Lennox EL296UH070XE36B, EL296UH135XE60D, EL296UH090XE48C, EL296UH110XE60C, EL296DFE Series Unit Information

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Corp. 1246-L10

Service Literature

Revised 03/2014

EL296UHE SERIES UNITS

EL296UHE series units are high efficiency condensing gas furnaces used for upflow or horizontal applications only, manufactured with Lennox Duralokt heat exchangers formed of aluminized steel. EL296UHE units are available in heating capacities of 44,000 to 132,000 Btuh and cooling applications up to 5 tons. Refer to Product Specifications Manual for proper sizing.

Units are factory equipped for use with natural gas. Kits are available for conversion to LPG operation. EL296UHE model units are equipped with the SureLight integrated control. EL296UHE unit meets the California Ni trogen Oxides (NO Efficiency requirements. All units use a redundant gas valve to assure safety shut-off as required by C.S.A.

All specifications in this manual are subject to change. Pro cedures outlined in this manual are presented as a recom mendation only and do not supersede or replace local or state codes. In the absence of local or state codes, the guidelines and procedures outlined in this manual (except where noted) are recommendations only and do not consti tute code.

Specifications Page 2.............................

I Unit Components Page 7........................

II Installation Page 22.............................

III Start Up Page 44..............................

IV Heating System Service Checks Page 45.........

V Typical Operating Characteristics Page 49.........

VI Maintenance Page 50..........................

VII Wiring and Sequence of Operation Page 53......

VIII Field Wiring and Jumper Settings Page 56.......

X Troubleshooting Page 60........................

) Standards and California Seasonal

TABLE OF CONTENTS

two-stage

EL296UHE

WARNING

Improper installation, adjustment, alteration, service or maintenance can cause property damage, person al injury or loss of life. Installation and service must be performed by a licensed professional HVAC in staller (or equivalent), service agency or the gas sup plier.

WARNING

Sharp edges. Be careful when servicing unit to avoid sharp edges which may result in personal injury.

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SPECIFICATIONS

Gas Heating Performance

High Fire

Temperature rise range - °F 35-65 50-80 45-75

Gas Manifold Pressure (in. w.g.)

Nat. Gas / LPG/Propane

Low Fire

Temperature rise range - °F 20 - 50 25 - 55 30 - 60

Gas Manifold Pressure (in. w.g.)

Nat. Gas / LPG/Propane

High static - in. w.g. Heating 0.5 0.5 0.5

Connections

Intake / Exhaust Pipe (PVC) 2 / 2 2 / 2 2 / 2

in.

Condensate Drain Trap (PVC pipe) - i.d. 3/4 3/4 3/4

with furnished 90° street elbow 3/4 slip x 3/4 Mipt 3/4 slip x 3/4 Mipt 3/4 slip x 3/4 Mipt

with eld supplied (PVC coupling) - o.d. 3/4 slip x 3/4 MPT 3/4 slip x 3/4 MPT 3/4 slip x 3/4 MPT

Indoor

Wheel nominal diameter x width - in. 10 x 8 10 x 8 10 x 10

Blower

Tons of add-on cooling 1.5 - 3 1.5 - 3 2.5 - 4

Air Volume Range - cfm 520 - 1345 550 - 1380 760 - 1740

Electrical Data Voltage 120 volts - 60 hertz - 1 phase

Blower motor full load amps 6.8 6.8 8.4

Maximum overcurrent protection 15 15 15

Shipping Data lbs. - 1 package 129 137 161

NOTE - Filters and provisions for mounting are not furnished and must be eld provided.

Annual Fuel Utilization Efciency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized

furnaces.

Model No. EL296UH045XE36B EL296UH070XE36B EL296UH090XE48C

AFUE 96% 95.5% 95.7%

Input - Btuh 44,000 66,000 88,000

Output - Btuh 43,000 64,000 85,000

3.5 / 10.0 3.5 / 10.0 3.5 / 10.0

Input - Btuh 29,000 43,000 57,000

Output - Btuh 28,000 42,000 55,000

1.7 / 4.9 1.7 / 4.9 1.7 / 4.9

Cooling 0.5 0.5 0.5

Gas pipe size IPS 1/2 1/2 1/2

Motor output - hp 1/2 1/2 3/4

SPECIFICATIONS

Gas Heating Performance

High Fire

Temperature rise range - °F 45-75 55-85

Gas Manifold Pressure (in. w.g.)

Nat. Gas / LPG/Propane

Low Fire

Temperature rise range - °F 35 - 65 40 - 70

Gas Manifold Pressure (in. w.g.)

Nat. Gas / LPG/Propane

High static - in. w.g. Heating 0.5 0.5

Connections

Intake / Exhaust Pipe (PVC) 2 / 2 2 / 2

in.

Condensate Drain Trap (PVC pipe) - i.d. 3/4 3/4

with furnished 90° street elbow 3/4 slip x 3/4 Mipt 3/4 slip x 3/4 Mipt

with eld supplied (PVC coupling) - o.d. 3/4 slip x 3/4 MPT 3/4 slip x 3/4 MPT

Indoor

Wheel nominal diameter x width - in. 11-1/2 x 10 11-1/2 x 10

Blower

Tons of add-on cooling 3 - 5 3.5 - 5

Air Volume Range - cfm 1055 - 2220 1260 - 2405

Electrical Data Voltage 120 volts - 60 hertz - 1 phase

Blower motor full load amps 10.9 10.9

Maximum overcurrent protection 15 15

Shipping Data lbs. - 1 package 174 189

NOTE - Filters and provisions for mounting are not furnished and must be eld provided.

Annual Fuel Utilization Efciency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized

furnaces.

Model No. EL296UH110XE60C EL296UH135XE60D

AFUE 96% 96%

Input - Btuh 110,000 132,000

Output - Btuh 106,000 127,000

3.5 / 10.0 3.5 / 10.0

Input - Btuh 72,000 86,000

Output - Btuh 70,000 84,000

1.7 / 4.9 1.7 / 4.9

Cooling 0.5 0.5

Gas pipe size IPS 1/2 1/2

Motor output - hp 1 1

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OPTIONAL ACCESSORIES - ORDER SEPARATELY

NOTE - FURNACES CANNOT BE TWINNED!

“B” Width

Models

CABINET ACCESSORIES

Horizontal Suspension Kit - Horizontal only 51W10 51W10 51W10

Return Air Base - Upow only 50W98 50W99 51W00

CONDENSATE DRAIN KITS

Condensate Drain Heat Cable 6 ft. 26K68 26K68 26K68

24 ft. 26K69 26K69 26K69

50 ft. 26K70 26K70 26K70

Heat Cable Tape Fiberglass - 1/2 in. x 66 ft. 36G53 36G53 36G53

Aluminum foil - 2 in. x 60 ft. 16P89 16P89 16P89

Crawl Space Vent Drain Kit US 51W18 51W18 51W18

Canada 51W19 51W19 51W19

CONTROLS

Blower Relay Kit (for two-stage outdoor units) 85W66 85W66 85W66

FILTER KITS

Air Filter and

Rack Kit

Horizontal (end) Size of lter - in. 87L96 - 18 x 25 x 1 87L97 - 20 x 25 x 1 87L98 - 25 x 25 x 1

Side Return Single 44J22 44J22 44J22

Ten Pack 66K63 66K63 66K63

Size of lter - in. 16 x 25 x 1 16 x 25 x 1 16 x 25 x 1

SERVICE KITS

Night Service Kit 10B89 10B89 10B89

Universal Service Kit - Switches 89W20 89W20 89W20

TERMINATION KITS

See Installation Instructions for specic venting information.

Termination Kits Direct Vent Applications Only

Termination Kits Direct or NonDirect vent

Roof Termination Flashing Kit - Direct or

Non-Direct Vent (2 ashings)

Cleanable polyurethane, frame-type lter.

Kits contain enough parts for two, non-direct vent installations.

Non-direct vent only.

NOTE - Termination Kits 44W92, 44W93, 30G28, 51W12, 51W19, 81J20 are certied to ULC S636 standard for use in Canada only.

Concentric US - 2 in. 71M80 69M29 - - -

3 in. - - - 60L46 60L46

Canada - 2 in. 44W92 44W92 - - -

3 in. - - - 44W93 44W93

Flush-Mount US - 2, 2-1/2 or 3 in. 51W11 51W11 51W11

Canada - 2, 2-1/2 or 3 in. 51W12 51W12 51W12

Wall - Close

Couple

Wall - Close

Couple WTK

US - 2 in. 22G44 - - - - - -

3 in. 44J40 44J40 44J40

Canada - 2 in. 30G28 - - - - - -

3 in. 81J20 81J20 81J20

Roof 2 in. 15F75 15F75 - - -

Wall Ring Kit 2 in. 15F74

2 in. 44J41 44J41 44J41

“C” Width

“D” Width

Models

15F74 - - -

Models

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BLOWER DATA

EL296UH045XE36B PERFORMANCE (Less Filter)

External

Static

Pressure

in. w.g.

0.00 1345 340 1255 245 1150 185 895 105 845 95

0.10 1305 345 1225 250 1105 200 855 110 810 95

0.20 1290 360 1190 260 1080 205 825 120 780 105

0.30 1275 370 1150 270 1045 215 785 125 720 110

0.40 1220 385 1120 280 1015 220 735 135 690 120

0.50 1215 390 1090 290 980 230 705 140 635 125

0.60 1190 395 1060 300 950 240 650 150 600 135

0.70 N/A N/A 1015 300 900 250 620 155 555 140

0.80 N/A N/A 1000 310 870 260 580 160 520 145

EL296UH070XE36B PERFORMANCE (Less Filter)

External

Static

Pressure

in. w.g.

0.00 1380 315 1305 250 1190 200 965 105 920 100

0.10 1360 325 1270 255 1180 205 915 115 865 100

0.20 1310 335 1250 265 1130 215 880 120 815 110

0.30 1275 340 1205 275 1100 225 835 125 775 115

0.40 1250 355 1175 280 1065 230 795 135 730 125

0.50 1215 370 1145 295 1045 240 745 145 670 130

0.60 1200 380 1100 310 995 245 705 150 640 140

0.70 1145 380 1070 310 960 255 670 160 585 145

0.80 N/A N/A 1035 320 925 265 610 165 550 155

High Medium-High Medium Medium-Low Low

cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts

High Medium-High Medium Medium-Low Low

cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts

Air Volume / Watts at Various Blower Speeds

EL296UH090XE48C PERFORMANCE (Less Filter)

External

Static

Pressure

in. w.g.

0.00 1740 370 1505 250 1370 195 1285 160 1135 125

0.10 1695 390 1470 265 1325 205 1240 170 1090 135

0.20 1660 405 1435 280 1290 220 1195 185 1045 145

0.30 1615 415 1390 295 1240 235 1140 200 995 160

0.40 1590 425 1350 305 1200 245 111 0 210 945 165

0.50 1560 440 1310 320 1155 260 1055 225 895 175

0.60 1525 455 1255 335 1105 270 1005 230 855 190

0.70 1475 470 1220 340 1065 285 960 245 805 200

0.80 N/A N/A 1170 355 1010 295 920 255 760 210

High Medium-High Medium Medium-Low Low

cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts

Air Volume / Watts at Various Blower Speeds

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BLOWER DATA

EL296UH110XE60C PERFORMANCE (Less Filter)

Air Volume / Watts at Different Blower Speeds

External

Static

Pressure

in. w.g.

