low heat prove switch contacts close (switch must close within 2 1/2 minutes or control goes into Watchguard Pressure Switch mode. High heat prove switch S102 may also close). A 15 second pre−purge follows once S128 closes.

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

NOTE − If the furnace is operating on continuous fan mode (terminal R" and G" are energized), the combustion air inducer will energize on high speed, the gas valve will energize on second−stage heat and the furnace will operate on high fire. Furnace will stay on high fire for 60 seconds then switch to low fire.

2− SureLight control begins 20 second ignitor warm up

period.

3− Gas valve opens on first stage for a 4 second trial for

ignition. Ignitor stays energized during the trial or until flame sensed.

4− Flame is sensed, gas valve remains on first stage heat,

ignitor de−energizes.

5− After 30 second delay, indoor blower B3 is energized

on low heat speed.

The furnace will stay in this mode until first stage demand is satisfied OR a second stage heat demand is initiated.

6− Second stage heat demand initiated. A 30 second sec-

ond stage recognition period begins.

7− The combustion air inducer ramps up to high heat

speed.

8− S102 high heat prove switch closes and the gas valve

energizes second stage heat.

9− B3 indoor blower switches to high heat speed.

Single−Stage Thermostat, Two Stage Heat. Dip

Switch set at SINGLE"

1− SureLight control energizes combustion air inducer B6

2− SureLight control begins 20 second ignitor warm up

period.

3− Gas valve opens on first stage for a 4 second trial for

ignition. Ignitor stays energized during the trial or until flame sensed.

4− Flame is sensed, gas valve remains on first stage heat,

ignitor de−energizes.

5− After 30 second delay, indoor blower B3 is energized

on low heat speed.

6− A 10 minute (factory set) or 15 minute (field set) second

stage heat delay period begins.

7− After the delay the combustion air inducer ramps up to

high heat speed.

8− S102 high heat prove switch closes and the gas valve

energizes second stage heat.

9− B3 indoor blower switches to high heat speed.

Page 29

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.

At the beginning of each heating season, a licensed professional technician (or equivalent) should check the system as follows:

Blower

Check the blower wheel for debris and clean if necessary. The blower motors are prelubricated for extended bearing life. No further lubrication is needed.

WARNING

Filters

All EL280DF filters are installed external to the unit. Filters should be inspected monthly. Clean or replace the filters when necessary to ensure that the furnace operates properly. Replacement filters must be rated for high velocity airflow. Table 3 lists recommended filter sizes.

Flue And Chimney

1 − Check flue pipe, chimney and all connections for tight-

ness and to make sure there is no blockage.

2 − Check unit for proper draft.

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 ac-

cess panel in place. Unit Nameplate__________Actual__________

Cleaning the Burners

NOTE − Use papers or protective covering in front of the furnace during cleaning.

1 − Turn off both electrical and gas power supplies to fur-

nace.

3 − Label the wires from gas valve, rollout switches, prima-

ry limit switch and make−up box then disconnect them.

4 − Disconnect gas supply piping. Remove the four screws

securing the burner manifold assembly to the vestibule panel and remove the assembly from the unit.

5 − Remove 4 screws securing burner box and remove

burner box.

6− To clean burners, run a vacuum cleaner with a soft brush

attachment over the face of burners. Visually inspect inside the burners and crossovers for any blockage caused by foreign matter. Remove any blockage. Figure 24 shows burner detail.

7− Reinstall burner box, manifold assembly and burner box

cover.

8− Reconnect all wires.

9− Reconnect gas supply piping.

10− Turn on power and gas supply to unit.

11− Set thermostat and check for proper operation.

12− Check all piping connections, factory and field, for gas

leaks. Use a leak detecting solution or other preferred means.

CAUTION

13− If a leak is detected, shut gas and electricity off and

repair leak.

14− Repeat steps 12 and 13 until no leaks are detected.

15− Replace access panel.

Page 30

EL280DF BURNER, COMBUSTION AIR INDUCER ASSEMBLY &

HEAT EXCHANGER REMOVAL

FIGURE 24

burners

burner box assembly

manifold and gas valve

retention rings

cross over

Repair Parts List

The following repair parts are available through independent Lennox dealers. When ordering parts, include the complete furnace model number listed on the CSA International nameplate −− Example: EL280DF110P60C.

All service must be performed by a licensed professional installer (or equivalent), service agency, or gas supplier.

Cabinet Parts

Main access panel Blower access panel Top cap

Control Panel Parts

Transformer Integrated control Door interlock switch Circuit breaker

Blower Parts

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

Heating Parts

Flame Sensor

Heat exchanger assembly Gas manifold Combustion air inducer Gas valve Main burner cluster Main burner orifices Pressure switches Ignitor Primary limit control Flame rollout switch

Secondary limit

Page 31

Start−Up & Performance Check List

Unit Model Number_______________

Serial Number___________________

UNIT SET UP

(typical)

Gas Supply Pressure

SUPPLY

AIR

Line Voltage

Filter

RETURN

AIR

RETURN

AIR

GAS SUPPLY

Natural Gas

LP/Propane Gas

Piping Connections Tight

Leak Tested

Supply Line Pressure  W.C.________

VENT / EXHAUST PIPE

Secure to Unit

Elbows Secured to Pipe

Vent Pipe Supported

Roof Flashing (water tight)

DUCT SYSTEM

SUPPLY AIR DUCT

Sealed

Insulated (if necessary)

Registers Open and Unobstructed

RETURN DUCT

Sealed

Filter Installed and Clean

Grilles Unobstructed

INTEGRATED CONTROL

DIP Switches Set (if applicable)

Appropriate Links in Place (if applicable)

VOLTAGE CHECK

Supply Voltage _____

Electrical Connections Tight

upflow furnace shown

Page 32

Contractor’s: Name_________________________Telephone_____________Checklist Completed____________________

Job Address_____−________________________________Technician’s Name___________________________________

UNIT OPERATION

(typical)

HEATING MODE

GAS MANIFOLD PRESSURE W.C._____

COMBUSTION SAMPLE CO

2%______

CO PPM_______

INDOOR BLOWER AMPS______

TEMPERATURE RISE

Supply Duct Temperature ________ Return Duct Temperature _ _____

Temperature Rise = ________

COOLING MODE

INDOOR BLOWER AMPS______

TEMPERATURE DROP

Return Duct Temperature _________ Supply Duct Temperature

_ _______

DRAIN LINE

Leak Free

THERMOSTAT

Adjusted and Programmed

Operation Explained to Owner

RETURN

AIR

RETURN

AIR

SUPPLY

AIR

Blower Motor Amps

Thermostat

Combustion CO

Duct Static

Gas Manifold Pressure

Temperatures

Filter

Temperature Drop = _________

TOTAL EXTERNAL STATIC (dry coil)

Supply External Static _______

Return External Static + ______

Total External Static = _______

TOTAL EXTERNAL STATIC (dry coil)

Supply External Static _______

Return External Static + ______ Total External Static = _______

upflow furnace shown

Lennox MERIT EL280DF070P36A, MERIT EL280DF090P48B, MERIT EL280DF110P60C Installation Instructions Manual

Specifications and Main Features

Frequently Asked Questions

User Manual