E 2000 Lennox Industries Inc.

Dallas, Texas, USA



INSTALLATION

INSTRUCTIONS

G26 SERIES UNITS

GAS UNITS

504,228M

11/2000

Supersedes 503,885M

Litho U.S.A.

Table of Contents

Unit Dimensions

Requirements

General

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

G26 Parts Identification . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Installation - Setting Equipment

Return Air Opening Guidelines

Filters & Optional Filter Assembly

. . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . .

Duct System

Pipe & Fittings Specifications

. . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Vent Piping Guidelines

. . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . .

Joint Cementing Procedure

Venting Practices

Gas Piping

Electrical

Unit Start-Up

. . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gas Pressure Adjustment

High Altitude Information

Other Unit Adjustments

Service

. . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Repair Parts

. . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Start-Up & Performance Check List . . . . . . . . . . . . . .

6

7

5

5

4

4

2

3

8

9

7

8

15

16

23

26

26

31

20

21

22

22

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

WARNING

If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or death.

Do not store or use gasoline or other flammable vapors and liquids in the viĆ cinity of this or any other appliance.

Installation and service must be performed by a qualified installer, service agency or the gas supplier.

WHAT TO DO IF YOU SMELL GAS:

D Do not try to light any appliance.

D Extinguish any open flames.

D Do not touch any electrical switch; do not use any phone in your building.

D Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.

D If you cannot reach your gas supplier, call the fire department.

11/00

*2P1100* Page 1

504,228M

*P504228M*

G26 Unit Dimensions - inches (mm)

1 1/16

(41)

5/8

(16)

1 1/16

(41)

3 5/8

(92)

18 7/8

(479)

B

SUPPLY

AIR

OPENING

23 3/4 (603)

25 (635)

TOP VIEW

28 1/2

(724)

F

2

(51)

COMBUSTION

AIR INTAKE

2 1/2 (64)

EXHAUST

AIR OUTLET

21 3/4

(552)

4 1/2

(114)

23

(584) CONDENSATE

DRAIN

(Both Sides)

ELECTRICAL

INLETS

(Both Sides)

C

23 (584)

RETURN AIR

KNOCKOUT

(Either Side)

1Ć15/16 (49)

23 (584)

Return Air

Knockout (Bottom)

SIDE VIEW

GAS PIPING

INLET

(Both Sides)

4 (102)

4 (102)

46

(1168)

EXTERNAL

SIDE RETURN

AIR FILTER KIT

(Either Side)

(Optional)

G H

A

AIR FLOW

5/8 (16)

E D

Return Air

Knockout (Bottom)

FRONT VIEW

G26Q2-50

G26Q3Ć50

G26Q3Ć75

G26Q3/4Ć100

G26Q4/5-75

G26Q4/5Ć100

G26Q3/4-125

G26Q4/5Ć125 in.

A mm in.

B C D E mm in.

mm in.

mm in.

mm in.

F mm

16Ć1/4 413 14Ć1/8 359 12 305 12 305 2Ć1/8 54 7Ć5/8 194 in.

G mm

14 in.

H mm

356 12Ć3/4 324

21Ć1/4 540 19Ć1/8 486 18 457 18 457 1Ć5/8 41 10Ć1/8 257 20 508 18Ć3/4 476

26Ć1/4 667 24Ć1/8 613 18 457 18 457 4Ć1/8 105 12Ć5/8 321 20 508 18Ć3/4 476

Page 2

G26 Parts Arrangement

GLASS FIBER GASKET

FRESH AIR

INTAKE FITTING

BURNER BOX

ASSEMBLY

PATCH

PLATE

G26 PARTS IDENTIFICATION

FLUE COLLAR

WARM

HEADER

(COLLECTOR)

BOX

PATCH PLATE WITH

BARBED FITTING

AND FLAME

ROLL-OUT SWITCH

DuralokPlus TM

HEAT EXCHANGER

ASSEMBLY

TOP CAP

FLUE

TRANSITION

CABINET

FLAME SIGHT

GLASS

BURNER

BOX

COVER GAS VALVE AND

MANIFOLD

COMBUSTION AIR

PROVE

(PRESSURE)

SWITCH

SUPPLY

AIR

BLOWER

BURNER

ACCESS

PANEL

BLOWER

ACCESS

DOOR

COMBUSTION AIR

INDUCER

COMBUSTION AIR

ORIFICE

COLD HEADER

(COLLECTOR)

BOX

FIGURE 1

Page 3

PRIMARY LIMIT

(ALTERNATE STYLES)

CONDENSER COIL

CONTROL TRANSFORMER

CONTROL VOLTAGE

CIRCUIT BREAKER

DOOR INTERLOCK SWITCH

CONTROL BOX COVER

Requirements

All G26 units are CSA International certified to ANSI

Z21.47 and CSA 2.3 standards.

In the USA, installation of Lennox gas central furnaces must conform with local building codes. In the absence of local codes, units must be installed according to the current NaĆ tional Fuel Gas Code (ANSI-Z223.1) in the United States.

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 CAN/CGA-B149.1 Installation Code for Natural Gas Burning Appliances and Equipment" and

CAN/CGA-B149.2 Installation Code for Propane Gas

Burning Appliances and Equipment," local plumbing or waste water codes and other applicable local codes.

Adequate clearance must be made around the air openĆ ings into the vestibule area. Provisions must be made for proper operation and for combustion air and ventilation air supply according to the current National Fuel Gas Code or

CAN/CGA-B149 standards.

This furnace is CSA International certified for installation clearances to combustible material as listed on the unit rating plate and in table 1.

TABLE 1

Clearances Location Inches (mm)

Service access

Front

Condensate side

24 (610)

3 (76)

(from side of unit) materials

Top

Exhaust

Side, rear, and front

1 (25)

0

0

Floor 0*

*Appliance shall not be installed directly on carpeting, tile or other combustible mateĆ rial other than wood flooring.

NOTE-Service access clearance must be maintained.

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

Accessibility and service clearances must take preceĆ dence over fire protection clearances.

For installation in a residential garage, the furnace must be installed so that the burner(s) and the ignition source are loĆ cated 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 or CAN/CGA B149.1 and B149.2 standards.

The furnace must be adjusted to obtain a temperature rise within the range specified on the unit rating plate.

When installed, the 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

Wiring to be done in the field, between the furnace and deĆ vices not attached to the furnace or between separate deĆ vices which are field-installed and located, shall conform with the temperature limitation for type T wire [63°F (17°C) rise] when installed in accordance with these instructions.

G26 unit must be installed so that electrical components are protected from water.

When the furnace is installed so that supply ducts carry air circulated by the furnace to areas outside of the space conĆ taining the furnace, return air shall be handled by a duct(s) sealed to the furnace casing and terminating out-side space containing furnace.

WARNING

Product contains fiberglass wool.

Disturbing the insulation in this product during installation, maintenance, or repair will expose you to fiberglass wool dust. Breathing this may cause lung cancer. (Fiberglass wool is known to the State of California to cause cancer.)

Fiberglass wool may also cause respiratory, skin, and eye irritation.

To reduce exposure to this substance or for further information, consult material safety data sheets available from address shown below, or contact your supervisor.

Lennox Industries Inc.

P.O. Box 799900

Dallas, TX 75379-9900

NOTE - G26 series units must not be used as a construcĆ tion heater during any phase of construction. Very low return air temperatures, harmful vapors and misplacement of the filters will damage the unit and lower its efficiency.

General

These instructions are intended as a general guide and do not supersede local codes in any way. Consult authorities having jurisdiction before installation.

Page 4

Shipping and Packing List

1 - Assembled G26 furnace

1 - Bag assembly containing

1 - Electrical make-up box

1 - Wiring harness

1 - Snap bushing

2 - Filter clips

1 - 3 inch x 2 inch vent transition piece (-100, -125 units only)

1 - Adapter

1 - Condensate plug

1 - Nipple

1 - Brown accessory wire

1 - Green ground wire

3 - Wire nuts

2 - Star washers

Shipping Damage

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

WARNING

Improper installation, adjustment, alteration, service or maintenance can cause property damage, personĆ al injury or loss of life. Installation and service must be performed by a qualified installer, 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.

Installation - Setting Equipment

Select a location that allows for required clearances listed on the unit rating plate. Also consider gas supply connections, electrical supply, vent connection and installation and service clearances [24 inches (610 mm) at unit front]. The furnace must be level.

NOTE - 1/3 and 1/2 hp blower motors are equipped with eiĆ ther four flexible mounting legs or three flexible legs and one rigid leg. 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). This shipping bolt and flat washer must be removed before the furnace is put into operation. Once the shipping bolt and washer are removed, the rigid leg will not touch the blower housing.

CAUTION

G26 unit should not be installed in areas normally subject to freezing temperatures.

Page 5

Return Air Opening Guidelines

WARNING

Blower door 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.

WARNING

Improper installation of unit can result in personal inĆ jury or death. Combustion and flue 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 furĆ nace should be sealed airtight to the return air pleĆ num. 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. AlĆ low absolutely no sagging, cracks, gaps, etc.

For no reason should return and supply air duct sysĆ tems ever be connected to or from other heat-ing deĆ vices such as a fireplace or stove, etc. Fire, exploĆ sion, carbon monoxide poisoning, personal injury and/or property damage could result.

Return air can be brought in either side or at the bottom of the unit. Scribe lines show the outline of each side and the bottom return air opening.

Bottom Return Air Applications

If cold air return is to terminate through the floor under the furnace, a direct, airtight and sealed connection must be made to the bottom of the furnace.

1 - Cut opening in floor or platform. Using knockouts proĆ vided, cut bottom of base panel. See figure 2.

KNOCKOUT PATTERN FOR BOTTOM

RETURN AIR APPLICATION

FIGURE 2

2 - Bend a flange on return air plenum and lower into floor or platform opening. See figure 3.

3 - Position unit over return air opening. Seal unit air tight with return air plenum.

BOTTOM RETURN AIR APPLICATION

G26 UNIT

PROPERLY

SIZED FLOOR

OPENING

SUPPLY AIR

PLENUM

FIGURE 3

NOTE - Be careful not to damage glass fiber insulation.

Check for tight seal.

Side Return Air Applications

For installations where the return air is taken from a return air drop, unit may be installed using either the left or right side of furnace.

For side return air applications, cut furnace cabinet at the dimensions given on page 2. Embossed corners are proĆ vided on both cabinet sides for return air opening location.