0.00 2220 645 1940 435 1765 335 1635 280 1435 200 2185 655 1915 440 1745 340 1620 275 1430 195

0.10 2170 660 1920 460 1715 350 1595 290 1380 205 2160 660 1880 460 1705 345 1570 285 1380 205

0.20 2130 680 1865 475 1670 370 1560 305 1345 220 2115 680 1835 470 1670 365 1535 305 1325 220

0.30 2095 700 1835 490 1640 390 1525 325 1285 230 2060 705 1795 495 1630 380 1505 320 1285 230

0.40 2065

0.50 2030 740 1755 525 1560 415 1425 355 1215 260 2000 740 1720 530 1535 415 1410 345 1195 260

0.60 1995 760 1705 550 1525 435 1380 370 1150 270 1955 760 1685 550 1505 435 1380 365 1145 275

0.70 1955 770 1660 560 1475 450 1350 375 1100 290 1935 775 1650 555 1455 450 1325 375 1100 285

0.80 1930 790 1635 575 1445 460 1300 395 1050 305 1890 790 1610 575 1425 460 1285 390 1055 295

EL296UH135XE60D PERFORMANCE (Less Filter)

External

Static

Pressure

in. w.g.

0.00 2405 940 2235 735 2070 545 1830 390 1620 280 2395 925 2235 710 2020 550 1800 380 1610 275

0.10 2365 960 2210 745 2020 565 1770 400 1585 295 2360 935 2175 735 2005 555 1760 395 1550 295

0.20 2330 975 2180 770 1950 580 1745 420 1535 315 2350 955 2160 760 1955 565 1725 415 1510 300

0.30 2295 1000 2120 785 1925 595 1690 435 1480 325 2290 990 2095 775 1890 590 1700 435 1420 325

0.40 2275

0.50 2225 1025 2035 815 1845 630 1605 475 1395 360 2230 1010 2040 815 1845 625 1590 470 1375 360

0.60 2185 1010 2020 835 1815 645 1565 485 1330 365 2170 1025 2000 820 1795 640 1580 485 1335 370

0.70 N/A N/A 1940 850 1735 665 1520 500 1310 385 N/A N/A 1935 845 1725 660 1520 500 1295 385

0.80 N/A N/A 1890 860 1715 680 1465 510 1285 400 N/A N/A 1880 855 1705 680 1470 510 1260 405

Bottom Return Air, Side Return Air with Optional Return Air Base, Return Air from Both Sides or Return Air from Bottom and One Side.

High Med-High Medium Med-Low Low High Med-High Medium Med-Low Low

cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts

720 1785 510 1600 405 1465 335 1250 245 2050 720 1760 510 1570 400 1455 330 1235 245

Air Volume / Watts at Different Blower Speeds

Bottom Return Air, Side Return Air with Optional Return Air Base, Return Air from Both Sides or Return Air from Bottom and One Side.

High Med-High Medium Med-Low Low High Med-High Medium Med-Low Low

cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts

1015 2075 805 1885 615 1640 460 1445 340 2255 995 2060 795 1850 615 1635 445 1390 340

Single Side Return Air − Air volumes in bold require eld

fabricated transition to accommodate 20 x 25 x 1 in. air lter in order to maintain proper air velocity.

Single Side Return Air − Air volumes in bold require eld fabricated transition to accommodate 20 x 25 x 1 in. air lter in order to maintain proper air velocity.

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Gas Valve

EL296UHE PARTS IDENTIFICATION

Field Make Up Box

Burner Box Assembly

Heat Exchanger

Combustion

Air Inducer

Outer Access Panel

Pressure

Switch

Assembly

Door

Interlock

Switch

Inner Access Panel

Bag Assemblies (shipping location)

Primary Limit

Constant Torque Indoor Blower Motor

Two-Stage Integrated Control

FIGURE 1

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I-UNIT COMPONENTS

EL296UHE unit components are shown in figure 1. The

gas valve, combustion air inducer and burners can be ac

cessed by removing the access panel. Electrical compo

nents are in the control box (figure 2) found in the blower

section.

EL296UHE units are factory equipped with a bottom return

air panel in place. The panel is designed to be field re

moved as required for bottom air return. Markings are pro

vided for side return air and may be cut out in the field.

3. Circuit Breaker (CB8)

A 24V circuit breaker is also located in the control box. The switch provides overcurrent protection to the transformer (T1). The breaker is rated 3A at 32V. If the current exceeds this limit the breaker will trip and all unit operation will shut down. The breaker can be manually reset by pressing the button on the face. See figure 3.

CIRCUIT BREAKER CB8

PRESS TO RESET

FIGURE 3

CAUTION

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

A- Control Box

1. Control Transformer (T1)

A transformer located in the control box provides power to

the low voltage section of the unit. Transformers on all

models are rated 40VA with a 120V primary and a 24V sec

ondary.

2. Door Interlock Switch (S51)

A door interlock switch is wired in series with line voltage.

When the inner blower access panel is removed the unit

will shut down.

CONTROL BOX EL296UHE

Transformer

WARNING

Shock hazard. Disconnect power before servicing. Integrated

control is not field repairable. If control is inoper able, simply replace entire control.

Can cause injury or death. Unsafe operation will re sult if repair is attempted.

4. Integrated Control (A92)

Units are equipped with the SureLight grated control. The system consists of a ignition / blower control (figures 4 and 5) with control pin designations in tables 1 and 2 and ignitor (figure 14). The control and ignitor work in combination to ensure furnace ignition and ignitor durability. The control provides gas ignition, safety checks and indoor blower control with two-stage gas heating. The furnace combustion air inducer, gas valve and indoor blow er are controlled in response to various system inputs such as thermostat signal, pressure and limit switch signal and flame signal. The control features a seven-segment LED display, indicating furnace status and error codes. The LED flashes in single digits. For example using table 4 un der LIMIT CODE, an “E” followed by “2” followed by “5” fol lowed by “0”, the limit switch circuit is open. The control also has two unpowered (dry) 1/4” contacts for a humidifier and a 120 volt accessory terminal. Both rated at (1) one amp each.

two-stage, inte

Circuit Breaker

SureLight

FIGURE 2

Interlock Switch

Integrated Control

Electronic Ignition

At the beginning of the heat cycle the integrated control monitors the first stage and second stage combustion air inducer pressure switch. The control will not begin the heating cycle if the first stage pressure switch is closed (bypassed). Likewise the integrated control will not begin the second stage heating cycle if the second stage pressure switch is closed, and will remain in first stage heat. Howev er, if the second stage pressure switch closes during the first stage heat pre-purge, the control will allow second stage heat. Once the first stage pressure switch is deter mined to be open, the combustion air inducer is energized on low (first stage) heat speed. When the differential in the pressure switch is great enough, the pressure switch closes and a 15-second pre-purge begins.

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After the 15-second pre-purge period, the SureLight

igni tor warms up for 20 seconds after which the gas valve opens for a 4-second trial for ignition. The ignitor remains energized during the trial until flame is sensed. If ignition is not proved during the 4-second period, the control will try four more times with an inter purge and warm-up time be tween trials of 35 seconds. After a total of five trials for igni tion (including the initial trial), the control goes into Watch guard-Flame Failure mode. After a 60-minute reset period, the control will begin the ignition sequence again.

NOTE - During abnormal conditions such as low supply voltage or low outdoor temperatures and the low fire pres sure switch does not close, the combustion air inducer will switch to high speed. After the low & high pressure switch close, the unit will proceed with a 15 sec pre-purge, fol lowed by a 20 sec ignitor warm up, then ignition on highfire. After 10 to 20 seconds of high fire operation the unit will switch to low fire.

Two Stage Operation / Thermostat Selection DIP Switch

The control can be utilized in two modes: SINGLE-STAGE thermostat or TWO-STAGE thermostat. The thermostat selection is made using a DIP switch and must be posi tioned for the particular application. DIP switch 1, labeled T”STAT HEAT STAGE is factory-set in the OFF position for use with a two-stage thermostat. Move the DIP switch to ON for use with a single stage thermostat. While in the single-stage thermostat mode, the burners will always fire on first-stage heat. The combustion air inducer will operate on low speed and indoor blower will operate on low heat speed. The unit will switch to second stage heat after a “recognition period”. DIP switch 2, labeled SECOND STAGE DELAY, is factory set in the OFF position for a 7 minute recognition period. The switch can be moved to the ON position for a 12 minute recognition period, after which time the unit will switch to second-stage heat. While in the two-stage thermostat mode, the burners will fire on firststage heat. The combustion air inducer will operate on low speed and indoor blower will operate on low heat speed. The unit will switch to second-stage heat on call from the indoor thermostat. If there is a simultaneous call for first and second stage heat, the unit will fire on first stage heat and switch to second stage heat after 30 seconds of opera tion. See Sequence of Operation flow charts in the back of this manual for more detail.

TABLE 1

SureLight

Control 5 Pin Terminal Designation

PIN # Function

1 Ignitor

2 Combustion Air Inducer High Speed

3 Combustion Air Inducer Low Speed

4 Combustion Air Inducer Neutral

5 Ignitor Neutral

TABLE 2

SureLight

Control 12 Pin Terminal Designation

PIN # Function

1 Gas Valve Second Stage

2 Second Stage pressure Switch

3 Rollout Switch In

4 Ground

5 24V Hot

6 Primary Limit In

7 Gas Valve First Stage

8 Gas Valve Common

9 24V Neutral

10 Ground

11 Primary Limit Out

12 First Stage pressure Switch

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INTEGRATED CONTROL

24VAC Indoor

Blower Terminals

Flame Sense

LED

S4 DIP Switches

Diagnostic Push

Button

HUM

ACC

Ignitor and Combustion

Air Inducer

Neutrals

On Board Links

3/16” QUICK CONNECT TERMINALS

FLAME SENSE SIGNAL

HI COOL 24VAC HI HEAT 24VAC LO COOL 24VAC LO HEAT 24VAC

PAR

COMMON 24VAC

1/4” QUICK CONNECT TERMINALS

NEUTRALS = 120 VAC NEUTRAL

HUM = UNPOWERED NORMALLY OPEN (DRY) CONTACTS

LI = 120 VAC INPUT TO CONTROL

ACC = 120 VAC OUTPUT TO OPTIONAL ACCESSORY

FIGURE 4

THERMOSTAT CONNECTIONS (TB1)

DS = DEHUMIDIFICATION SIGNAL W2 = HEAT DEMAND FROM 2ND STAGE T/STAT W1 = HEAT DEMAND FROM 1ST STAGE T/STAT

R = CLASS 2 VOLTAGE TO THERMO

G = MANUAL FAN FROM

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

Y1 = THERMOSTAT 1ST STAGE COOL SIGNAL

Y2 = THERMOSTAT 2ND STAGE COOL SIGNAL

O = THERMOSTAT SIGNAL TO HEAT PUMP

DH = NOT USED

L = NOT USED

STAT

T'STAT

REVERSING VALVE

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THERMOSTAT SELECTION

TWO STAGE

THERMOSTAT

1−STAGE

THERMOSTAT

(TIMED STAGING)