Filters & Optional Filter Assembly

This unit is not equipped with a filter. Filter racks and reusable foam filters are available from Lennox in single kits (44J20 for 14 x 25 filters; 44J21 for 20 x 25 filters) or

10-pack kits (66K61 for 14 x 25 filters; 66K62 for 20 x 25 filters). A filter must be in place anytime the unit is in opĆ eration.

Bottom Return Air Applications

1 - Remove blower access panel.

2 - Install filter clips, provided with unit, by slipping folded section of clip on edge of bottom opening. See figure 4.

3 - Place filter in bottom of blower compartment beneath rear filter clip. Press down on filter sides. Filter clips flex allowing filter to snap into place.

4 - To remove filter, press clip and pull filter up and out.

BOTTOM RETURN FILTER INSTALLATION

REAR FILTER CLIP

FURNACE

BACK

SIDE FILTER CLIPS (2)

RETURN AIR OPENING

FURNACE

FRONT

FIGURE 4

FURNACE

BASE BOTTOM

Side Return Air Applications

An external filter rack, ordered separately, is available from

Lennox.

NOTE - The filter door may be shipped in the rack behind the filter. If necessary, remove the filter, retrieve the door and continue with the installation of the rack.

1 - Align filter rack opening with the inside edge of the side return opening. Bottom of rack should be approxiĆ mately 1 inches (25mm) from the bottom and 3 inch-es

(76mm) from the front of the unit.

2 - Screw filter rack into place with the eight self-drilling, self-tapping screws provided. See figure 5.

3 - Push filter door pins through the two holes in filter door from the inside of the u-channel. See figure 6.

4 - Position filter door on end of filter so that the thumb tab side of the filter door is away from the furnace. Squeeze thumb tabs to secure filter to door.

SIDE RETURN FILTER INSTALLATION

BLOWER DECK

RETURN

AIR

OPENING

12 in. (305) for

14 in. (356) Filter

18 in. (457) for

20 in. (508) Filter

RETURN AIR

PLENUM SIZE

12-3/4 in. X 23-1/2 in. (324 X 597) for 14 in. (356) Filter

18-3/4 in. x 23-1/2 in. (476 x 597) for 20 in. (508) Filter

1-15/16 in.

(49)

CABINET BASE BOTTOM

FIGURE 5

15/16 in.

(24)

FILTER DOOR ASSEMBLY

FILTER DOOR

PINS

TAB

FILTER DOOR

FILTER

FILTER DOOR

PIN

TAB

FIGURE 6

5 - Guide filter and filter door into the filter rack installed on side of furnace. Push door into filter rack until secure.

6 - To remove filter, pull filter door pins until door is released from filter rack.

Page 6

Duct System

Use industry-approved standards 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.

Supply Air Plenum

Furnaces installed without a cooling coil require the installaĆ tion of a removable access panel in the supply air duct. The access panel should be large enough to permit inspection (eiĆ ther by smoke or reflected light) of the heat exchanger for leaks after installation. The furnace access panel must always be in place when the furnace is operating and it must not allow leaks into the supply air duct system.

Return Air Plenum

See dimension illustration on page 2 for proper return air duct size.

NOTE - For bottom return air, return air duct should be seĆ cured to the unit using rivets or SĆlocks. For side return air, secure return air duct to filter rack using screws. When usĆ ing screws, take care to avoid interference with the filter which may cause improper filtration.

The return air must not be drawn from a room where another gas appliance (ie., a water heater) is installed.

Even though this furnace draws its combustion air from outside of the structure, other gas appliances that share a utility room may not. When return air is drawn from a room, a negative pressure is created in the room. If a gas apĆ pliance 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 monĆ oxide gas. This toxic gas might then be distributed through the house by the furnace duct system.

Pipe & Fittings Specifications

CAUTION

Solvent cements for plastic pipe are flammable liqĆ uids 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 fire hazard and to minimize breathing of solvent vapors. Avoid contact of ceĆ ment with skin and eyes.

All pipe, fittings, primer and solvent cement must conĆ form with American National Standard Institute and the

American Society for Testing and Materials (ANSI/

ASTM) standards. The solvent shall be free flowing and contain no lumps, undissolved particles or any foreign matter that adversely affects the joint strength or chemiĆ cal resistance of the cement. The cement shall show no gelation, stratification, or separation that cannot be reĆ moved by stirring. Refer to the table 2 below for approved piping and fitting materials.

TABLE 2

PIPING AND FITTINGS SPECIFICATIONS

PIPE & FITTING MATERIAL

ASTM

SPECIFICATION

Schedule 40 PVC (Pipe)

Schedule 40 PVC (Cellular Core Pipe)

Schedule 40 PVC (Fittings)

Schedule 40 CPVC (Pipe)

Schedule 40 CPVC (Fittings)

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

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

Schedule 40 ABS (Pipe)

Schedule 40 ABS (Fittings)

ABS-DWV (Drain Waste & Vent)

(Pipe & Fittings)

PVC-DWV (Drain Waste & Vent -

Pipe & Fittings)

D1785

F891

D2466

F441

F438

D2241

F442

D1527

D2468

D2661

D2665

NOTE - When a WTKX termination kit (30G79) is installed as part of the intake and exhaust piping, add twelve feet to the equivalent length of the pipe (the two 2 inch diameter

90° elbows and the 27 inch pipe in the kit).

Primers and solvents must meet ASTM specifications. PVC primer is specified in ASTM F 656. Use PVC solvent cement as specified in ASTM D 2564 and ABS solvent cement as specified in ASTM D 2235. Low temperature solvent cement is recommended. Metal or plastic strapping may be used for vent pipe hangers.

Table 3 lists the available exhaust termination kits. All LenĆ nox vent terminations are PVC.

Lennox Part No.

60G77

33K97

15F75

22G44

15F74

44J41

44J40

30G28

30G79

TABLE 3

TERMINATION KITS

Kit LB#

LB-49107CE

LB-87942

LB-49107CC

LB-49107CD

Description-Inches (mm)

2" (50.8) Concentric

Termination Kit

2" (50.8) Low Pressure Drop

Concentric Term. Kit

2" (50.8) Roof

Termination Kit

2" (50.8) Wall

Assembly Termination Kit

LB-49107CB

LB-65678A

LB-65701A

WTK

WTKX

2" (50.8) Wall Ring Kit

3" (76.2) Roof

Termination Kit

3" (76.2) Wall

Assembly Termination Kit

2" (50.8) Wall

Termination Extended Vent

2" (50.8) Wall

Termination Extension Riser

When making ABS joints, pieces can be prepared with a cleaner. When joining ABS to PVC materials, use PVC solĆ vent cement. Refer to this procedure as specified in ASTM

D3138.

Page 7

Vent Piping Guidelines

Pipe used for exhaust and intake lines should be sized acĆ cording to table 4. Note that maximum length of vent pipe is for one run; either intake or exhaust. Maximum vent length given is not the total length of intake + exhaust vents.

Each 90° elbow is equivalent to 5 feet (1.52m) of vent pipe.

Two 45° elbows are equivalent to one 90° elbow. One

45°elbow is equal to 2.5 feet (.76m) of vent pipe.

If intake and exhaust piping runs are not equal in length and number of elbows, the larger diameter pipe must be used for both runs.

TABLE 4

VENT PIPE SIZING TABLE FOR G26 FURNACES

MINIMUM DIAMETER OF INTAKE/EXHAUST PIPE

Vent Pipe

Equivalent Length

Max. Feet (Meters)

G26-50

50,000

BTU

G26-75

75,000

BTU

G26-100

100,000

BTU

G26-125

125,000

BTU

15 (4.57m)

20 (6.10m)

25 (7.62m)

30 (9.14m)

40 (12.19m)

50 (15.24m)

55 (16.76m)

60 (18.29m)

70 (21.34m)

80 (24.38m)

90 (27.43m)

100 (30.48m)

110 (33.53m)

120 (36.58m)

130 (39.62m)

3"

3"

3"

3"

3"

3"

2"

2"

2"

3"

3"

3"

3"

3"

3"

2"

2"

2"

2"

3"

3"

2"

2"

2"

3"

3"

3"

3"

3"

3"

1-1/2"

2"

2"

2"

2"

2"

2"

3"

3"

3"

3"

3"

3"

3"

3"

3"

3"

3"

3"

3"

3"

2"

3"

3"

3"

3"

3"

3"

3"

--

NOTE - M inch pipe for G26-50 is 5 feet and 2 elbows of 1.5 inch diameter pipe.

NOTE - M inch pipe for G26-75 is 5 feet and 2 elbows of 2 inch diameter pipe.

NOTE - M inch pipe for G26-100 is 5 feet and 2 elbows of 2 inch diameter pipe.

NOTE - M inch pipe for G26-125 is 5 feet and 2 elbows of 2 inch diameter pipe.

NOTE - When a WTKX termination kit is installed as part of the intake and exhaust piping, the two 2 inch diameter 90° elbows and the 27 inch pipe (in the kit) should be included in the maximum vent pipe length for each run.

For -50 and -75 kBtuh units, connections are provided for 2 inch diameter venting which should satisfy most venting reĆ quirements. No transition pieces are provided or needed for 2 inch venting.

For -100 and -125 kBtuh units, the intake connection is sized for 3 inch diameter pipe. The exhaust connection has a 2 inch nipple. A pipe transition piece is shipped with the unit to connect to 3 inch pipe. See figure 7 for 2 inch and 3 inch venting applications.

Most venting applications will require 3 inch venting for proper unit operation. For no reason should the intake and exhaust pipe be different diameter pipes. RegardĆ less of the diameter of pipe used, the standard roof and wall terminations described in section Intake and Exhaust PipĆ ing Terminations should be used. Exhaust piping must terĆ minate with 1-1/2 inch pipe for 1-1/2 inch or 2 inch venting and 2 inch pipe for 3 inch venting.

G26-100 OR -125 WITH 2 IN. VENTING

2 IN. VENT PIPE

3 IN. X 2 IN.

REDUCER

3 IN. FIELD

PROVIDED

NIPPLE

2 IN

OUT

3 IN.

IN

G26-100 OR -125 WITH 3 IN. VENTING

3 IN. X 2 IN.

REDUCER

2 IN. FIELD

PROVIDED

NIPPLE

3 IN. VENT PIPE

2 IN.

OUT

3 IN.

IN

FIGURE 7

Joint Cementing Procedure

All cementing of joints should be done according to the specifications outlined in ASTM D 2855.

WARNING

DANGER OF EXPLOSION! Fumes from pvc glue may ignite during system check. Remove spark plug wire from ignition control before 115v power is applied.

Reconnect wire after two minutes.

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 fitting socket and result in a leaking joint.

3 - Clean and dry surfaces to be joined.

4 - Test fit joint and mark depth of fitting on outside of pipe.

5 - Uniformly apply liberal coat of PVC primer for PVC or

ABS cleaner for ABS to inside socket surface of fitting and male end of pipe to depth of fitting socket.

6 - Promptly apply solvent cement to end of pipe and inside socket surface of fitting. 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.

Page 8

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

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 pipe 1/4 turn during asĆ sembly (but not after pipe is fully inserted) to distribute cement evenly.

NOTE-Assembly should be completed within 20 secĆ onds 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 fitting socket. A properly made joint will show a bead around its entire perimeter. Any gaps may indiĆ cate a defective assembly due to insufficient solvent.

9 - Handle joints carefully until completely set.

Venting Practices

The thickness of construction through which vent/air intake pipes may be installed is a minimum of 3 inches (610 mm), and a maximum of 24 inches (610mm). If a G26 furnace replaces 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 reĆ maining appliance.

WARNING

Insufficient combustion air can cause headaches, nausea, dizziness or asphyxiation. It will also cause excess water in the heat exchanger resulting in rustĆ ing 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 comĆ bustion 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

Intake Piping

1 - Cement intake piping in slip connector located at top of unit.

2 - Route piping to outside of structure. Continue with installation following instructions given in exhaust and intake piping termination section.

Exhaust Piping

1 - Cement exhaust piping into flue collar socket located on the left side of the top cap.

2 - All horizontal runs of exhaust pipe must slope back toward unit. A minimum of a 1/4 inch (6mm) drop for each

12 inches (305mm) of horizontal run is mandatory for drainage. Horizontal runs of exhaust piping must be supported every 5 feet (1.52m) using hangers.

NOTE - Exhaust piping should be checked carefully to make sure there are no sags or low spots.

NOTE - Exhaust piping must be insulated with 1/2 inch

(13mm) Armaflex or equivalent when run through unĆ heated space. Do not leave any area of exhaust pipe open to outside air; exterior exhaust must be insulated with 1/2 inch (13mm) Armaflex or equivalent.

CAUTION

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

CAUTION

The exhaust vent pipe operates under positive presĆ sure and must be completely sealed to prevent leakĆ age of combustion products into the living space.

Removal of Unit from Common Venting System

In the event that an existing furnace is removed from a venting system commonly run with separate gas apĆ pliances, the venting system is likely to be too large to propĆ erly vent the remaining attached appliances. The following test should be conducted while all appliances (both in opĆ eration and those not in operation) are connected to the common venting system. If the venting system has been installed improperly, corrections must be made as outlined in the previous section.

1 - Seal any unused openings in the common venting sysĆ tem.

2 - Visually inspect the venting system from proper size and horizontal pitch and determine there is no blockage or restriction, leakage, corrosion and other defiĆ ciencies which could cause an unsafe condition.

Page 9

3 - Close all building doors and windows and all doors beĆ 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 dryĆ ers 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 opĆ erate at maximum speed. Do not operate a summer exhaust fan. Close fireplace dampers.

4 - Follow the lighting instruction. Place the appliance beĆ ing inspected in operation. Adjust thermostat so apĆ pliance will operate continuously.

5 - Test for spillage at the draft hood relief opening after 5 minutes of main burner operation. Use the flame of a match or candle, or smoke from a cigarette, or a cigar.

6 - After you have determined that each appliance reĆ maining connected to the common venting system properly vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other gas-burning appliance to their previous conĆ dition of use.

7 - If improper venting is observed during any of the above tests, the common venting system must be corĆ rected. The common venting system should be resized 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 in the U.S.A., and the appropriate Category 1

Natural Gas and Propane appliances venting sizing tables in the current standards of the CAN/

CGA-B149.1 and .2 in the Natural Gas and Propane

Installation Code in Canada.

Intake and Exhaust Piping Terminations

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. Figures 8 through 20 show typical terĆ minations.

1 - Use recommended piping materials for both intake and exhaust piping.

2 - Secure all joints, including drain leg, gas tight using approved cement.

3 - Piping diameters should be determined according to length of pipe run. See table 4. Locate intake piping upwind (prevailing wind) from exhaust piping. To avoid re-circulation of exhaust gas on roof terminations, end of exhaust pipe must be higher than intake pipe.

Exhaust and intake exits must be in same pressure zone. Do not exit one through the roof and one on the side. Also, do not exit the intake on one side and the exhaust on another side of the house or structure.

Page 10

4 - Intake and exhaust pipes should be placed as close together as possible at termination end (refer to ilĆ lustrations). Maximum separation is 3 inches (76mm) on roof terminations and 6 inches (152mm) on side wall terminations.

5 - Exhaust piping must terminate straight out or up as shown. In rooftop applications, a 2 inch X 1-1/2 inch reĆ ducer for 2 inch venting, 3 inch x 2 inch reducer for 3 inch venting must be used on the exhaust piping at the point where it exits the structure to improve the velocity of exhaust away from the intake piping.

On roof terminations, the intake piping should termiĆ nate straight down using two 90° elbows (See figure 8).

IMPORTANT

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

NOTE - If winter design temperature is below 32°F (0°C), exhaust piping must be insulated with 1/2 inch (13mm),

Armaflex or equivalent when run through unheated space. Do not leave any surface area of exhaust pipe open to out-side air; exterior exhaust pipe must be insuĆ lated with 1/2 inch (13mm) Armaflex or equivalent. In exĆ treme cold climate areas, 3/4 inch (19mm) Armaflex or equivalent is recommended. Insulation on outside runs of exhaust pipe must be painted or wrapped to protect inĆ sulation from deterioration.

Inches(mm)

3(76) MAX.

3 x 2 (76 x 51) OR

2 x 1-1/2 (51 x 38)

PVC REDUCER

8 (203) MIN

12 (305) ABOVE

AVERAGE SNOW

ACCUMULATION

3 (76) OR

2 (51) PVC

PROVIDE SUPPORT

FOR INTAKE AND

EXHAUST LINES

1/2 (13) FOAM

INSULATION IN

UNCONDITIONED

SPACE

UNCONDITIONED

ATTIC SPACE

ROOF TERMINATION KIT

(15F75) LB-49107CC for 2 (51) Venting

(44J41) LB-65678A for 3 (76) Venting

FIGURE 8

NOTE - During extremely cold temperatures, below approximately 20°F (6.67°C), units with long runs of vent pipe through unconditioned space, even when insulated, may form ice in the exhaust termination that prevents the

unit from operating properly. Longer run times of at least 5 minutes will alleviate most icing problems. Also, a heating cable may be installed on exhaust piping and termination to prevent freeze-ups. Heating cable installation kit is available from Lennox. See Condensate Piping section for part numbers.

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

6 - On field supplied terminations for side wall exits, exĆ haust piping should extend a maximum of 12 inches

(305mm) beyond the outside wall. Intake piping should be as short as possible. See figure 9.

1/2 (13) ARMAFLEX

INSULATION IN

UNCONDITIONED SPACE

2 (51) PVC

1/2 (13) ARMAFLEX

INSULATION

12 (305) MIN.

2 X 1-1/2

(51 x 38)

PVC REDUCER

1-1/2 (38) PVC

6 (152)

MAXIMUM

2 (51) PVC

COUPLING

OUTSIDE

WALL

8 (203)

MINIMUM

Inches (mm) TOP VIEW

WALL RING KIT

(15J74) LB-49107CB for 2 (50.8) Venting

FIGURE 9

7 - On field supplied terminations, a minimum separation distance between the end of the exhaust pipe and the end of the intake pipe is 8 inches (203mm).

8 - If intake and exhaust piping must be run up a side wall to position above snow accumulation or other obĆ structions. Piping must be supported every 3 feet

(.91m) as shown in figure 15. Refer to figures 13 and

14 for proper piping method. WTK wall termination kit must be extended for use in this application. See figĆ ure 18 or use kit WTKX shown in figure 19. When exĆ haust and intake piping must be run up an outside wall, the exhaust piping is reduced to 1-1/2 inches

(38mm) after the final elbow. The intake piping may be equipped with a 90° elbow turndown. Using turnĆ down will add 5 feet (1.5m) to the equivalent length of the pipe.

1/2 (12.7) FOAM INSULATION

IN UNCONDITIONED SPACE

OUTSIDE WALL

Optional Turndown

Shown

(Intake Only)

TOP VIEW

WALL TERMINATION

(22G44) LB-49107CD for 2 (50.8) Venting

(44J40) LB-65701A for 3 (76.2) Venting

FIGURE 10

EXHAUST

TERMINATION

12 (305) ABOVE

AVERAGE SNOW

ACCUMULATION

INTAKE

TERMINATION

Inches(mm)

Inches (mm)

EXHAUST INTAKE

CONCENTRIC ROOFTOP TERMINATION

(60G77) LB-49107CE for G26-50 & -75 Units Only

(33K97) LB-87942 for G26-100 & -125 Units Only

FIGURE 11

EXHAUST

INTAKE

INTAKE

TERMINATION

12 (305) Min.

above grade.

Inches (mm)

CONCENTRIC WALL TERMINATION

(60G77) LB-49107CE for G26-50 & -75 Units Only

(33K97) LB-87942 for G26-100 & -125 Units Only

FIGURE 12

EXHAUST

TERMINATION

Page 11

Inches(mm)

UNCONDITIONED

SPACE

OUTSIDE WALL

PROVIDE SUPPORT

FOR INTAKE AND

EXHAUST LINES EVERY

36 (914)

12 (305) MIN. for 2 (51)

20 (508) MAX. for 3 (76)

8 (203)

MIN.

12 (305) ABOVE

AVERAGE SNOW

ACCUMULATION

1/2 (13) FOAM

INSULATION IN

UNCONDITIONED

SPACE

SIDE VIEW

WALL RING TERMINATION

1/2 (13) FOAM

INSULATION

(15F74) LB-49107CB for 2 in. (51) Venting

*This reducer is not necessary for G26-50 units using 1-1/2 in. venting.

See venting table 4 for maximum venting lengths with this arrangement.

FIGURE 13

IMPORTANT

Combustion air intake inlet and exhaust outlet should not be located within 6 feet (1.8m) of dryer vent or comĆ bustion air inlet or outlet of another appliance. Piping should not exit less than 3 feet (.91m) from opening into another building.