−SEE SW #2

HEATING BLOWER−OFF DELAY

90 SECOND

HTG BLOWER

OFF DELAY

60 SECOND

HTG BLOWER

OFF DELAY

120 SECOND

HTG BLOWER

OFF DELAY

180 SECOND

HTG BLOWER

OFF DELAY

−BLOWER ON DELAY − 30 SEC. FIXED

INTEGRATED CONTROL CONFIGURATION GUIDE

2ND STAGE HEAT ON DELAY

COOLING BLOWER-OFF

P79

NEUTRALS

DELAY

*45 SECOND COOL BLOWER OFF DELAY

2 SECOND COOL BLOWER OFF DELAY

LOW HEAT SPEED

LOW COOL SPEED

HIGH HEAT SPEED

HIGH COOL SPEED

CONTINUOUS FAN SETTINGS

HSI/CAI

LED

IGN

CAI2

110

4 7

SELECTION

CAI1

CUT FOR

OPTION

W915

2 STAGE

COMPR

W951 HEAT

PUMP W914

DEHUM

ACC

HUM

DIAGNOSTIC

SureLight

7 MIN

UPSTAGE

DELAY

12 MIN

UPSTAGE

DELAY

FLAME SENSE

123456

S4S3

DIAGNOSTIC

PUSH BUTTON

1−STG COMPRESSOR

W915

2 STAGE

COMPR

DO NOT CUT

2−STG COMPRESSOR

W915

2 STAGE

COMPR

CUT LINK

2−STAGE

COMPRESSOR LINK

(JUMPERS Y1 to Y2)

W915

W1W2 G Y2 Y1 C C DHL O DSR

W2GY2

ON−BOARD LINK

OPTION SELECTION

A/C UNIT

W951

HEAT PUMP

DO NOT CUT

HEAT PUMP UNIT

W951

HEAT PUMP

CUT LINK

HEAT PUMP LINK

(JUMPERS R to O)

W951

FIGURE 5

NO SIGNATURESTAT W/ DS CONNECTION

DO NOT CUT

W914

DEHUM

SIGNATURESTAT W/

DS CONNECTION

CUT LINK

W914

DEHUM

DEHUMIFICATION LINK

(JUMPERS R to DS)

W914

−CUT ON−BOARD LINK (SOLDER TRACE) COMPLETELY THROUGH

BOTH LAYERS ON THE CONTROL BOARD

−LINKS CUT IN ERROR −INSTALL A JUMPER ON THE APPROPRIATE TERMINALS ON THE TERMINAL STRIP

−PROTECTIVE PLASTIC FILM ON DIP SWITCHES MAY BE REMOVED FOR EASE IN SETTING OF DIP SW.

* FACTORY DEFAULT

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TABLE 3

Integrated Control Diagnostic Modes

Display Action (when button released)

No change (idle)* Remain in idle mode

Solid “E” Enter diagnostic recall mode

Solid “F” Enter flame signal mode

TABLE 4

Integrated Diagnostic Codes/Status of Equipment

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

Idle mode (Decimal blinks at 1 Hertz -- 0.5 second ON, 0.5 second OFF).

Cooling stage (1 second ON, 0.5 second OFF) 1 or 2 displayed / Pause / Repeat codes.

Dehumidification mode (1 second ON, 1 second OFF) / Pause / Repeat Codes).

Gas Heat Stage (1 second ON, 0.5 second OFF) 1 or 2 displayed / Pause / Repeat codes. Blinking during ignition.

Heat pump stage.

E 110

Low line voltage. Line Voltage Low (Voltage lower than nameplate

rating). Check power line voltage and correct. Alarm clears 5 seconds after fault recovered.

E 111

Line voltage polarity reversed. Reverse line power voltage wiring. System resumes

normal operation 5 seconds after fault recovered.

E 112

Ground not detected System shuts down. Provide proper earth ground.

System resumes normal operation 5 seconds after fault recovered.

E 113

High line voltage. Line Voltage High (Voltage higher than nameplate

rating). Provide power voltage within proper range. System resumes normal operation 5 seconds after fault recovered.

E 114

Line voltage frequency out-of-range. No 60 Hertz Power. Check voltage and line power

frequency. Correct voltage and frequency problems. System resumes normal operation 5 seconds after fault recovered.

E 115

Low 24V - Control will restart if the error recovers. 24-Volt Power Low (Range is 18 to 30 volts). Check

and correct voltage. Check for additional power-rob bing equipment connected to system. May require installation of larger VA transformer to be installed in furnace / air handler. Clears after fault recovered.

E 117

Poor ground detected (Warning only) Provide proper grounding for unit. Check for proper

earth ground to the system. Warning only will clear 30 seconds after fault recovered.

* No change implies the display will continue to show whatever is currently being displayed for normal operation (blinking decimal, active error code, heat state, etc..)

Diagnostic LED (Figure 4)

The seven-segment diagnostic LED displays operating status, error codes and other information. The table begin ning on Page 11 lists diagnostic LED codes.

Diagnostic Push Button (Figure 4)

The diagnostic push button is located adjacent to the seven-segment diagnostic LED. This button is used to en able the Error Code Recall “E” mode and the Flame Signal “F” mode. Press the button and hold it to cycle through a menu of options. Every five seconds a new menu item will be displayed. When the button is released, the displayed item will be selected. Once all items in the menu have been displayed, the menu resumes from the beginning until the button is released.

Error Code Recall Mode

Select ”E” from the menu to access the most recent 10 error codes. Select “c” from the Error Code Recall menu to clear all error codes. Button must be pressed a second time while “c” is flashing to confirm command to delete codes. Press the button until a solid “≡” is displayed to exit the Error Code Recall mode.

Flame Signal Mode

Select ”F” from the menu to access the flame signal mode. The integrated control will display the flame current on seven-segment LED in in micro amps (uA). Flame signal mode is exited after any of the following: D Power is reset

D Pressing and holding push button until 3 horizontal

lines “≡” are displayed

D 10 minutes after entering the flame sense mode.

Page 11

Page 12

E 125

E 200

E 204

E 205

E 206

E 207

E 223

E 224

E 225

E 226

E 227

E 229

E 240

E 241

E 250

TABLE 4 Continued

Control failed self-check, internal error, failed hardware. Will restart if error recovers. Integrated control not communicating. Covers hardware errors (flame sense circuit faults, pin shorts, etc.).

Hard lockout - Rollout circuit open or previously open. Correct cause of rollout trip, or replace flame rollout

Gas valve mis-wired. Check gas valve operation and wiring. Clears when

Gas valve control relay contact shorted. Check wiring on control and gas valve. If wiring is

Gas valve second-stage relay failure Furnace will operate on 1st stage for remainder of

Hot surface ignitor sensed open Measure resistance of hot surface ignitor. Replace

Low pressure switch failed open. Check pressure (inches w.c.) of low pressure switch

Low pressure switch failed closed. Check operation of low pressure switch to see if it is

High pressure switch failed open. Check pressure (inches w.c.) of high pressure

High pressure switch failed closed. Check operation of high pressure switch closing on

Low pressure switch open during trial for ignition or run mode. Check pressure (inches w.c.) of low pressure switch

Ignition on High Fire - Information Only. Code is displayed if 1) low pressure switch fails to

Low flame current - Run mode. Check micro-amperes of flame sensor using control

Flame sensed out of sequence - Flame still present. Shut off gas. Check for gas valve leak. Replace, if

Limit switch circuit open. Check for proper firing rate on furnace. Ensure

Hardware problem on the control. Cycle power on control. Replace if problem prevents service and is persistent. Critical alert. Cleared 300 seconds after fault recovered.

switch. Test furnace operation. Cleared after fault recovered.

repaired.

correct, replace control.

the heating demand. Will clear after fault recovered. If unable to operate 2nd stage, replace control.

if open or not within specified range found in IOM. Resumes normal operation after fault is cleared.

closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air in ducer for correct operation and restriction. Re sumes normal operation after fault is cleared

stuck closed on heat call longer than 150 seconds. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct opera tion and restriction. Resumes normal operation after fault is cleared.

switch closing on heat call. Measure operating pres sure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Re sumes normal operation after fault is cleared.

heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal opera tion after fault is cleared.

closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air in ducer for correct operation and restriction. Re sumes normal operation after fault is cleared.

close, then furnace will switch to high speed inducer to close both low and high pressure switches, then furnace lights on high fire, or 2) if continuous fan is active, furnace lights on high fire for 60 seconds to improve heat exchanger warm up time.

diagnostics or field-installed mode. Clean or replace sensor. Measure voltage of neutral to ground to ensure good unit ground. Alert clears after current heat call has been completed.

necessary. Alert clears when fault is recovered.

there is no blockage in heater. Check for proper air flow. If limit not closed within 3 minutes, unit will go into 1-hour soft lockout. Resumes normal operation after fault is cleared.

Page 12

Page 13

TABLE 4 Continued

E 270

Soft lockout - Exceeded maximum number of retries. No flame current sensed.

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

E 271

Soft lockout - Exceeded maximum number of retries. Last retry failed due to the pressure switch opening.

E 272

Soft lockout - Exceeded maximum number of recycles. Last recycle due to the pressure switch opening.

E 273

Soft lockout - Exceeded maximum number of recycles. Last recycle due to flame failure.

E 274

Soft lockout - Exceeded maximum number of recycles. Last recycle failed due to the limit circuit opening or limit remained open longer than 3 minutes.

E 275

Soft lockout - Flame sensed out of sequence. Flame signal is gone. Shut off gas. Check for gas valve leak. 1-hour soft

E 290

Ignitor circuit fault - Failed ignitor or triggering circuitry. Measure resistance of hot surface ignitor. Replace

Check for proper gas flow. Ensure that ignitor is lighting burner. Check flame sensor current. Clears when heat call finishes successfully.

Check pressure (inches w.c.) of low pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air in ducer for correct operation and restriction. Clears when heat call finishes successfully.

Check operation of low pressure switch to see if it is stuck closed on heat call. Check pressure (inches w.c.) of high pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct opera tion and restriction. Clears when heat call finishes successfully.

Check micro-amperes of flame sensor using control diagnostics or field-installed mode. Clean or replace sensor. Measure voltage of neutral to ground to ensure good unit ground. Clears when heat call finishes successfully.

Shut down system. 1-hour soft lockout. Check firing rate and air flow. Check for blockage. Clears when heat call finishes successfully.

lockout. Clears when flame has been proven stable.

if open or not within specifications. 1-hour soft lock out. Clears when flame has been proven stable.

Page 13

Page 14

Integrated Control DIP Switches

EL296UHE units are equipped with a two-stage integrated control. This control manages ignition timing, heating mode fan off delays and indoor blower speeds based on selections made using the control dip switches and jump ers. 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.

Heating Operation DIP Switch Settings

Switch 1 -- Thermostat Selection -- This unit may be

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

a-a -Select “OFF” for two-stage heating operation con

trolled by a two-stage heating thermostat (factory set ting);

b - Select “ON” for two-stage heating operation con

trolled by a single-stage heating thermostat. This set ting provides a timed delay before second-stage heat is initiated.