IMPORTANT

For Canadian Installations Only:

In accordance to CAN/CGA-B149.1 and .2, the miniĆ mum allowed distance between the combustion air intake inlet and the exhaust outlet of other apĆ pliances shall not be less than 12 inches (305mm).

Inches(mm)

1/2 (13)

FOAM

INSULATION

3 (76) OR

2 (51) 90° ELBOW

3 x 2 (76 x 51) OR

2 x 1-1/2 (51 x 38)

REDUCER BUSHING LOCATION

FOR OFFSET TERMINATION

9 - Position termination ends so they are free from any obĆ structions and above the level of snow accumulation

(where applicable). Termination ends must be a minimum of 12 inches (305mm) above grade level. Do not point into window wells, stairwells, alcoves, courtyard areas or other recessed areas. Do not position terminaĆ tion ends directly below roof eaves or above a walkway.

Since the G26 is a certified direct vent, Category IV gas furnace, the location of the termination is limited by loĆ cal building codes. In the absence of local codes, refer to the current National Fuel Gas Code ANSI Z223-1 in

U.S.A., and current standards CAN/CGA-B149.1 /.2 of the Natural Gas and Propane Installation Instructions in

Canada for details. The termination should be at least

12 inches (305mm) from any opening through which flue products could enter the building.

When horizontally vented, minimum clearance for terĆ mination from electric meters, gas meters, regulators and relief equipment is 4 feet (1.2m) for US installaĆ tions. Refer to the current CAN/CGA-B149.1 and .2 for installations in Canada or with authorities having local jurisdiction.

At vent termination, care must be taken to maintain protective coatings over building materials (proĆ longed exposure to exhaust condensate can destroy protective coatings). It is recommended that the exĆ haust outlet not be located within 6 feet (1.8m) of a condensing unit because the condensate can damĆ age the painted coating.

Optional Turndown

(Not Shown)

May Be Used on

Intake Only

3 (76) OR

2 (51) 90° ELBOW

FRONT VIEW

WALL TERMINATION

Inches (mm)

(22G44) LB-49107CD for 2(51) Venting

(44J40) LB-65701A for 3(76) Venting

METAL OR PLASTIC

STRAPPING

OR LARGE WIRE TIES

FIGURE 14

FIGURE 15

10 - Suspend piping using hangers at a minimum of every

5 feet (1.52m) for schedule 40 PVC and every 3 feet

(.91m) for ABS-DWV, PVC-DWV, SPR-21 PVC, and

SDR-26 PVC piping. A suitable hanger can be fabriĆ cated by using metal or plastic strapping or a large wire tie.

11 - 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.

12 - Isolate piping at the point where it exits the outside wall or roof.

Page 12

13 - 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 condenĆ sate collection trap and lines.

14 - Based on the recommendation of the manufacturer, a multiple furnace installation may use a group of up to four termination kits WTK assembled together horizontally, as shown in figure 17.

Front View 12

(305)

COVER EXHAUST

VENT WITH

1/2 (13)

FOAM

INSULATION

INTAKE

AIR

5

(127)

EXHAUST

AIR

12 MIN.

(305)

Above Grade

5Ć1/2

(140)

GRADE

ÉÉÉÉÉÉÉÉÉ

INTAKE

AIR

EXHAUST

AIR

Side View

8 (203)

Minimum Inches (mm)

Front View

INTAKE

VENT

1/2 (13) Foam

Insulation in

Unconditioned Space

12

(305)

EXHAUST VENT

5

(127)

Side View

EXHAUST VENT

Inches (mm)

INTAKE VENT

OUTSIDE WALL

VENT TERMINATIONS

WALL TERMINATION KIT (30G28) WTK

FIGURE 16

Front View

Side View

EXHAUST

VENT

INTAKE VENT

5

(127)

5-1/2

(140)

12

(305)

18 MAX.

(457)

EXHAUST VENT

Inches (mm) INTAKE

VENT

OPTIONAL VENT TERMINATION FOR

MULTIPLE UNIT INSTALLATION

WALL TERMINATION KIT WTK

FIGURE 17

12 (305)

Minimum

ABOVE GRADE

GRADE

ÉÉÉÉÉÉÉÉÉÉÉ

VENT TERMINATIONS

MODEL WTK WALL TERMINATION KIT (30G28)

EXTENDED VENT FOR GRADE CLEARANCE

FIGURE 18

9

(229)

Front View

34

(864)

INTAKE

VENT

EXHAUST

VENT

NOTE-Enclosed exhaust pipe is insulated with 1/2 in. (13mm) foam insulation. If intake and exhaust pipes are reversed, slit and remove foam insulation and reapply to other vent. ExĆ haust vent must be insulated.

Side View

4

(102)

12

(305)

GRADE

EXHAUST VENT

8 MIN.

(203)

INTAKE

VENT

GRADE

VENT TERMINATIONS

MODEL WTKX (30G79)

EXTENSION RISER FOR GRADE CLEARANCE

FIGURE 19

Page 13

G26 VENTING IN EXISTING CHIMNEY

8 in. - 12 in.

(203mm - 305mm)

3 in. - 8 in.

(76mm-

203mm)

3 in. - 8 in.

(76mm-

203mm)

NOTE-Do not discharge exhaust gases directly into any chimney or vent stack. If vertiĆ cal discharge through an existing unused chimney or stack is required, insert piping inside chimney until the pipe open end is above top of chimney and terminate as illusĆ trated. In any exterior portion of chimney, the exhaust vent must be insulated. An alterĆ nate method is to fill the chimney with vermiculite or equal to take advantage of its acoustic and thermal properties.

FIGURE 20

Condensate Piping

This unit is designed for either right- or left-side exit of conĆ densate piping. Condensate drain line should be routed only within the conditioned space to avoid freezing of conĆ densate and blockage of drain line. An electric heat cable should be used where condition is exposed to uncondiĆ tioned areas.

CAUTION

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

1 - Determine which side condensate will exit the unit.

2 - Connect a 1/2 inch (13mm) plastic pipe plug (provided) in the unused end of the condensate trap. Install plug so that it is sealed water tight yet able to be removed. Do not permanently seal the connection. Teflon tape is recĆ ommended to seal joint. See figure 21.

CONDENSATE ASSEMBLY

(For left or right installation)

COMBUSTION AIR

INDUCER BRACKET

COLD HEADER

BOX

3 - Use the provided adapter (1/2 inch PVC x 1/2 inch

MPT) and the nipple (1/2 inch PVC) to carry drainage outside the cabinet. If a field substitute is needed, 1/2 inch CPVC x 1/2 inch MPT adapter and 1/2 inch CPVC is acceptable for use.

4 - Glue nipple to the adapter using the procedures outlined in the Joint Cementing Procedures" section.

The nipple/adapter assembly should be connected in a non-permanent manner and must be water tight.

Teflon tape is recommended to seal the joint.

For Right-Hand Side Condensate Exit:

Install the nipple/adapter assembly from the outside of the cabinet and insert the adapter into the threaded opening in the condensate trap.

For Left-Hand Side Condensate Exit:

Insert nipple/adapter assembly from the left hand side of the cabinet and through the combustion air inducer mounting structure into the threaded openĆ ing in the condensate trap.

5 - Connect field supplied plumbing to nipple and route to open drain. Plumbing should be vented to a point higher than the condensing coil. See figure 22.

CONDENSATE PLUMBING

(Plumbing must be vented higher than coil.)

NIPPLE

ADAPTER

CONDENSATE TRAP

NIPPLE

ADAPTER

PLUG BOOT OR CAP

FIGURE 21

FIGURE 22

6 - Connect condensate drain line (1/2 inch [13mm] SDR

11 plastic pipe or tubing) to condensate connection on drip leg assembly and route to open drain. Condensate line must be sloped downward away from drip leg to drain. If drain level is above drip leg, condensate pump must be used to condensate line. 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

Page 14

used on the condensate drip leg and line. Heating cable kit is available from Lennox in various lengths;

6feet (1.8m) - kit no. 18K48; 24 feet (7.3m) - kit no.

18K49; and 50 feet (15.2m) - kit no. 18K50.

Gas Piping

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 bottom of the valve as shown in figure 23.

LEFT SIDE PIPING

MANUAL

MAIN SHUT-

OFF

VALVE

1/8 IN. NPT

PLUGGED

TAP

GAS VALVE

RIGHT SIDE PIPING

(STANDARD)

MANUAL

MAIN SHUT-

OFF

VALVE

1/8 IN. NPT

PLUGGED

TAP

GAS VALVE

FIGURE 23

2 - When connecting the gas supply, factors such as length of run, number of fittings and furnace rating must be considered to avoid excessive pressure drop

Table 5 lists recommended pipe sizes for typical applications.

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

3 - The gas piping must not run in or through air ducts, clothes chutes, gas vents or chimneys, dumb waiters or elevator shafts. Center gas line through piping hole.

Gas line should not touch side of unit.

When left-hand gas plumbing is required, gas line should be installed in the lower half of knockout so that piping will clear combustion air inducer. See figure 23.

4 - The piping should be sloped 1/4 inch (6.4 mm) per 15 feet (4.57 m) upward toward the meter from the furĆ nace. The piping must be supported at proper interĆ vals [every 8 to 10 feet (2.44 to 3.01 m)] using suitable hangers or straps. A drip leg should be installed in verĆ tical pipe runs to the unit.

5 - In some localities, codes may require installation of a manual main shut-off valve and union (furnished by inĆ staller) external to the unit. 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 petroĆ leum gases.

MANUAL MAIN SHUT-OFF

NORMAL TEST PRESSURE

1/8 IN. (3.2mm) N.P.T.

PLUGGED TAP

CAP

FURNACE

FIGURE 24

NOTE - Install a 1/8 inch NPT plugged tap in the field pipĆ ing upstream of the gas supply connection to the unit.

The tap must be accessible for test gauge connection.

See figure 24.

Leak Check

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

CAUTION

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

Page 15

Nominal

Iron Pipe Size

-Inches(mm)

Internal

Diameter

-Inches(mm)

10

(3.048)

TABLE 5

GAS PIPE CAPACITY - FT 3 /HR (kL/HR)

20

(6.096)

30

(9.144)

40

(12.192)

Length of Pipe-Feet(m)

50

(15.240)

60

(18.288)

70

(21.336)

80

(24.384)

1/4

(6.35)

3/8

(9.53)

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)

4

(101.6)

.364

(9.246)

.493

(12.522)

.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)

4.026

(102.260)

43

(1.13)

95

(2.69)

175

(4.96)

360

(10.19)

680

(19.25)

1400

(39.64)

2100

(59.46)

3950

(111.85)

6300

(178.39)

11000

(311.48)

23000

(651.27)

29

(.82)

65

(1.84)

120

(3.40)

250

(7.08)

465

(13.17)

950

(26.90)

460

(41.34)

2750

(77.87)

4350

(123.17)

7700

(218.03)

15800

(447.39)

24

(.68)

52

(1.47)

97

(2.75)

200

(5.66)

375

(10.62)

770

(21.80)

1180

(33.41)

2200

(62.30)

3520

(99.67)

6250

(176.98)

12800

(362.44)

20

(.57)

45

(1.27)

82

(2.32)

170

(4.81)

320

(9.06)

660

(18.69)

990

(28.03)

1900

(53.80)

3000

(84.95)

5300

(150.07)

10900

(308.64)

18

(.51)

40

(1.13)

73

(2.07)

151

(4.28)

285

(8.07)

580

(16.42)

900

(25.48)

1680

(47.57)

2650

(75.04)

4750

(134.50)

9700

(274.67)

16

(.45)

36

(1.02)

66

(1.87)

138

(3.91)

260

(7.36)

530

(15.01)

810

(22.94)

1520

(43.04)

2400

(67.96)

4300

(121.76)

8800

(249.18)

NOTE-Capacity given in cubic feet of gas per hour (kilo liters of gas per hour) and based on 0.60 specific gravity gas.

15

(.42)

33

(.73)

61

(1.73)

125

(3.54)

240

(6.80)

490

(13.87)

750

(21.24)

1400

(39.64)

2250

(63.71)

3900

(110.43)

8100

(229.36)

14

(.40)

31

(.88)

57

(1.61)

118

(3.34)

220

(6.23)

460

(13.03)

690

(19.54)

1300

(36.81)

2050

(58.05)

3700

(104.77)

7500

(212.37)

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

90

(27.432)

13

(.37)

29

(.82)

53

(1.50)

110

(3.11)

205

(5.80)

430

(12.18)

650

(18.41)

1220

(34.55)

1950

(55.22)

3450

(97.69)

7200

(203.88) tion purposes. Refer to figure 29 for control box arrangeĆ ment, figure 30 for a detail of the Surelightt integrated control, figure 31 for schematic wiring diagram and trouĆ bleshooting, and figure 32 for point to point field wiring.

ELECTROSTATIC DISCHARGE (ESD)

Precautions and Procedures

100

(30.480)

12

(.34)

27

(.76)

50

(1.42)

103

(2.92)

195

(5.52)

400

(11.33)

620

(17.56)

1150

(32.56)

1850

(52.38)

3250

(92.03)

6700

(189.72)

IMPORTANT

When testing pressure of gas lines, gas valve must be disconnected and isolated. See figure 24. Gas valves can be damaged if subjected to pressures greater than 1/2 psig (3.48 kPa).

Electrical

A field make-up box is provided for line voltage wiring. Line voltage wiring to unit is done through the J69 jack from the field make-up box to plug P69 from the control box. See figĆ ures 25 and 26 for make-up box installation.

Figure 28 shows thermostat designations for identificaĆ

CAUTION

Electrostatic discharge can affect electronic comĆ ponents. Take precautions during furnace installaĆ tion and service to protect the furnace's electronic controls. Precautions will help to avoid control exĆ posure to electrostatic discharge by putting the furĆ nace, the control and the technician at the same electrostatic potential. Neutralize electrostatic charge by touching hand and all tools on an unĆ painted unit surface, such as the gas valve or blowĆ er deck, before performing any service procedure.

1 - Install field make-up box on either side, inside or out of the cabinet. Knockouts are provided in box and cabiĆ net to run wiring. See figures 25 and 26.

Page 16

INTERIOR MAKE-UP BOX INSTALLATION

MAKE-UP

BOX

BUSHING

J69

P69 from

Control Box

FIGURE 25

EXTERIOR MAKE-UP BOX INSTALLATION

MAKE-UP

BOX

BUSHING

J69

(Shown with accessory wire connected)

P69 from

Control Box

FIGURE 26

2 - Remove cap from knockout in blower deck on the same side as the installed make-up box.

IMPORTANT

Ignition control will not operate unless unit is properĆ ly grounded. 120V supply must be installed with corĆ rect polarity.

3 - Electrically ground unit in accordance with local codes or, in the absence of local codes, in accordance with the current National Electric Code (ANSI/NFPA No.

70) and in Canada with the current Canadian Electric

Code part 1 (CSA standard C22.1). The ground wire is pro-vided in the field make-up box.

To ensure proper grounding of the furnace, two star washers are included in the electrical make-up box bag assembly. Place the star washer on securing screw before installing the make-up box. Make sure the star washer breaks the paint on the cabinet so that the washer is touching metal. Unit is not properly grounded if paint has not been removed by star washer.

4 - An optional 120 volt accessory wire is provided with

G26 units. Install brown accessory wire into J69 jack plug by inserting the pin of the brown wire into the open socket of the jack. See fig-

INSTALLING BROWN

ACCESSORY WIRE TO J69 ure 27. Any accessory rated up to 4 amps can be connected to this wire. Connect the neutral leg of the accesĆ sory to the neutral white wire in the make-up box. The acĆ cessory terminal is enerĆ gized whenever the blower is in operation.

5 - Insert the three-pin (P69)

WHITE

NEUTRAL

BLACK

J69

BROWN plug from the control box

FIGURE 27 into the knockout provided in the blower deck.

6 - Connect jack (J69) from make-up box to jack plug in blower deck.

7 - Select wire size according to the blower motor amps.

8 - Snaphole bushing is provided for the wiring entry hole in the cabinet. A snaphole plug is provided to seal the unused wire entry hole.

9 - Install room thermostat according to instructions provided with thermostat. See figure 28 for thermostat desĆ ignations. If furnace is being used with heat pump refer to FM21 installation instruction.

10 - Install a separate fused disconnect switch near the unit so power can be turned off for servicing.

G26 and CONDENSING UNIT

THERMOSTAT DESIGNATIONS

(Refer to specific thermostat and outdoor unit.)

Thermostat G26

Furnace

Condensing Unit

Y

COOLING

Y

COMPRESSORā

HS UNIT

COMPRESSOR

INDOOR BLOWER

HEAT

W W

POWER

COMMON COMMON

HS UNIT

COMMON

FIGURE 28

11 - Complete wiring connections to equipment using wirĆ ing diagrams provided with unit and in figures 31 and

32. Use 18-gauge wire or larger for thermostat conĆ nections.

Page 17

Indoor Blower Speeds (Refer to Figure 31)

1 - When the thermostat is set to FAN ON," the indoor blower will run continuously on low speed when there is no cooling or heating demand.

2 - When there is a cooling demand, the indoor blower will run on the cooling speed.

3 - When there is a heating demand, the indoor blower will run on the heating speed.

G26 CONTROL BOX

TRANSFORMER

CIRCUIT

BREAKER

DOOR

INTERLOCK

SWITCH

SURELIGHT

CONTROL

FIGURE 29

DETACHABLE

TERMINAL STRIP

2

SURELIGHT INTEGRATED CONTROL BOARD

ACB COOL

ACB HEAT

PARK

ACB LOW

ACC

TX

HOT

HTG ACC

NEUTRALS

24VAC HOT

24VAC RTN

FLAME SENSE

TERMINAL DESIGNATIONS

Blower - Cooling Speed (Line Volt)

Blower - Heating Speed (Line Volt)

Alternate Blower Speeds (Dead)

Continuous Low Speed Blower

Accessory Terminal (Line Volt)

120VAC Hot to Transformer

120VAC Hot Input

Heat Only Accessory (Line Volt)

120VAC Neutrals

24VAC Hot from Transformer

24VAC Return from Transformer

Flame Sense Terminal

FIGURE 30

Page 18

OUTDOOR

UNIT

TYPICAL G26 WIRING DIAGRAM

B6

COMBUSTION

AIR INDUCER

MOTOR

FIGURE 31

Page 19

THERMOSTAT

W R Y G

TYPICAL G26 FIELD WIRING DIAGRAM

FLAME

ROLLOUT

SWITCH

COMBUSTION

AIR PROVE

SWITCH

LIMIT IGNITION

CONTROL

FIELD

MAKE-UP

BOX

GAS

VALVE

COMBUSTION

AIR INDUCER

J69

BLACK

WHITE

BROWN

TRANSFORMER

L1 N GND

Y G W R

SURELIGHT CONTROL

C

CONTROL

BOX

DOOR

INTERLOCK

SWITCH

TO ACCESSORY IF USED.

(ELECTRONIC AIR CLEANER)

IF NOT NEEDED, DO NOT INSTALL

ACCESSORY WIRE IN J69.

TO COMPRESSOR

CONTACTOR

FIELD INSTALLED CLASS II 24V VOLTAGE

FIELD INSTALLED LINE VOLTAGE

Unit Start-Up

FOR YOUR SAFETY READ BEFORE LIGHTING

WARNING

Do not use this furnace if any part has been underwaĆ ter. Immediately call a qualified service technician to inspect the furnace and to replace any part of the control system and any gas control which has been under water.

FIGURE 32

Gas valve may be equipped with either a gas control knob or lever. Use only your hand to push in or turn the gas conĆ trol knob or move the gas control lever. Never use tools. If the knob will not push in or turn or if lever will not move by hand, do not try to repair it, call a qualified service techniĆ cian. Force or attempted repair may result in a fire or exploĆ sion.

G26 units are equipped with a SureLightt ignition sysĆ tem. Do not attempt to manually light burners on this furĆ nace. 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 SureLightt ignition system.

Gas Valve Operation (Figure 33) WARNING

If overheating occurs, or if gas supply fails to shut off, shut off the manual gas valve to the appliance beĆ fore shutting off electrical supply.

WARNING

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

CAUTION

Before attempting to perform any service or mainteĆ nance, turn the electrical power to unit OFF at disĆ connect switch.

BEFORE OPERATING 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.

1 - STOP! Read the safety information at the beginning of this section.

2 - Set thermostat to lowest setting.

3 - Turn off all electrical power to furnace.

4 - This furnace is equipped with an ignition device which automatically lights the burner. Do not try to light the burners by hand.

5 - Remove the unit access panel.

Page 20

HONEYWELL VR8205 SERIES GAS VALVE

ON

OFF

GAS VALVE SHOWN IN OFF POSITION

WHITE RODGERS

36E GAS VALVE

GAS VALVE

SHOWN

IN OFF

POSITION

FIGURE 33

6 - White Rodgers 36E Gas Valve - Switch gas valve leĆ ver to OFF. See figure 33.