Switch 2 a --- Second Stage Delay (Used with SingleStage Thermostat Only) -- This switch is used to deter

mine the second stage on delay when a single-stage ther mostat is being used. The switch is factory-set in the OFF position, which provides a 7-minute delay before secondstage heat is initiated. If the switch is toggled to the ON position, it will provide a 12-minute delay before secondstage heat is initiated. This switch is only activated when the thermostat selector jumper is positioned for SINGLEstage thermostat use.

Indoor Blower Operation DIP Switch Settings

Switches 3 and 4 -- Heating Mode Blower-Off Delay --

The blower-on delay of 30 seconds is not adjustable. The blower-off delay (time that the blower operates after the heating 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 blower-off delay of 90 se conds. The blower off delay affects comfort and is adjust able to satisfy individual applications. Adjust the blower off delay to achieve a supply air temperature between 90° and 110°F at the exact moment that the blower is de-energized. Longer off delay settings provide lower supply air tempera tures; shorter settings provide higher supply air temperatu res.Table 5 provides the blower off timings that will result from different switch settings.

Blower Off Heating Mode Delay Switch Settings

Blower Off Delay

(Seconds)

60 On Off

90 (Factory) Off Off

120 Off On 180 On On

Switch 5 -- Cooling Mode Blower-Off Delay-- The unit is shipped from the factory with the dip switch positioned OFF for a 45 second delay. Table 6 provides the cooling mode off delay settings.

Blower Off Cooling Mode Delay Switch Settings

Blower Off Delay

(Seconds)

45 (Factory) Off

2 On

Switches 6 and 7 -- Continuous Fan Mode -- Continuous fan speed can be controlled by changing DIP switch posi tions. Table 7 below provides DIP switch settings for con tinuous fan mode.

Continuous Fan Mode Settings

Continuous Fan

Mode

Low Heat Speed

(factory)

Low Cool Speed Off On

High High Speed On Off

High Cool Speed On On

TABLE 5

Switch 3 Switch 4

TABLE 6

Switch 5

TABLE 7

Switch 6 Switch 7

Off Off

Onboard Links

W914 Dehum

Onboard link W914, is a clippable connection between ter minals R and DS on the integrated control. W914 must be cut when the furnace is installed with a thermostat which features humidity control. If the link is not cut, terminal “DS' will remain energized not allowing the blower to reduce to low cool speed upon a call for dehumidification.

W951 Heat Pump (R to O)

Onboard link W951 is a clippable connection between ter minals 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 ener gized eliminating the HEAT MODE in the heat pump.

W915 2 Stage Compr (Y1 to Y2)

Onboard link W915 is a clippable connection between ter minals Y1 and Y2 on the integrated control. W915 must be cut if two-stage cooling will be used. If the Y1 to Y2 link is not cut the outdoor unit will operate in second-stage cool ing only.

IMPORTANT

If any onboard link is cut by mistake, install a jump er across the corresponding terminals on the low voltage terminal strip. Do not replace control.

Page 14

Page 15

B- Indoor Blower Motor

BLOWER WHEEL REPLACEMENT

IMPORTANT

Each blower is statically and dynamically bal anced as an assembly before installation in the unit.

EL296UHE units are equipped with a constant torque ECM motor. It has a DC motor coupled to an electronic control module both contained in the same motor housing. The motor is programmed to provide constant torque at each of the five selectable speed taps. Each tap requires 24 volts to energize.

Input Voltage Requirements

The circuit is designed to be operated with AC voltage. To enable a tap requires 12 to 33VAC. Expected current draw will be less than 20mA.

Troubleshooting the Motor

Troubleshooting the motor is an easy process. Follow steps below.

1- Shut off power to unit.

Center Blower Wheel

in Blower Housing

FIGURE 6

ALIGN AND TIGHTEN SET SCREW WITH

FLAT SIDE OF MOTOR SHAFT

2- Remove input plugs P48 and P49 from motor. See fig

ure 8 for troubleshooting procedure. If correct voltage is present in tests 1 and 2 and motor is not operating properly, replace motor. The motor is not field re pairable.

If replacing the indoor blower motor or blower wheel is nec essary, placement is critical. The blower wheel must be centered in the blower housing as shown in figure 6. When replacing the indoor blower motor the set screw must be aligned and tightened with the motor shaft as shown in fig ure 7.

Housing Hub

Motor Shaft

Set Screw

FIGURE 7

Page 15

Page 16

Multi−Meter

)

P49

Test 1

Turn on power to unit. Check for 120 volts across terminals “L” and “N” on input plug P48. If voltage is present continue to test

2. If voltage is not present problem may be may be upstream of plug P48 and proceed to test 3.

P48

(set to VAC)

12012

Multi−Mete

(set to VAC

12012

Test 3 (if necessary)

Check for 120 volts across terminals “L1” and “Neutrals” on the integrated control. If voltage is present, problem is with the har ness. If voltage is not present problem may be may be with the integrated control.

P49

P48

Test 2

Switch thermostat to CONTINUOUS FAN MODE. Check for 24 volts across terminal “C” on input plug P48and speed tap used for continuous fan. (1, 2, 3, 4 or 5) on input plug P49. If 24 volts is not present problem may be up stream of plug P49. Proceed to test

Multi−Meter

(set to VAC)

FIGURE 8

Page 16

Multi−Mete

(set to VAC

Test 4 (if necessary)

Check for 24 volts across terminals “24 COM” and the “active speed tap” on the integrated control. If voltage is present, prob lem is with the harness. If voltage is not present problem may be may be with the integrated control

Page 17

Replacing the Motor Module

1. Disconnect electrical power to unit.

2. Remove unit access panel.

3. Unplug the two harnesses from the motor control mod

ule. See figure 9.

Unplug the Two Harness Connection

Motor Test

TWO HARNESS CONNECTIONS

MOTOR

MOTOR CONTROL MODULE

FIGURE 9

4. Remove the two hex head bolts securing the motor control module to the motor (see figure 10).

Remove the Hex Head Bolts

REMOVE BOTH HEX

HEAD BOLTS

FIGURE 10

5. Slide the motor control module away from the motor to access and disconnect the internal three wire connec tor. It is not necessary to remove blower motor itself. Set both hex head bolts aside.

Testing the Motor (Figure11)

FIGURE 11

TABLE 8

Scale

2 M

200 K

20 K

2 K

200 two hundred ohms 0 - 200

Measurement range in words

two megohm-two million ohms

two hundred kilo-ohm-two hundred thousand ohms

twenty kilo-ohm-twenty thousand ohms

two kilo-ohm two-thousand ohms

ohms

0 - 2,000,000

0 - 200,000

0 - 20,000

0 - 2,000

Motor Module Installation

All replacement motor control modules look similar; how ever, each module is designed for a specific motor size. It is very important to make sure that you are using the correct replacement motor control module. USE OF THE WRONG

MOTOR CONTROL MODULE MAY RESULT IN UNEX PECTED UNIT OPERATION.

1. Verify electrical power to unit is disconnected.

2. Connect three-wire harness from motor to control module.

3. Mount new motor control module to motor using two hex head bolts removed in figure 10. Torque bolts to 22 inch pounds or 1/16

clock

turn as exampled to the right.

4. Reconnect the two harnesses to

1/16

TURN

the motor control module.

5. The electrical connectors of the motor should be facing down to form a drip loop (figure12). This will directs moisture away from the motor and its electric connec tions on the motor.

Drip Loop

If any motor fails the below tests, do not install the new con trol module. The motor is defective and it also must be re placed. The new control can fail if placed on a defective mo tor.

1. Using an ohmmeter check the resistance from any one of the motor connector pins to the aluminum end plate of the motor. This resistance should be greater than 100k ohms.

2. Check the resistances between each of the three mo tor connector pins. These should all read approxim ately the same resistance within an ohm.

3. Check to see if the blower wheel spins freely.

Page 17

BACK OF CONTROL

MODULE

FIGURE 12

CONNECTOR

ORIENTATION

BETWEEN 4 AND 8

O'CLOCK

DRIP LOOP

Page 18

C- Heating Components

1. Ignitor

The SureLight

ignitor is made of durable silicon nitride. The integrated control provides 120 volts to the ignitor for a consistent ignition and long ignitor life. Ohm value should be 39 to 70. See figure 14 for ignitor location and figure 15 for ignitor check out.

NOTE - The EL296UHE furnace contains electronic com ponents that are polarity sensitive. Make sure that the fur nace is wired correctly and is properly grounded.

2. Flame Sensor

A flame sensor is located on the left side of the burner sup port. See figure 14. The sensor tip protrudes into the flame envelope of the left-most burner. The sensor can be re moved for service without removing any part of the burn ers. During operation, flame is sensed by current passed through the flame and sensing electrode. The SureLight control allows the gas valve to remain open as long as flame signal is sensed. To check flame sense signal use the push-button found on the integrated control and go to Field Test Mode. The menu will display the flame signal. See table 9 for flame signal.

TABLE 9

Flame Signal in Microamps

Normal

Low Drop Out

2.6 or greater 2.5 or less 0.6

3. Gas Valve

The valve (figure 14) is internally redundant to assure safe ty shut-off. If the gas valve must be replaced, the same type valve must be used.

24VAC terminals and gas control knob are located on the valve. A wire harness connects the terminals from the gas valve to the electronic ignition control. 24V applied to the terminals energizes the valve.

Inlet and outlet pressure taps are located on the valve. A regulator adjustment screw is located on the valve.

LPG change over kits are available from Lennox. Kits in clude burner orifices and a gas valve.

caused by a blocked heat exchanger, flue or lack of com bustion air. The switch is factory set to trip (open) at 210°F and cannot be adjusted. The switch can be manually reset. To manually reset a tripped switch, push the reset button located on the control.

5. Burners

All units use inshot burners. Burners are factory set and re quire no adjustment. Always operate the unit with the burn er box front panel in place. Each burner uses an orifice that is precisely matched to the burner input. Burners can be re moved as a one piece assembly for service. If burner as sembly has been removed, it is critical to align center of each burner to the center of the clamshell when re-instal ling. See more detail in Section VI- MAINTENANCE.

6. Primary Limit Control (S10)

The primary limit (S10) is located in the heating vestibule panel. When excess heat is sensed in the heat exchanger, the limit will open. If the limit is open, the furnace control en ergizes the supply air blower and closes the gas valve. The limit automatically resets when unit temperature returns to normal. The switch must reset within three minutes or the SureLight control will go into Watch guard for one hour. The switch is factory set and cannot be adjusted. The switch may have a different set point for each unit mod el number. See Lennox Repair Parts Handbook if limit switch must be replaced. When removing switch make note of orientation. When replacing switch make sure the three mounting holes are lined up with the screw holes in the vestibule for correct orientation.

Primary Limit Control (S10)

Mounting Hole

4. Flame Rollout Switches (S47)

Flame rollout switch is a high temperature limit located on top of the burner box, one on each side.- See figure 14. The limit is a N.C. SPST manual‐reset limit. When S47 senses rollout, the circuit breaks and the ignition control immedi ately stops ignition and closes the gas valve. Rollout can be

Mounting Hole

FIGURE 13

Page 18

Page 19

Intake Air Top Cap

Rollout Switch

EL296UHE HEATING COMPONENTS

Burner Assembly

Sensor

Rollout Switch

Ignitor

Burner Box Cover

Manifold And Gas Orifices

Two-Stage Gas Valve

FIGURE 14

Page 19

Page 20

Check ignitor circuit for correct resistance.