Honeywell VR8205 Gas Valve - Turn knob on gas valve clockwise to OFF. Do not force. See figure

33.

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 instrucĆ tions. If you do not smell gas go to next step.

8 - White Rodgers 36E Gas Valve - Switch gas valve lever to ON.

Honeywell VR8205 Gas Valve - Turn knob on gas valve counterclockwise to ON. Do not force.

9 - Replace unit access panel.

10- Turn on all electrical power to unit.

11- Set thermostat to desired setting.

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

NOTE - On initial start-up and when condensate trap is dry, unit may turn itself off and on to allow condensate trap to fill. This is normal operation.

12- If the furnace will not operate, follow the instructions

To Turn Off Gas To Unit" and call your service techniĆ cian or gas supplier.

To Turn Off Gas To Unit

1 - Set thermostat to lowest setting.

2 - Turn off all electrical power to unit if service is to be perĆ formed.

3 - Remove heat section access panel.

4 - On Honeywell VR8205 gas valves, turn knob on gas valve clockwise to OFF. For White Rodgers 36E gas valves, move switch to OFF. Do not force.

5 - Replace the unit access panel.

Gas Pressure Adjustment

Gas Line Pressure

Check gas line pressure with unit firing at maximum rate. A minimum of 4.5 inches w.c. (1.12kPa) for natural gas or 8.5

inches w.c. (2.11kPa) for LP/propane gas should be mainĆ tained.

Gas Manifold Pressure

After line pressure has been checked and adjusted, check regulator pressure. See table 6 for correct manifold presĆ sures for LP/propane and natural gas at altitudes in a range of 0 to 7500 feet (0 to 2248m).

TABLE 6

Unit (Fuel)

Manifold Pressure (outlet) from 0 to 7500 ft. (0 to 2248m) above sea level

Natural

L.P./Propane

3.5" w.c. (.87 kPa)

7.5" w.c. (1.86 kPa)

WARNING

Do not set manifold pressure for LP/propane higher than 7.5 inches w.c. (1.8kPa).

HONEYWELL GAS VALVE

GAS VALVE

CONTROL KNOB

WIRING

TERMINALS

INLET

PRESSURE

TAP

OUTLET

PRESSURE

TAP

OUTLET

FIGURE 34

BARBED

FITTING FOR

PRESSURE

SWITCH

HOSE

PRESSURE

REGULATOR

(UNDER CAP SCREW)

Page 21

WHITE RODGERS 36E GAS VALVE

REGULATOR ADJUSTMENT SCREW LOCATION

FIGURE 35

REGULATOR

COVER SCREW

ADJUSTING

SCREW

Manifold Pressure Measurement & Adjustment

NOTE - Pressure test adaptor kit (10L34) is available from

Lennox to facilitate manifold pressure measurement.

1 - Connect test gauge to outlet tap on gas valve.

2 - Disconnect pressure sensing hose from gas valve and plug hose by covering opening with tape or equivalent.

Leave barbed fitting on valve open to atmosphere.

See figure 36.

DIFFERENTIAL PRESSURE SWITCH CIRCUITRY

TEE

BURNER

BOX

DIFFERENTIAL

PRESSURE

SWITCH

HOSE

BARB

COMBUSTION

AIR PRESSURE

SENSING HOSE

BURNER

BOX

SENSING

HOSE

GAS

VALVE

SENSING

HOSE

GAS

VALVE

COMBUSTION

AIR INDUCER PRESSURE

SWITCH

SENSING

HOSE

LEFT SIDE OF PRESSURE SWITCH = MORE NEGATIVE

RIGHT SIDE OF PRESSURE SWITCH = LESS NEGATIVE (Closer to Zero)

FIGURE 36

3 - Start unit and allow 5 minutes for unit to reach steady state.

4 - Examine the burner flame. The flame should be stable and should not lift from the burner. Natural gas should burn blue. L.P./propane gas should burn mostly blue with some orange streaks.

5 - After allowing unit to stabilize for 5 minutes, record manifold pressure and compare to values given in table 6.

Page 22

NOTE - Shut unit off and remove manometer as soon as an accurate reading has been obtained. Take care to replace pressure tap plug.

NOTE - During this test procedure, the unit unit will be overfiring:

D

Operate unit only long enough to obtain accurate reading to prevent overheating heat exchanger.

D

Attempts to clock gas valve during this procedure will be inaccurate. Measure gas flow rate only during nor-mal unit operation.

6 - When test is complete remove obstruction from hose and return hose to gas valve barbed fitting.

Gas Flow

To check for proper gas flow to the combustion chamber, deĆ termine the Btu (kW) input from the unit rating plate. Divide this input rating by the Btu (kW) per cubic foot (cubic meter) of available gas. The result is the required number of cubic feet (cubic meter) per hour. Determine the flow of gas through the gas meter for two minutes and multiply by 30 to get the hourly flow of gas.

High Altitude Information

Unit does not need gas pressure adjustment when operating from 0 to 7500 feet (0 to 2248m). See table 6 for correct manĆ ifold pressures for LP/propane and natural gases.

Other Unit Adjustments

Natural to LP/Propane Changeover

A natural gas to LP/propane gas changeover kit is required to convert unit. Refer to installation instructions supplied with kit for conversion procedure.

Heat Anticipation Settings

Thermostat anticipator setting (if adjustable) should be set according to amps listed on wiring diagram on unit.

Flame Rollout Switch

Factory set: No adjustment necessary.

Limit Control

Factory set: No adjustment necessary.

Pressure Switch

Factory set: No adjustment is necessary.

Fan Control

The fan-on delay of 45 seconds is not adjustable. The fanoff delay (time that the blower operates after the heating demand has been satisfied) can be adjusted by moving the jumper on the SureLightt integrated control. The unit is shipped with a factory fan-off delay of 90 seconds. The fanoff delay will affect comfort and is adjustable to satisfy indiĆ vidual applications. See figure 37.

60sec.

FANĆOFF TIME ADJUSTMENT

90sec.

120sec.

180sec.

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

FIGURE 37

Temperature Rise

Check temperature rise and, if necessary, adjust blower speed to maintain temperature rise within range shown on unit rating plate.

Electrical

1 - Check all wiring for loose connections.

2 - Check circuit breaker located on unit control box.

3 - Check for correct voltage at the furnace (furnace operĆ ating).

4 - Check amp-draw on blower motor.

Motor Nameplate __________Actual__________.

NOTE - Do not secure electrical conduit directly to ducting or structure.

Blower Speeds

Refer to blower speed selection chart on unit wiring diagram.

NOTE - CFM readings are taken external to unit with a dry evaporator coil, filter installed and without any other accesĆ sories.

Electronic Ignition

The SureLightt integrated control has an added internal watchguard feature. The feature serves as an automatic reset device for ignition controls locked out because the burner has failed to light. This type of nuisance lockout is usually attributed 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 control to relight the furnace.

Burner Flame

Burner Flame -- Start burner and allow to operate for a few minutes to establish normal burning conditions. Check burner flame by observation. Flame should be predomiĆ nantly blue and strong in appearance.

Check burner flame periodically to ensure proper operation.

Service

WARNING

Disconnect power before servicing unit.

CAUTION

Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Verify proper operation after servicing.

Annual Service

At the beginning of each heating season, system should be checked as follows by a qualified service technician:

Electrical

1 - Check all wiring for loose connections.

2 - Check circuit breaker located on unit control box.

3 - Check for correct voltage at unit (unit operating).

4 - Check amp-draw on blower motor.

Motor Nameplate_________Actual_________

5 - Check to see that heat (if applicable) is operating.

Blower

Check the blower wheels for debris and clean if necessary.

The blower motors are prelubricated for ex-tended bearing life. No further lubrication is needed.

Filters

1 - Filters must be cleaned or replaced when dirty to assure proper furnace operation.

2 - Reusable foam filters used with G26 can be washed with water and mild detergent. When dry, they should be sprayed with filter handicoater prior to reinstallaĆ tion. Filter handicoater is RP Products coating no. 418 and is available as Lennox part no. P-8-5069.

3 - If replacement is necessary, order Lennox part no.

31J81 for 14 inch x 25 inch (356 x 635mm) filter for

G26-50 and -75 units and P-8-7831 for 20 inch x 25 inch (508 x 635mm) filter for G26Q4/5-75, G26-100 and -125 units.

Intake and Exhaust Lines

Check intake and exhaust lines and all connections for tightness and make sure there is no blockage. Also check condensate line for free flow during operation.

Insulation

Outdoor piping insulation should be inspected yearly for deterioration. If necessary, replace with same materials.

Winterizing and Condensate Trap Care

1 - Turn off power to unit.

2 - Have a shallow pan ready to empty condensate water.

Avoid spilling water into the control box.

3 - Remove clamp from flue assembly and remove boot or cap. Empty water from cap. Visually inspect bottom of flue assembly. Replace boot and clamp.

4 - Remove boot from condensate trap and empty water.

Inspect trap then replace boot.

Cleaning DuralokPlus TM Heat Exchanger

If it is necessary to clean the heat exchanger, follow the proĆ cedure below and refer to figure 1 when disassembling the unit. Use papers or protective covering in front of furnace while removing heat exchanger assembly.

1 - Turn off electrical and gas power supplies to furnace.

2 - Remove upper and lower furnace access panels.

3 - Remove four screws around air intake fitting and lift inĆ take pipe up and away.

4 - Loosen hose clamp securing top of flue transition to bottom of flue collar. Remove screw securing flue colĆ lar to top cap and lift exhaust pipe and flue collar up and away.

5 - If electrical field makeĆup box is located inside the unit, it must be removed.

6 - Remove gas supply line connected to gas valve.

Page 23

7 - Mark all gas valve wires and disconnect them from valve. Mark and remove wires from flame rollĆout switch.

8 - Remove top cap of unit.

9 - Remove sensor wire from SureLightt control. DisĆ connect 2Ćpin plug from the ignitor.

10- Mark and disconnect pressure switch tubing from both sides of the pressure switch.

11 - Loosen two screws holding gas manifold support at vestibule panel.

12 - Remove four burner box screws at the vestibule panel and remove burner box and gas valve/manifold asĆ sembly with bracket.

13 - Drain condensate trap. Disconnect condensate line from the outside of unit. Remove condensate line from condensate trap by turning the adapter fitting counterĆ clockwise. The fitting has standard right-hand threads.

14 - Disconnect the drain hose from the flue transition to the elbow on the cold header (collector) box trap.