Test 1

Remove 5-pin plug from control.

Check ohms reading across terminals 1 and 5.

Reading should be between 39 and 70 ohms. If

value is correct, this is the only test needed.

If the reading on the meter is not correct, (0 or

infinity) then a second test is needed.

Meter

(set to ohms)

EL296UHE Ignitor Check

Integrated Control Detail

Seperate the 2-pin jack-plug near the manifold and check

Check ignitor for correct resistance.

resistance of ignitor at the plug. Reading should be

between 39 and 70 ohms. If the reading is correct, then

the problem is with the wiring between the jack-plug and

the control. If reading is not correct, the issue is the ignitor.

Test 2

Meter

(set to ohms)

Insert meter probes into terminals 1 and 5 (use small

Check ignitor for correct voltage

diameter probes in order not to damage plug).

Check voltage during 20 second ignitor warm up period.

Voltage should read 120 volts +

these values, check for correct supply voltage to furnace.

Test 3

10%. If voltage reads below

Integrated Control Detail

Meter

(set to AC volts)

Integrated Control Detail

FIGURE 15

Page 20

Page 21

7. Combustion Air Inducer (B6) and Cold End Header Box

All EL296UHE units use a two-speed combustion air induc er to move air through the burners and heat exchanger dur ing heating operation. The blower uses a 120VAC motor. The motor operates during all heating operation and is con trolled by integrated control control A92. The inducer also operates for 15 seconds before burner ignition (pre‐purge) and for 5 seconds after the gas valve closes (post‐purge). The inducer operates on low speed during first-stage heat, then switches to high speed for second stage heat.

The combustion air inducer is installed on the cold end header box (CEHB). The cold end header box is a single piece made of hard plastic. The box has an internal chan nel where the combustion air inducer creates negative pressure at unit start up. The channel contains an orifice used to regulate flow created by the combustion air induc er. The box has pressure taps for the combustion air induc er pressure switch hoses. The pressure switch measures the pressure differential across the cold end header box orifice or difference in the channel and the box. If replace

ment is necessary the gaskets used to seal the box to the vestibule panel and the combustion air inducer to the box, must also be replaced.

A pressure switch measures the pressure differential across the CEHB orifice to prove inducer operation. The CEHB orifice will be different for each model. See table 10 for orifice sizes. When the proving switch opens, the fur nace control (A92) immediately closes the gas valve to pre vent burner operation.

TABLE 10

EL296UHE Unit

CEHB Orifice Size

-045 0.618

-070 0.810

-090 0.920

-110 1.040

-135 1.235

8. Combustion Air Inducer Pressure Switch (S18) (Figure 16)

EL296UHE series units are equipped with a dual combus tion air pressure switch (first and second stage) located on the CEHB. The switch is connected to the cold end header box by means of flexible silicone hoses. It monitors nega tive differential pressure across the cold end header box orifice.

The switches are a single‐pole single‐throw pressure switches electrically connected to the integrated control. The purpose of the switches is to prevent burner operation if the combustion air inducer is not operating, the inlet or ex haust pipes or heat exchanger are restricted.

On heat demand (first or second stage) the switch senses that the combustion air inducer is operating. It closes a cir cuit to the integrated control when pressure across the CEHB orifice becomes greater then the switch set point. Set points vary depending on unit size. See table 11. Both pressures sensed by the switches are negative relative to atmospheric pressure. If the inlet or exhaust pipes, or the heat exchanger become obstructed, the switch senses the loss of differential pressure and opens the circuit to the fur nace integrated control and gas valve. A bleed port on the switch allows relatively dry air in the vestibule to purge switch tubing, to prevent condensate build up.

Combustion Air Inducer Pressure Switch

Tap (negative - )

Tap (positive +)

Low Fire Switch

3/16 Terminals

" Terminals

1/4

High Fire Switch

FIGURE 16

NOTE - The switch is factory set and is not field adjustable. It is a safety shut‐down control in the furnace and must not be by-passed for any reason. If switch is closed or bypassed, the control will not initiate ignition at start up.

TABLE 11 0- 4500'

Unit Set Point Low Heat Set Point High Heat

-045 0.40 0.70

-070 0.50 0.90

-090 0.50 0.90

-110 0.50 0.90

-135 0.45 0.90

TABLE 12 4501 - 7500'

Unit Set Point Low Heat Set Point High Heat

-045 0.35 0.55

-070 0.45 0.81

-090 0.50 0.85

-110 0.45 0.81

-135 0.45 0.85

TABLE 13 7501 - 10.000'

Unit Set Point Low Heat Set Point High Heat

-045 0.35 0.50

-070 0.41 0.74

-090 0.45 0.81

-110 0.41 0.74

-135 0.41 0.74

Page 21

Page 22

II-PLACEMENT AND INSTALLATION

All pipe, fittings, primer and solvent cement must conform with American National Standard Institute and the Ameri can Society for Testing and Materials (ANSI/ASTM) stan dards. The solvent shall be free flowing and contain no lumps, undissolved particles or any foreign matter that ad versely affects the joint strength or chemical resistance of the cement. The cement shall show no gelation, stratifica tion, or separation that cannot be removed by stirring. Re fer to the table 14 below for approved piping and fitting ma terials.

CAUTION

Solvent cements for plastic pipe are flammable liq 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 ce ment with skin and eyes.

PIPING AND FITTINGS SPECIFICATIONS

Schedule 40 PVC (Pipe) D1785 Schedule 40 PVC (Cellular Core Pipe) F891

Schedule 40 PVC (Fittings) D2466

Schedule 40 CPVC (Pipe) F441

Schedule 40 CPVC (Fittings) F438

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

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

Schedule 40 ABS Cellular Core DWV (Pipe) F628

Schedule 40 ABS (Pipe) D1527

Schedule 40 ABS (Fittings) D2468

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

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

PRIMER & SOLVENT CEMENT

PVC & CPVC Primer F656 PVC Solvent Cement D2564

CPVC Solvent Cement F493

ABS Solvent Cement D2235

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

ABS to PVC or CPVC Transition Solvent Cement

CANADA PIPE & FITTING & SOLVENT

CEMENT

PVC & CPVC Pipe and Fittings PVC & CPVC Solvent Cement

ABS to PVC or CPVC Transition Cement

POLYPROPYLENE VENTING SYSTEM

PolyPro by Duravent

TABLE 14

D2661

D2665

ASTM

SPECIFICATION

D2564, D2235, F493

D3138

MARKING

ULCS636

ULC-S636

IMPORTANT

EL296UHE exhaust and intake connections are made of PVC. Use PVC primer and solvent cement when using PVC vent pipe. When using ABS vent pipe, use transitional solvent cement to make con nections to the PVC fittings in the unit.

Use PVC primer and solvent cement or ABS solvent ce ment meeting ASTM specifications, refer to Table 14. As an alternate, use all purpose cement, to bond ABS, PVC, or CPVC pipe when using fittings and pipe made of the same materials. Use transition solvent cement when bonding ABS to either PVC or CPVC.

Low temperature solvent cement is recommended during cooler weather. Metal or plastic strapping may be used for vent pipe hangers. Uniformly apply a liberal coat of PVC primer for PVC or use a clean dry cloth for ABS to clean in side socket surface of fitting and male end of pipe to depth of fitting socket.

Canadian Applications Only - Pipe, fittings, primer and solvent cement used to vent (exhaust) this appliance must be certified to ULC S636 and supplied by a single manufacturer as part of an approved vent (exhaust) sys tem. In addition, the first three feet of vent pipe from the fur nace flue collar must be accessible for inspection.

Page 22

Page 23

OUTDOOR TERMINATION USAGE*

TABLE 15

STANDARD CONCENTRIC

Flush

Vent

Input Size

045

070

090

110

135 3 YES

NOTE - Standard Terminations do not include any vent pipe or elbows external to the structure. Any vent pipe or elbows external to the structure must be included in total vent length calculations. See vent length tables. * Kits must be properly installed according to kit instructions.

Requires field-provided outdoor 1-1/2” exhaust accelerator.

Concentric kits 71M80 and 44W92 include 1-1/2” outdoor accelerator, when used with 045 and 070 input models.

Flush mount kits 51W11 and 51W12 include 1-1/2 in. outdoor exhaust accelerator, required when used with 045, 070 and 090 input models.

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

See table 20 for vent accelerator requirements.

Pipe

Dia. in.

2-1/2

2-1/2 YES YES

Mount

Kit

51W11

(US)

51W12

(CA)

2 YES YES YES

3 YES YES

YES YES

YES YES YES

2 inch 3 inch 2 inch

22G44 (US)

30G28 (CA)

Wall Kit Wall Ring Kit

44J40

(US)

81J20 (CA)

YES

15F74

YES

1-1/2 inch 2 inch 3 inch

Field

Fabricated

YES

YES YES YES

YES YES

71M80

(US)

44W92

(CA)

YES

69M29

(US)

44W92

(CA)

60L46 (US)

44W93 (CA)

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

Joint Cementing Procedure

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

use a clean dry cloth for ABS to clean inside socket surface of fitting and male end of pipe to depth of fitting socket.

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

6 - Promptly apply solvent cement to end of pipe and in

DANGER

DANGER OF EXPLOSION!

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

side socket surface of fitting. Cement should be ap plied lightly but uniformly to inside of socket. Take care to keep excess cement out of socket. Apply second coat to end of pipe.

7 - Immediately after applying last coat of cement to pipe,

and while both inside socket surface and end of pipe are wet with cement, forcefully insert end of pipe into

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.

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

socket until it bottoms out. Turn PVC pipe 1/4 turn dur ing assembly (but not after pipe is fully inserted) to dis tribute cement evenly. DO NOT turn ABS or cellular core pipe.

NOTE - Assembly should be completed within 20 sec 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

3 - Clean and dry surfaces to be joined.

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

pipe.

around its entire perimeter. Any gaps may indicate an improper assembly due to insufficient solvent.

9 - Handle joints carefully until completely set.

Page 23

Page 24

Venting Practices

Piping Suspension Guidelines

Conduct the following test while each appliance is operat ing and the other appliances (which are not operating) re main connected to the common venting system. If the vent ing system has been installed improperly, you must cor rect the system as indicated in the general venting re quirements section.

SCHEDULE 40

PVC - 5'

all other pipe* - 3'

* See table 14 for allowable pipe.

NOTE - Isolate piping at the point where it exits the outside wall or roof in order to prevent transmission of vibration to the structure.

NOTE - All horizontal runs of exhaust pipe must slope back to ward unit a minimum of 1/4” (6mm) drop for each 12” (305mm).

Wall Thickness Guidelines

24” maximum 3/4” minimum

inside outside

Wall

insulation

(if required)

FIGURE 17

9. 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.

10. 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 conden sate collection trap and lines.

Removal of the Furnace from Common Vent

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

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 mon oxide poisoning or death. The following steps shall be followed for each ap pliance 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 horizon

tal pitch. Determine that there is no blockage, restric tion, 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 dry 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 oper ate at maximum speed. Do not operate a summer ex haust 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.

6 - After determining that each appliance connected to the

common venting system is venting properly, (step 3) return all doors, widows, exhaust fans, fireplace damp ers, and any other gas-burning appliances to their pre vious mode of operation.

Page 24

Page 25

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

ing tests, the common venting system must be modi fied 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 stan dards of the National Fuel Gas Code ANSI Z223.1.

CHIMNEY

OR GAS

VENT

(Check sizing

for water

heater only)

FURNACE

(Replaced by EL296)

REPLACING FURNACE THAT

WAS PART OF A COMMON

VENT SYSTEM

WATER

HEATER

OPENINGS

(To Adjacent

Room)

If an EL296UHE furnace replaces a furnace which was commonly vented with another gas appliance, the size of the existing vent pipe for that gas ap pliance must be checked. Without the heat of the original furnace flue products, the existing vent pipe is probably oversized for the single water heater or other appliance. The vent should be checked for proper draw with the remaining appliance.

FIGURE 18

Exhaust Piping (Figures 19, 21 and 22)

Route piping to outside of structure. Continue with installa tion following instructions given in piping termination sec tion.

When using the PolyPro

by DuraVent venting system the vent pipe requirements stated in the unit installation in struction – minimum & maximum vent lengths, termination clearances, etc. – apply and must be followed. Follow the instructions provided with PoyPro by DuraVent venting system for assembly or if requirements are more restrict ive. The PolyPro by Duravent venting system must also fol low the uninsulated and unconditioned space criteria listed in table 19.

The EL296UHE can be installed as either a Non-Direct Vent or a Direct Vent gas central furnace.

NOTE - In Non‐Direct Vent installations, combustion air is taken from indoors or ventilated attic or crawlspace and flue gases are discharged outdoors. In Direct Vent installa tions, combustion air is taken from outdoors and flue gases are discharged outdoors.

Intake and exhaust pipe sizing -- Size pipe according to

tables 16 and 17. Count all elbows inside and outside the home. Table 16 lists the minimum vent pipe lengths per mitted. Table 17 lists the maximum pipe lengths permitted.

Regardless of the diameter of pipe used, the standard roof and wall terminations described in section Exhaust Piping Terminations should be used. Exhaust vent termination pipe is sized to optimize the velocity of the exhaust gas as it exits the termination. Refer to table 20.

In some applications which permit the use of several differ ent sizes of vent pipe, a combination vent pipe may be used. Contact Lennox' Application Department for assis tance in sizing vent pipe in these applications.

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

CAUTION

Do not discharge exhaust into an existing stack or stack that also serves another gas appliance. If verti cal discharge through an existing unused stack is re 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 pres sure and must be completely sealed to prevent leak age of combustion products into the living space.

Vent Piping Guidelines

NOTE - Lennox has approved the use of DuraVent® manu factured vent pipe and terminations as an option to PVC.

Page 25

Horizontal Installation Offset Requirements

Exhaust Pipe

Horizontal

12” Max.

Gas Furnace

NOTE - All horizontal runs of exhaust pipe must slope back to ward unit. A minimum of 1/4” (6mm) drop for each 12” (305mm) of horizontal run is mandatory for drainage.

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

NOTE - Exhaust piping should be checked carefully to make

sure there are no sags or low spots.

12” Min.

FIGURE 19

Page 26

MINIMUM VENT PIPE LENGTHS

TABLE 16

EL296UHE

MODEL

045, 070, 090, 110, 135

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

MIN. VENT LENGTH*

15 ft. or

5 ft. plus 2 elbows or

10 ft. plus 1 elbow

Use the following steps to correctly size vent pipe diameter.

Piping Size Process

What is the

furnace capacity?

045, 070, 090,

110 or 135?

Which style termination

being used?

Standard or concentric?

See table 15.

Which needs

most elbows?

Intake or exhaust?

How many elbows? Count all elbows inside

and outside house.

Desired pipe size?

2”, 2-1/2”, 3”

What is the altitude of the furnace installation?

Use table 17 or 18 to find max intake or exhaust pipe

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

FIGURE 20

IMPORTANT

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

Page 26

Page 27

Maximum Allowable Intake or Exhaust Vent Length in Feet

TABLE 17

NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake and Exhaust must be same pipe size. NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation.

Standard Termination at Elevation 0 - 4500 ft

Number Of 90° Elbows

Used

1 81 66 44 24

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

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

4 66 51 29

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

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

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

8 46 31

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

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

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

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

115 115 93 58

100 100 78 43 123 122 103 103 99

n/a

80 80 58 23 103 102 83 83 79

n/a

138 137 118 118 114

n/a

Standard Termination Elevation 4500 - 10,000 ft

Number Of 90° Elbows

Used

1 81 66 44

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

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

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

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

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

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

8 46 31

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

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

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

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

115 115 93 58

n/a n/a

80 80 58 23 103 102 83 83 79

n/a

138 137 118 118 114

n/a

See concentric terminations next page.

Page 27

Page 28

Maximum Allowable Intake or Exhaust Vent Length in Feet

TABLE 17 Continued

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

Concentric Termination at Elevation 0 - 4500 ft

Number Of 90° Elbows

Used

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

1 73 58 42 22

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

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

4 58 43 27

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

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

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

8 38 23

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

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

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

n/a

105 105 89 54

90 90 74 39 106 106 99 99 90

n/a

70 70 54 19 86 86 79 79 70

121 121 114 114 105

Concentric Termination Elevation 4501 - 10,000 ft

Number Of 90° Elbows

Used

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

1 73 58 42

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

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

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

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

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

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

8 38 23

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

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

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

n/a

n/a n/a

105 105 89 54

n/a

70 70 54 19 86 86 79 79 70

121 121 114 114 105

Page 28

Page 29

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

TABLE 18

Attic or Crawl Space For Intake Air in Feet

Standard Termination at Elevation 0 - 4500 ft

Number Of 90° Elbows

Used

1 71 56 34 14

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

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

4 56 41 19

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

6 46 31 9 85 75 63 18 93 92 73 73 69

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

8 36 21

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

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

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

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

100 100 78 43

85 85 63 28 103 102 83 83 79

n/a

65 65 43 8 83 82 63 63 59

n/a

118 117 98 98 94

n/a

Standard Termination Elevation 4500 - 10,000 ft

Number Of 90° Elbows

Used

1 71 56 34

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

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

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

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

6 46 31 9 85 85 53 18 93 92 73 73 69

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

8 36 21

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

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

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

2” Pipe 2-1/2” Pipe 3” Pipe

Model Model Model

100 100 78 43

n/a n/a

65 65 43 8 83 82 63 63 59

n/a

118 117 98 98 94

n/a

Page 29

Page 30

TYPICAL EXHAUST AND INTAKE PIPE CONNECTIONS IN UPFLOW DIRECT OR

NON-DIRECT VENT APPLICATIONS

EXHAUST

2”

INTAKE

2”

EXHAUST INTAKE

3”

TRANSITION

*2”

2”

3”

TRANSITION

*2”

2”

DO NOT transition

from smaller to larger

pipe in horizontal runs

of exhaust pipe.

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

FIGURE 21

2”

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

APPLICATIONS

12” max.

EXHAUST

2”

INTAKE

EXHAUST

*2”

(RIGHT HAND DISCHARGE SHOWN)

2”

3”

*2”

2”

TRANSITION

*2”

2”

3”

*2”

45°

MAX

2”

*2”

2”

SIDE VIEW

45°

MAX

DO NOT transition

from smaller to larger

pipe in horizontal runs

of exhaust pipe.

INTAKE

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

FIGURE 22

Page 30

Page 31

Intake Piping

The EL296UHE furnace may be installed in either direct vent or non-direct vent applications. In non-direct vent

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

Follow the next two steps when installing the unit in Direct Vent applications, where combustion air is taken from outdoors and flue gases are discharged outdoors. The

provided air intake screen must not be used in direct vent applications (outdoors).

1 - Use transition solvent cement or a sheet metal screw

to secure the intake pipe to the inlet air connector.

2 - Route piping to outside of structure. Continue with

installation following instructions given in general guidelines for piping terminations and intake and ex haust piping terminations for direct vent sections. Re fer to table 17 for pipe sizes.

TYPICAL AIR INTAKE PIPE CONNECTIONS

HORIZONTAL NON−DIRECT VENT APPLICATIONS

(Horizontal Right−Hand Air Discharge Application Shown)

PVC pipe

coupling

INTAKE

DEBRIS

SCREEN

(Provided)

NOTE - Debris screen may be positioned straight out (preferred) or with an elbow rotated to face down.

TYPICAL AIR INTAKE PIPE CONNECTIONS

UPFLOW NON−DIRECT

VENT APPLICATIONS

INTAKE

DEBRIS

SCREEN

(Provided)

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

FIGURE 23

FIGURE 24

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

from indoors or ventilated attic or crawlspace and flue gases are discharged outdoors.

1 - Use field-provided materials and the factory-provided

air intake screen to route the intake piping as shown in figure 23 or 24. Maintain a minimum clearance of 3” (76mm) around the air intake opening. The air intake opening (with the protective screen) should always be directed forward or to either side in the upflow position, and either straight out or downward in the horizontal position.

The air intake piping must not terminate too close to the flooring or a platform. Ensure that the intake air inlet will not be obstructed by loose insulation or other items that may clog the debris screen.

2 - If intake air is drawn from a ventilated attic (figure 25)

or ventilated crawlspace (figure 26) the exhaust vent length must not exceed those listed in table 18. If 3” di ameter pipe is used, reduce to 2” diameter pipe at the termination point to accommodate the debris screen.

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

the connector, if desired.

Page 31

Page 32

CAUTION

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

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

Roof T erminated

Exhaust Pipe

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

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

Roof T erminated

Exhaust Pipe

EQUIPMENT IN CONFINED SPACE

Ventilation Louvers

Inlet Air

(Minimum

12 in.(305mm) Abov

attic floor)

*Intake Debris

Screen

(Provided)

Furnace

* See table 18 for maximum vent lengths

per 1.17kW) per

FIGURE 25

EQUIPMENT IN CONFINED SPACE

General Guidelines for Vent Terminations

In Non‐Direct Vent applications, combustion air is taken from indoors or ventilated attic or crawlspace and the flue gases are discharged to the outdoors. The EL296UHE is then classified as a non‐direct vent, Category IV gas fur nace.

In Direct Vent applications, combustion air is taken from outdoors and the flue gases are discharged to the out doors. The EL296UHE is then classified as a direct vent, Category IV gas furnace.

In both Non‐Direct Vent and Direct Vent applications, the vent termination is limited by local building codes. In the ab sence of local codes, refer to the current National Fuel Gas Code ANSI Z223-1/NFPA 54 in U.S.A., and current CSAB149 Natural Gas and Propane Installation Codes in Can ada for details.

Position termination according to location given in figure 28 or 29. In addition, position termination so it is free from any obstructions and 12” above the average snow accumula tion.

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

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

Inlet Air

(Minimum

Ventilation

Louvers

(Crawl space)

Coupling or 3 in. to 2 in.

Transition

(Field Provided)

Furnace

12 in.(305mm)

Above crawl space floor)

*Intake Debris Screen Provided)

* See table 18 for maximum vent lengths

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

FIGURE 26

per 1.17kW) per

IMPORTANT

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

IMPORTANT

For Canadian Installations Only: In accordance to CSA International B149 installation codes, the minimum allowed distance between the combustion air intake inlet and the exhaust outlet of other appliances shall not be less than 12 inches (305mm).