15 - Disconnect the 2Ćpin plug from the combustion air inĆ ducer at the blower deck. Remove four screws from combustion air inducer and remove flue transition and inducer assembly from cabinet. Take care not to lose the combustion air orifice.

16 - Disconnect 9Ćpin plug from the blower compartment at the blower deck.

17 - Remove 9Ćpin plug above the blower deck.

18 - Remove the limit switch and the pressure switch from the vestibule panel.

19 - Remove two screws from the front cabinet flange at the blower deck. Remove front screws from cabinet at blower deck on left and right sides. Cabinet sides must be slightly spread to clear heat exchanger passage.

20 - Remove screws along vestibule sides and bottom which secure vestibule panel and heat exchanger asĆ sembly to cabinet. Remove heat exchanger.

21- Back wash heat exchanger with soapy water solution or steam. If steam is used it must be below 275°F

(135°C) .

22 - Thoroughly rinse and drain the heat exchanger. Soap solution can be corrosive so take care that entire asĆ sembly is completely rinsed.

23 - Re-install heat exchanger into cabinet making sure that the clamshells of the heat exchanger assembly are resting in the notches of the support located at the rear of the cabinet. This can be viewed by removing the indoor blower and examining through the blower opening.

24 - ReĆsecure the supporting screws along the vestibule sides and bottom to the cabinet.

25 - ReĆinstall cabinet screws on sides and front flange at blower deck.

26 - ReĆinstall the limit switch and pressure switch on the vestibule panel.

27 - ReĆinstall 9Ćpin plug to blower deck and connect it to the 9Ćpin plug from below the blower deck.

28 - ReĆinstall the combustion air inducer. Check the plasĆ tic orifice in the inducer inlet to make sure it has not fallen out. See figure 1. Reconnect the 2Ćpin plug to the wire harness. ReĆinstall the flue transition in the cabinet and reĆattach the drain tube. Route the drain tube below the combustion air inducer housing and to the elbow on the cold header (collector) box trap. See figure 36.

29 - ReĆinstall condensate line with adapter to condensate trap. Use fresh Teflon tape to ensure a leak-free joint.

ReĆconnect to condensate line outside of the unit.

30 - ReĆinstall the burner box. Tighten the screws holding the support bracket. It is important that the glass fiber gasket not be damaged so it will provide a continuous seal between the burner box and the vestibule panel.

31 - With the pressure switch mechanism oriented on the right, reconnect pressure switch tubing by connecting the tubing from the burner box to the barbed fitting on the bottom. Connect the tubing from the combustion air inducer to the barbed fitting on the top. See figure

36.

32 - Reconnect the sensor and ignitor wires.

33 - ReĆinstall top cap to unit.

34 - ReĆinstall electrical connections to gas valve. Orange wire to M1 and yellow wire to C2. Reconnect wires to flame rollĆout switch.

NOTE - Unit is polarityĆsensitive. 120V supply wiring must be installed correctly.

35 - Reconnect main gas line to gas valve.

36 - ReĆinstall field makeĆup box if removed.

37 - ReĆinstall exhaust pipe/flue collar and secure flue colĆ lar to the unit top cap using existing screw. Insert the bottom of the flue collar into the top of the flue transiĆ tion and tighten hose clamp.

38 - ReĆinstall intake pipe fitting to burner box with screws.

39 - Replace both upper and lower access panels.

40 - Refer to instruction on verifying gas and electrical conĆ nections when reĆestablishing supply.

41 - Following lighting instructions from installation manuĆ al, light and run unit for 5 minutes to ensure heat exĆ changer is clean, dry and operating safely.

Cleaning the Burner Assembly

1 - Turn off electrical and gas power supplies to furnace.

Remove upper and lower furnace access panels.

2 - Disconnect the gas supply line to gas valve. DependĆ ing on gas plumbing installation, the gas manifold may move aside enough that breaking the union may not be necessary.

3 - Remove five screws from edges of burner box cover.

G26-50 units have only four screws.

4 - Loosen two screws on bottom of burner box front. The cover is key holed at these screw point so screws do not need to be removed. Pull off cover and set aside.

6 - Mark all gas valve wires and disconnect them from valve.

7 - Mark and disconnect sensor wires from the burner box at the ignition control. Disconnect 2Ćpin plug from the ignitor at the burner box.

Page 24

8 - Loosen two screws at the gas manifold support brackĆ et.

9 - Pull on the left side of the gas manifold and follow with tension to the right side. The manifold support bracket will be free of the mounting screws on the vestibule panel. Set the gas manifold/gas valve assembly aside.

Take care not to damage foam gaskets on each end of the gas manifold.

10 - Using a 1/4 inch nut driver, remove the burner mountĆ ing screws from underneath the burners.

11 - While supporting ignitor and sensor lines at the gromĆ met, grasp burners and simultaneously pull burners and grommet out of the burner box.

12 - Remove ignitor and sensor bracket assemblies from burners using a 1/4 inch nut driver to remove two screws from each bracket.

13 - Clean burner by running a vacuum with a soft brush atĆ tachment over face of burners. Visually inspect inside of burners and crossovers for any blockage caused by forĆ eign matter. Remove any blockage.

14 - ReĆinstall ignitor and sensor bracket assemblies on burners.

NOTE - Ignitor must be installed on the opposite side of the burner from the metal button protrusions. Screws which attached the ignitor bracket must be installed from the same side as the ignitor and through the brackĆ et to engage in the smaller holes located in the burner.

The correct burner orientation is with metal button proĆ trusions always pointing up.

15 - Replace burner ignitor assembly back into burner box so that grommet groove fits back into sheet metal notch and makes a good seal. The burners sit on top of the burner box flanges. Make certain that the screws from the underneath the box pass through the larger holes in the flange and engage in the smaller holes in the burner. ReĆinstall the two screws.

16 - ReĆinstall the gas manifold/gas valve assembly by first inserting the right hand side of the gas manifold into the burner box. Swing left side of manifold into box while engaging support bracket to vestibule panel screws. Check that foam gaskets are providing a seal around each end of the gas manifold. All gas orifices should be engaged. If at this point the burners were mounted in the wrong holes, this needs to be corĆ rected. The saddle brackets on the gas manifold should be flush with the front surfaces on the burner box sides.

17 - Inspect the dual layered metal pieces at the front lip of the cover. These pieces must sandwich around the metal. ReĆinstall burner box cover.

18 - ReĆinstall the screws to secure the burner box cover.

Make sure screws are tight to ensure a leak tight burnĆ er box. Tighten the two screws underneath the box.

Again, inspect the grommet to ensure a tight seal.

19 - Tighten the two screws holding the manifold bracket to the vestibule panel.

20 - ReĆinstall the electrical connections to the gas valve.

Orange wire to M1 and yellow wire to C2.

21 - ReĆinstall the 2Ćpin ignitor plug at the burner box. ReĆ install sensor line to ignition control spade connector.

22 - Reconnect gas line to gas valve.

23 - Replace lower access panel.

24 - Following lighting instructions and gas line connection test procedures from installation manual.

25 - Replace upper access panel.

Page 25

Repair Parts List

The following repair parts are available through Lennox dealers. When ordering parts, include the complete furnace model number listed on the unit rating plate. Example: G26Q3-75.

CABINET PARTS

Cabinet cap

Blower panel

Upper access panel

CONTROL PANEL PARTS

Surelightt integrated control

Transformer

Circuit breaker

Door interlock switch

BLOWER PARTS

Blower wheel

Motor

Motor mounting frame

Motor capacitor

Blower housing cutĆoff plate

Blower housing

HEATING PARTS

Heat exchanger/coil assembly

Gas manifold

Main burner orifices

Main burners

Gas valve

Ignitor

Primary limit control

Flame rollout switch

Filter and filter rack assembly

Flue transition

Pressure switch

Flame sensor

Sight glass and grommet

Rubber boot trap

Foam manifold gaskets

Combustion air inducer

Condensate pipe plug and adapter

Cold end header (collector) box

Troubleshooting

DIAGNOSTIC CODES

LED #1

SIMULTANEOUS

SLOW FLASH

SIMULTANEOUS

FAST FLASH

SLOW FLASH

OFF

LED #2

SIMULTANEOUS

SLOW FLASH

SIMULTANEOUS

FAST FLASH

ON

SLOW FLASH

DESCRIPTION

Power on -- Normal operation.

Also signaled during cooling and continuous fan.

Normal operation - signaled when heating demand initiated at thermostat.

Primary or secondary limit switch open.

Pressure switch open or has opened 5 times during a single call for heat;

OR: Blocked inlet/exhaust vent; OR: Condensate line blocked;

OR: Pressure switch closed prior to activation of combustion air inducer.

ALTERNATING

SLOW FLASH

SLOW FLASH

ON

ON

ON

OFF

FAST FLASH

ALTERNATING

SLOW FLASH

OFF

SLOW FLASH

ON

OFF

ON

SLOW FLASH

Watchguard -- burners failed to ignite.

Flame sensed without gas valve energized.

Rollout switch open. OR: 9Ćpin connector improperly attached.

Circuit board failure or control wired incorrectly.

Main power polarity reversed. Switch line and neutral.

SLOW FLASH

ALTERNATING

FAST FLASH

FAST FLASH

ALTERNATING

FAST FLASH

Low flame signal. Measures below .7 microAmps. Replace flame sense rod.

Improper main ground or line voltage below 75 volts;

OR: Broken ignitor; OR: Open ignitor circuit.

NOTE - Slow flash equals 1 Hz (one flash per second). Fast flash equals 3 Hz (three flashes per second).

Minimum flame sense current = 0.15 microAmps.

Page 26

Troubleshooting

SURELIGHT CONTROL

HEATING SEQUENCE OF OPERATION

NORMAL HEATING MODE

POWER ON

CONTROL SELF-CHECK OKAY?

COMBUSTION AIR INDUCER ON FOR 1 SECOND.

NO

LED#1 AND LED#2

ALTERNATING FAST

FLASH. SIGNAL

HOLDS UNTIL UNIT IS

PROPERLY GROUND.

TURN INDUCER ON FOR 1 SECOND.

IS POLARITY REVERSED?

NO

NO

IS THERE

PROPER GROUND?

YES

YES

IS VOLTAGE

ABOVE 75 VOLTS?

ABNORMAL HEATING MODE

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

INDOOR BLOWER ON.

LED #1 ALTERNATING FAST FLASH

LED#2 ALTERNATING FAST FLASH

CHECK FOR BROKEN IGNITOR OR

OPEN IGNITOR CIRCUIT

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER DELAY OFF.