Page 32

Page 33

Maximum Allowable Exhaust Vent Pipe Length (in ft.) Without Insulation

TABLE 19

In Unconditioned Space For Winter Design Temperatures

Winter Design

Temperatures

32 to 21

(0 to -6)

°F (°C)

Vent Pipe

Diameter

045 070 090 110 135

PVC

PP PVC2PP PVC

2 in. 20 18 30 28 40 36 24 24 N/A N/A

2-1/2 in. 15 N/A 22 N/A 30 N/A 40 N/A N/A N/A

Unit Input Size

PP PVC2PP PVC

3 in. 12 10 18 15 25 21 32 28 42 37

2 in 12 11 20 18 25 22 24 24 N/A N/A

20 to 1

(-7 to -17)

2-1/2 in. 10 N/A 14 N/A 20 N/A 24 N/A N/A N/A

3 in. 6 5 10 8 15 12 20 17 22 18

2 in. 8 7 12 11 18 16 22 20 N/A N/A

0 to -20

(-18 to -29)

2-1/2 in. 6 N/A 8 N/A 12 N/A 16 N/A N/A N/A

3 in. 2 1 6 5 10 10 12 11 15 12

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

Poly-Propylene vent pipe (PP)

NOTE - Maximum uninsulated vent lengths listed may include the termination(vent pipe exterior to the structure) and cannot exceed 5 linear feet or the maximum allowable intake or exhaust vent length listed in table 17 or 18 which ever is less.

NOTE - If insulation is required in an unconditioned space, it must be located on the pipe closest to the furnace. See figure27.

Conditioned

Space

Conditioned

Space

FIGURE 27

Pipe Insulation

Unconditioned

Space

Exhaust

Pipe

Intake

Pipe

Page 33

Page 34

VENT TERMINATION CLEARANCES

FOR NON-DIRECT VENT INSTALLATIONS IN THE US AND CANADA

INSIDE CORNER

DETAIL

Fixed

Closed

Operable

VENT TERMINAL

AIR SUPPLY INLET

US Installations

A =

Clearance above grade, veranda,

porch, deck or balcony

B =

Clearance to window or

door that may be opened

C =

Clearance to permanently

closed window

Vertical clearance to ventilated soffit

D =

located above the terminal within a

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

above average snow accumulation.

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

1 foot (30cm) above opening

* 12”

* Equal to or greater than soffit depth.

horizontal distance of 2 feet (610 mm)

from the center line of the terminal

E =

F =

G =

H =

Clearance to unventilated soffit

Clearance to outside corner

Clearance to inside corner

Clearance to each side of center line ex tended above meter / regulator assembly

I =

Clearance to service regulator

vent outlet

J =

Clearance to non-mechanical air

supply inlet to building or the com

bustion air inlet to any other ap

* Equal to or greater than soffit depth.

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

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

above the meter / regulator assembly

* 3 feet (.9m)

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

1 foot (30 cm) above opening

pliance

K =

L =

Clearance to mechanical air sup

ply inlet

Clearance above paved sidewalk or

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

(3m) horizontally

7 feet (2.1m)†

paved driveway located on public property

Clearance under veranda, porch, deck or balcony

M =

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

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

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

*12 inches (305mm)‡

FIGURE 28

Fixed

Closed

AREA WHERE TERMINAL IS NOT PERMITTED

Canadian Installations

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

above average snow accumulation.

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

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

appliances > 10,000 Btuh (3kw) and

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

for appliances > 100,000 Btuh (30kw)

* 12”

* Equal to or greater than soffit depth.

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

above the meter / regulator assembly

3 feet (.9m)

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

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

appliances > 10,000 Btuh (3kw) and

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

for appliances > 100,000 Btuh (30kw)

6 feet (1.8m)

7 feet (2.1m)†

12 inches (305mm)‡

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

Page 34

Page 35

VENT TERMINATION CLEARANCES

FOR DIRECT VENT INSTALLATIONS IN THE US AND CANADA

INSIDE CORNER

DETAIL

Fixed

Closed

Operable

VENT TERMINAL

AIR SUPPLY INLET

US Installations

A =

B =

Clearance above grade, veranda,

porch, deck or balcony

Clearance to window or

door that may be opened

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

above average snow accumulation.

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

Btuh (3kw), 9 inches (228mm) for ap

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

Btuh (15 kw), 12 inches (305mm) for ap

pliances > 50,000 Btuh (15kw)

C =

Clearance to permanently

closed window

Vertical clearance to ventilated soffit

D =

located above the terminal within a

* Equal to or greater than soffit depth

horizontal distance of 2 feet (610mm)

from the center line of the terminal

E =

F =

G =

H =

Clearance to unventilated soffit

Clearance to outside corner

Clearance to inside corner

Clearance to each side of center line ex

tended above meter / regulator assembly

I =

Clearance to service regulator

vent outlet

J =

Clearance to non-mechanical air

supply inlet to building or the com

bustion air inlet to any other ap

pliance

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

* No minimum to outside corner

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

above the meter / regulator assembly

3 feet (.9m)

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

Btuh (3kw), 9 inches (228mm) for ap

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

Btuh (15 kw), 12 inches (305mm) for ap

pliances > 50,000 Btuh (15kw)

K =

Clearance to mechanical air sup

ply inlet

L =

Clearance above paved sidewalk or

paved driveway located on public property

Clearance under veranda, porch, deck or balcony

M =

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

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

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

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

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

(3m) horizontally

* 7 feet (2.1m)

*12 inches (305mm)‡

FIGURE 29

* 12”

Fixed

Closed

AREA WHERE TERMINAL IS NOT PERMITTED

Canadian Installations

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

above average snow accumulation.

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

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

appliances > 10,000 Btuh (3kw) and

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

for appliances > 100,000 Btuh (30kw)

* 12”

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

* No minimum to outside corner

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

above the meter / regulator assembly

3 feet (.9m)

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

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

appliances > 10,000 Btuh (3kw) and

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

for appliances > 100,000 Btuh (30kw)

6 feet (1.8m)

7 feet (2.1m)†

12 inches (305mm)‡

Page 35

Page 36

Details of Intake and Exhaust Piping Terminations for Direct Vent Installations

NOTE - In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged to outdoors.

NOTE - Flue gas may be slightly acidic and may adversely affect some building materials. If any vent termination is used and the flue gasses may impinge on the building ma terial, a corrosion-resistant shield (minimum 24 inches square) should be used to protect the wall surface. If the optional tee is used, the protective shield is recommended. The shield should be constructed using wood, plastic, sheet metal or other suitable material. All seams, joints, cracks, etc. in the affected area should be sealed using an appropriate sealant. See figure 38.

Intake and exhaust pipes may be routed either horizontally through an outside wall or vertically through the roof. In at tic or closet installations, vertical termination through the roof is preferred. Figures 30 through 37 show typical terminations.

1. Intake and exhaust terminations are not required to be in the same pressure zone. You may exit the intake on one side of the structure and the exhaust on another side (figure 31). You may exit the exhaust out the roof and the intake out the side of the structure (figure 32).

2. Intake and exhaust pipes should be placed as close together as possible at termination end (refer to il lustrations). Maximum separation is 3” (76MM) on roof terminations and 6” (152MM) on side wall termina tions.

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

3. On roof terminations, the intake piping should termi nate straight down using two 90° elbows (See figure

30).

4. Exhaust piping must terminate straight out or up as shown. A reducer may be required on the exhaust pip ing at the point where it exits the structure to improve the velocity of exhaust away from the intake piping. See table 20.

Inches(MM)

8” (203MM) MIN

12” (305MM) ABOVE

AVERAGE SNOW

ACCUMULATION

3” (76MM) OR

2” (51MM) PVC

PROVIDE SUPPORT

FOR INTAKE AND

EXHAUST LINES

DIRECT VENT ROOF TERMINATION KIT

3”(76MM) MAX.

(15F75 or 44J41)

SIZE TERMINATION

PIPE PER TABLE 20.

UNCONDITIONED

ATTIC SPACE

1/2” (13MM) FOAM

INSULATION IN

UNCONDITIONED

SPACE

FIGURE 30

Exiting Exhaust and Intake Vent

(different pressure zones)

Exhaust

Pipe

Furnace

Inlet Air (Minimum 12 in. 305 MM) above

grade or snow

accumulation

FIGURE 31

Exiting Exhaust and Intake Vent

(different pressure zones)

Roof T

erminated

Exhaust Pipe

Inlet Air

Furnace

(Minimum 12 in. 305 MM) above

grade or snow

accumulation

FIGURE 32

TABLE 20

EXHAUST PIPE TERMINATION SIZE REDUCTION

EL296UHE

MODEL

*045 and 070

*090 2” (51MM)

110 2” (51MM) 135 2” (51MM)

Termination

Pipe Size

1-1/2” (38MM)

*EL296UHE-045, -070 and -090 units with the flush mount termination must use the 1-1/2”accelerator supplied with the kit.

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

5. On field-supplied terminations for side wall exit, ex haust piping may extend a maximum of 12 inches (305MM) for 2” PVC and 20 inches (508MM) for 3” (76MM) PVC beyond the outside wall. Intake piping should be as short as possible. See figure 38.

6. On field-supplied terminations, a minimum distance between the end of the exhaust pipe and the end of the intake pipe without a termination elbow is 8” and a minimum distance of 6” with a termination elbow. See figure 38.

Page 36

Page 37

7. If intake and exhaust piping must be run up a side wall to position above snow accumulation or other ob structions, piping must be supported. At least one bracket must be used within 6” from the top of the el bow and then every 24” (610mm) as shown in figure 38, to prevent any movement in any direction. When exhaust and intake piping must be run up an outside wall, the exhaust piping must be terminated with pipe sized per table 20.The intake piping may be equipped with a 90° elbow turndown. Using turndown will add 5 feet (1.5m) to the equivalent length of the pipe.

8. A multiple furnace installation may use a group of up to

four terminations assembled together horizontally, as

shown in figure 36.

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

FURNACE

4''

EXHAUST

PIPE

FURNACE

INTAKE

PIPE

GLUE EXHAUST

END FLUSH INTO

TERMINATION

FLAT SIDE

1-1/2” ACCELERATOR

(all -45, -070 and -090 units)

FLUSH-MOUNT SIDE WALL TERMINATION

51W11 (US) or 51W12 (Canada)

FIGURE 33

FIELD-PROVIDED

REDUCER MAY BE REQUIRED

TO ADAPT LARGER VENT

PIPE SIZE TO TERMINATION

OUTSIDE

WALL

EXHAUST

VENT

INTAKE

AIR

CLAMP

(Not Furnished)

1-1/2” (38mm) accelerator

provided on 71M80 & 44W92

kits for EL296UH045XE36B &

INTAKE

AIR

070XE36B

EXHAUST

VENT

AIR

12” (305mm) Min.

above grade or

average snow accumulation.

INTAKE

GRADE

DIRECT VENT CONCENTRIC WALL TERMINATION

71M80, 69M29 or 60L46 (US)

44W92 or 44W93 (Canada)

FIGURE 35

EXHAUST

VENT

INTAKE

AIR

Inches (MM)

optional intake elbow

5”

(127MM)

18” MAX.

(457MM)

EXHAUST VENT

INTAKE

AIR

12”

(305MM)

5-1/2”

(140mm)

Front View

12” (305MM) Min.

above grade or

average snow

accumulation.