LED #1 ON

LED #2 ON

(RESET CONTROL BY TURNING MAIN POWER OFF.)

NO

POLARITY REVERSED.

LED #1 -- FAST FLASH

LED #2 -- SLOW FLASH

ROLLOUT SWITCH CLOSED?

YES

YES

NO

LED#1 AND LED#2 ALTERNATING FAST

FLASH. SIGNAL HOLDS UNTIL VOLTAGE

RISES ABOVE 75 VOLTS.

NO

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH DELAY.

LED #1 -- ON. LED #2 -- SLOW FLASH.

SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES.

BURNER OFF?

(CONTINUOUS FLAME CHECK)

YES

NORMAL OPERATION:

LED #1 -- SLOW FLASH

LED #2 -- SLOW FLASH

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

INDOOR BLOWER ON HEATING SPEED.

LED #1 -- SLOW FLASH

LED #2 -- OFF

THERMOSTAT CALLS FOR HEAT:

LED #1 -- FAST FLASH

LED #2 -- FAST FLASH

YES

IS COMBUSTION AIR

PRESSURE SWITCH OPEN?

YES

IS COMBUSTION AIR INDUCER ENERGIZED?

(HTG ACC TERMINAL IS ENERGIZED WITH C.A.B.)

YES

HAS COMBUSTION AIR PRESSURE

SWITCH CLOSED IN 2.5 MINUTES?

YES

15ĆSECOND COMBUSTION AIR INDUCER PREPURGE

INITIATED BY CLOSED PRESSURE SWITCH.

YES

CONTINUED NEXT PAGE

NO

NO

GAS VALVE OFF.

COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH DELAY.

LED #1 OFF

LED #2 SLOW FLASH

(Sequence holds until pressure switch closes or thermostat resets control.)

PRESSURE SWITCH IS IN WATCHGUARD MODE.

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH DELAY.

LED #1 -- OFF. LED #2 -- SLOW FLASH.

IS 5ĆMINUTE RESET PERIOD COMPLETE?

Page 27

Troubleshooting

NORMAL HEATING MODE

15ĆSECOND COMBUSTION AIR INDUCER PREPURGE

INITIATED BY CLOSED PRESSURE SWITCH.

YES

IGNITOR WARMĆUP -- 20 SECONDS.

YES

4ĆSECOND TRIAL FOR IGNITION.

GAS VALVE OPENS. IGNITOR IS ENERGIZED

YES

FLAME STABILIZATION PERIOD.

4 SECONDS

FLAME RECTIFICATION CURRENT

CHECK. CAN FLAME BE PROVEN WITHIN

4 SECONDS AFTER GAS VALVE OPENS?

(u0.15 microamps)

YES

FLAME PRESENT?

YES

FLAME SIGNAL ABOVE 0.7 MICROAMPS?

YES

INDOOR BLOWER ON DELAY BEGINS

(45 seconds.)

YES

PRIMARY AND SECONDARY LIMIT

SWITCHES CLOSED?

YES

ABNORMAL HEATING MODE

NO

YES

IS VOLTAGE ABOVE 75 VOLTS?

YES

IS THERE A PROPER GROUND?

NO

NO

YES

IS IGNITOR INTACT AND CONNECTED?

NO

LEDS SIGNAL

ALTERNATING

FAST FLASH

NO

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

INDOOR BLOWER OFF.

HAS CONTROL FAILED TO SENSE FLAME FOR

FIVE CONSECUTIVE TRIES DURING A SINGLE

HEAT DEMAND?

NO

NO

IGNITION WATCHGUARD MODE. GAS VALVE OFF.

COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH DELAY

LED 1 ALT. SLOW FLASH LED 2 ALT SLOW FLASH

IS 60ĆMINUTE RESET PERIOD COMPLETE?

YES

HAS CONTROL RESET IGNITION

SEQUENCE FOUR TIMES?

YES

NO

NO LOW FLAME SIGNAL

(Does not affect operation of control)

LED #1 -- SLOW FLASH

LED #2 -- FAST FLASH

NO

GAS VALVE DE-ENERGIZED.

COMBUSTION AIR INDUCER

DE-ENERGIZED. INDOOR BLOWER

ON UNTIL SWITCH CLOSES.LED #1

-- SLOW FLASH. LED #2 -- ON.

IS LIMIT SWITCH CLOSED?

YES

HAS PRIMARY/SECONDARY LIMIT

RESET (CLOSED) WITHIN 3

MINUTES?

YES

LIMIT SWITCH WATCHĆ

GUARD MODE. GAS

VALVE OFF. COMB. AIR

INDUCER OFF. INDOOR

BLOWER OFF WITH

DELAY. LED#1-SLOW

FLASH LED#2 - ON. IS

60MINUTE RESET

PERIOD COMPLETE?

NO

YES

ROLLOUT SWITCH CLOSED?

YES

NO GAS VALVE POWER OFF.

COMBUSTION AIR INDUCER POWER OFF.

INDOOR BLOWER OFF WITH DELAY

LED #1 -- ON. LED #2 -- SLOW FLASH.

SEQUENCE HOLDS UNTIL ROLLOUT SWITCH IS RESET

COMBUSTION AIR PRESSURE

SWITCH CLOSED?

YES

THERMOSTAT DEMAND SATISFIED.

YES

LED #1 & #2 SIMULTANEOUS SLOW FLASHES.

YES

COMB. AIR INDUCER CONTINUES 5ĆSECOND

POST PURGE AFTER T'STAT DEMAND IS SATISFIED.

INDOOR AIR BLOWER COMPLETES SELECTED OFF"

DELAY BEFORE SHUTTING OFF.

NO

GAS VALVE DE-ENERGIZED.

COMBUSTION AIR INDUCER ON.

INDOOR BLOWER OFF WITH DELAY

LED #1 -- OFF. LED #2 -- SLOW FLASH.

HAS CAB SWITCH CLOSED IN 2.5 MINUTES?

NO

5ĆMINUTE PRESSURE SWITCH

WATCHGUARD MODE.

YES

YES

Page 28

Troubleshooting

SURELIGHT CONTROL

COOLING SEQUENCE OF OPERATION

NORMAL COOLING MODE ABNORMAL COOLING MODE

POWER ON

IGNITION CONTROL MAIN POWER ON.

LED#1 AND LED#2

ALTERNATING FAST

FLASH. SIGNAL

HOLDS UNTIL UNIT IS

PROPERLY GROUND.

CONTROL SELF DIAGNOSTIC CHECK.

IS CONTROL OPERATING NORMALLY?

YES

TURN INDUCER ON FOR 1 SECOND.

NO

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH NORMAL DELAY.

SIGNAL CIRCUIT BOARD FAILURE AT LED.

INTERRUPT MAIN POWER TO RESET CONTROL.

YES

NO

IS POLARITY REVERSED?

NO

IS THERE

PROPER GROUND?

YES IS VOLTAGE

ABOVE 75 VOLTS?

LED#1 FAST FLASH LED#2 SLOW FLASH

NO

LED#1 AND LED#2 ALTERNATING FAST

FLASH. SIGNAL HOLDS UNTIL VOLTAGE

RISES ABOVE 75 VOLTS.

ROLLOUT SWITCH MONITORED CONTINUOUSLY.

IS ROLLOUT SWITCH CLOSED?

YES

CHECK FOR MAIN BURNER FLAME SENSE.

IS MAIN BURNER FLAME OFF?

NO

NO

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH NORMAL DELAY.

SIGNAL CIRCUIT BOARD FAILURE AT LED.

SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES.

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH NORMAL DELAY.

SIGNAL CIRCUIT BOARD FAILURE AT LED.

SEQUENCE HOLDS UNTIL FLAME IS NOT SENSED.

LED: SLOW FLASH RATE REMAINS UNCHANGED

THROUGHOUT COOLING CYCLE.

THERMOSTAT CALLS FOR COOLING.

COMPRESSOR CONTACTOR AND SYSTEM FAN

ENERGIZED WITH 0ĆSECOND DELAY. ACB

COOL SPEED TERMINAL IS ENERGIZED. ACC.

TERMINAL IS ENERGIZED.

THERMOSTAT OPENS.

COMPRESSOR OFF.

SYSTEM FAN AND ACC. TERM. OFF

WITH 0ĆSECOND DELAY.

Page 29

Troubleshooting

SURELIGHT CONTROL

CONTINUOUS FAN SEQUENCE OF OPERATION

LED: SLOW FLASH RATE REMAINS

UNCHANGED THROUGHOUT SEQUENCE.

MANUAL FAN SELECTION MADE AT THERMOSTAT.

CONTROL (G) ENERGIZES INDOOR BLOWER AT

ACB LOW SPEED. ACC. TERM. IS ENERGIZED.

NO

THERMOSTAT CALLS FOR HEAT (W).

YES

NO

THERMOSTAT CALLS FOR COOLING.

YES

HTG ACC. TERM. ENERGIZES

WITH COMB. AIR INDUCER.

INDOOR BLOWER SWITCHES TO ACB HEAT

SPEED AFTER NORMAL DELAY.

INDOOR BLOWER SWITCHES TO ACB COOL SPEED.

THERMOSTAT OPENS. COMBUSTION AIR INDUCER

AND HTG ACC. TERMINAL ARE DE-ENERGIZED.

THERMOSTAT OPENS.

INDOOR BLOWER SELECTED TIME OFF DELAY BEGINS.

AFTER DELAY ACB HEAT SPEED DE-ENERGIZED.

(blower remains energized during continuous fan mode).

INDOOR BLOWER SWITCHES TO ACB LOW

SPEED. ACC. TERM. REMAINS ENERGIZED.

Page 30

G26 Start-Up & Performance Check List

Job Name

Job Location

Installer

START-UP AND PERFORMANCE CHECK LIST

Job No.

City

City

Technician Unit Model No.

Serial No.

HEATING SECTION

Electrical Connections Tight?

Supply Voltage

Blower Motor Amps

Blower Motor H.P.

Gas Piping Connections

Tight & Leak-Tested?

Fuel Type: Natural Gas? LP/Propane Gas?

Furnace Btu Input

Line Pressure

Regulator Pressure: w.c. Ċ Nat.; w.c. Ċ LP/Propane

Flue Connections Tight?

Fan Control Setting (45 Seconds Fixed On)

Fan Control Off Setting

Filter Clean & Secure?

Temperature Rise

Vent Clear?

THERMOSTAT

Heat Anticipator Properly Set?

Level?

Date

State

State

Page 31