Side View

OPTIONAL VENT TERMINATION FOR MULTIPLE UNIT

INSTALLATION OF DIRECT VENT WALL TERMINATION KIT

(30G28 or 81J20)

FIGURE 36

1 1/2” (38mm) accelerator

EXHAUST

12” (305mm)

Minimum

Above Average

Snow

Accumulation

VENT

provided on 71M80 & 44W92

kits for EL296UH045XE36B,

INTAKE

AIR

SHEET METAL STRAP

(Clamp and sheet metal strap must be field installed to support the weight of the termination kit.)

CLAMP

REDUCER MAY BE REQUIRED

TO ADAPT LARGER VENT

PIPE SIZE TO TERMINATION

DIRECT VENT CONCENTRIC ROOFTOP TERMINATION

71M80, 69M29 or 60L46 (US)

44W92 or 44W93 (Canada)

FIGURE 34

070XE36B

FLASHING

(Not Furnished)

FIELD-PROVIDED

Page 37

EL296UHE DIRECT VENT APPLICATION

USING EXISTING CHIMNEY

STRAIGHT-CUT OR

3”-8”

(76MM-203MM)

8” - 12”

(203MM - 305MM)

20.

INTAKE PIPE

INSULATION (optional)

SHEET

METAL TOP

PLATE

INSULATE TO FORM

SEAL

Minimum 12” (305MM)

above chimney top

plate or average snow

accumulation

*SIZE TERMINATION

PIPE PER TABLE

NOTE - Do not discharge exhaust gases directly into any chimney or vent stack. If ver tical 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 illus trated. In any exterior portion of chimney, the exhaust vent must be insulated.

ANGLE-CUT IN DIRECTION

OF ROOF SLOPE *

EXHAUST VENT

1/2” (13MM)

WEATHERPROOF

INSULATION

SHOULDER OF FITTINGS

PROVIDE SUPPORT

OF PIPE ON TOP PLATE

3” - 8”

(76MM-

203MM)

ALTERNATE

INTAKE PIPE

EXTERIOR

PORTION OF

CHIMNEY

FIGURE 37

Page 38

NOTE − FIELD−PROVIDED

REQUIRED TO ADAPT

LARGER VENT PIPE SIZE

* WALL

SUPPORT

REDUCER MAY BE

TO TERMINATION

STRAIGHT

APPPLICATION

EXTENDED

APPLICATION

FIELD FABRICATED WALL TERMINATION

A− Minimum clearance

above grade or average

snow accumulation

B− Maximum horizontal

separation between

intake and exhaust

C1 -Minimum from end of

exhaust to inlet of intake

C2 -Minimum from end of

exhaust to inlet of intake

D− Maximum exhaust

pipe length

E− Maximum wall support

distance from top of each

pipe (intake/exhaust)

See venting table 17 for maximum venting lengths with this arrangement.

* Use wall support every 24” (610 mm). Use two wall supports if extension is greater than 24” (610 mm) but less than 48” (1219 mm).

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

Intake Elbow

2” (51mm)

Vent Pipe

12” (305 mm)

6” (152 mm)

3” (76mm)

Vent Pipe

12” (305 mm)

6” (152 mm)6” (152 mm)

8” (203 mm)8” (203 mm)

6” (152 mm)6” (152 mm)

20” (508 mm)

6” (152 mm)

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

2” (51MM)

12”

The exhaust termination tee should be connected to the 2” or 3” PVC flue pipe as shown in the illustration. Do not use an accelerator in applications that include an exhaust termination tee. The accelerator is not required.

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

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

Intake Elbow

Intake and Exhaust

Intake

Front View of

Exhaust

A− Clearance above

grade or average snow

accumulation

B− Horizontal

separation between

intake and exhaust

C− Minimum from

end of exhaust to

inlet of intake

D− Exhaust pipe length

E− Wall support distance

from top of each pipe

(intake/exhaust)

Vent Pipe

12” (305 mm) Min. 12” (305 mm) Min.

6” (152 mm) Min. 24” (610 mm) Max.

9” (227 mm) Min.

12” (305 mm) Min. 16” (405 mm) Max.

6” (152 mm) Max.

3” (76MM)

Vent Pipe

6” (152 mm) Min. 24” (610 mm) Max.

9” (227 mm) Min. 12” (305 mm) Min.

20” (508 mm) Max.

6” (152 mm) Max.

FIGURE 38

Page 38

Page 39

Details of Exhaust Piping Terminations for Non‐Direct Vent Applications

Exhaust pipes may be routed either horizontally through an outside wall or vertically through the roof. In attic or closet installations, vertical termination through the roof is pre ferred. Figures 39 and 40 show typical terminations.

1. Exhaust piping must terminate straight out or up as shown. The termination pipe must be sized as listed in table 20. The specified pipe size ensures proper velocity required to move the exhaust gases away from the building.

2. On field supplied terminations for side wall exit, ex haust piping may extend a maximum of 12 inches (305MM) for 2” PVC and 20 inches (508MM) for 3” (76MM) PVC beyond the outside wall.

3. If exhaust piping must be run up a side wall to position above snow accumulation or other obstructions, pip ing must be supported every 24 inches (610MM). When exhaust piping must be run up an outside wall, any reduction in exhaust pipe size must be done after the final elbow.

4. Distance between exhaust pipe terminations on mul tiple furnaces must meet local codes.

EL296UHE NON-DIRECT VENT APPLICATION

USING EXISTING CHIMNEY

SIZE TERMINATION

PIPE PER TABLE 20.

Minimum 12” (305MM)

above chimney top

plate or average snow

accumulation

SHEET

METAL TOP

PLATE

INSULATE

TO FORM

SEAL

STRAIGHT-CUT OR

ANGLE-CUT IN DIRECTION

OF ROOF SLOPE

EXHAUST VENT

1/2” (13MM)

WEATHERPROOF

INSULATION

SHOULDER OF FITTINGS

PROVIDE SUPPORT

OF PIPE ON TOP PLATE

EXTERIOR

PORTION OF

CHIMNEY

FIGURE 40

12” (305MM)

ABOVE AVE.

SNOW

ACCUMULATION

3” (76MM) OR

2” (51MM) PVC

PROVIDE SUPPORT

FOR EXHAUST LINES

1/2” (13MM) FOAM

INSULATION

NON-DIRECT VENT ROOF TERMINATION KIT

(15F75 or 44J41)

FIGURE 39

SIZE TERMINATION

PIPE PER TABLE

20.

UNCONDITIONED

ATTIC SPACE

Page 39

Page 40

Condensate Piping

This unit is designed for either right‐ or left‐side exit of con densate piping in upflow applications. In horizontal applica tions, the condensate trap must extend below the unit. An 8” service clearance is required for the condensate trap. Refer to figure 41 for condensate trap locations. Figure 49 shows trap assembly using 1/2” PVC or 3/4” PVC.

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

1 - Determine which side condensate piping will exit the

unit, location of trap, field-provided fittings and length of PVC pipe required to reach available drain.

2 - Use a large flat head screw driver or a 1/2” drive socket

extension and remove plug. Install provided 3/4 NPT street elbow fitting into cold end header box. Use Tef lon tape or appropriate pipe dope.

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

of the trap. Secure with clamp. See figure 49.

4 - Install drain trap using appropriate PVC fittings, glue

all joints. Glue the provided drain trap as shown in fig ures 49. Route the condensate line to an open drain.

Condensate line must maintain a 1/4” downward slope from the furnace to the drain.

CONDENSATE TRAP AND PLUG LOCATIONS

(Unit shown in upflow position)

Trap

(same on

right side)

1-1/2 in.

Plug

(same on left side)

5 - Figures 44 and 46 show the furnace and evaporator

coil using a separate drain. If necessary the conden sate line from the furnace and evaporator coil can drain together. See figures, 45, 47 and 48. Upflow furnace (figure 47) - In upflow furnace applica tions the field provided vent must be a minimum 1” to a maximum 2” length above the condensate drain outlet connection. Any length above 2” may result in a flooded heat exchanger if the combined primary drain line were to become restricted. Horizontal furnace (figure 48) - In horizontal furnace applications the field provided vent must be a mini mum 4” to a maximum 5” length above the condensate drain outlet connection. Any length above 5” may re sult in a flooded heat exchanger if the combined pri mary drain line were to become restricted.

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

NOTE - Appropriately sized tubing and barbed fitting may be used for condensate drain. Attach to the drain on the trap using a hose clamp. See figure 42.

Field Provided Drain Components

Elbow

Barbed Fitting

Tubing

Hose Clamp

FIGURE 42

NOTE - In upflow applications where side return air filter is installed on same side as the conden sate trap, filter rack must be installed beyond condensate trap or trap must be re-located to avoid interference.

FIGURE 41

CAUTION

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

6 - If unit will be started immediately upon completion of

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

Condensate line must slope downward away from the trap to drain. If drain level is above condensate trap, condensate pump must be used. Condensate drain line should be routed within the conditioned space to avoid freezing of condensate and blockage of drain line. If this is not possible, a heat cable kit may be used

Page 40

Page 41

on the condensate trap and line. Heating cable kit is available from Lennox in various lengths; 6 ft. (1.8m) kit no. 26K68; 24 ft. (7.3m) - kit no. 26K69; and 50 ft. (15.2m) - kit no. 26K70.

CONDENSATE TRAP LOCATIONS

(Unit shown in upflow position with remote trap)

Condensate Trap With Optional Overflow Switch

From Evaporator Coil

HorizontalFurnace4”Min.to 5”Max.above

condensatedrainconnection)

FieldProvidedVent

Min.1” AboveCondensate

Drain

Connection

1”

Min.

2”Max.

*5’ max.

PVCPipeOnly

To Drain

*Piping from furnace must slope down a minimum of 1/4” per ft. toward trap.

FIGURE 43

EL29UHE With Evaporator Coil Using A Separate Drain

Evaporator drain

line required

FurnaceCondensate

DrainConnection

Optional

FIGURE 45

Field Provided Vent (1” min. 2” max. above condensate connec tion)

Condensate

Drain

Connection

FIGURE 44

Page 41

Page 42

EL296UHE with Evaporator Coil Using a Separate Drain

(Unit shown in horizontal left-hand discharge position)

Pan

Drain

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

EL296UHE with Evaporator Coil Using a Common Drain

(1”min.to 2”Max.above

condensate drain connection)

Evaporator

Coil

Condensate

DrainConnection

FIGURE 46

Evaporator

drain line re

quired

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

4”min

5”max

5’ max.

PVC Pipe Only

IMPORTANT

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

Condensate

DrainConnection

FIGURE 47

EL296UHE with Evaporator Coil Using a Common Drain

Evaporator

Coil

(Unit shown in horizontal left−hand discharge position)

(4”min.to 5”Max.above

condensate drain connection)

4”min

5”max

5’ max.

PVC Pipe Only

CondensateDrain

Connection

Pan

Drain

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

FIGURE 48

Page 42

Page 43

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

Optional Condensate Drain Connection

Adapter 3/4 inch slip X

3/4 inch mpt (not furnished)

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

Condensate Drain

Connection In Unit

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

Trap

OptionalDrainPipingFromTrap

Drain Assembly for 1/2 inch Drain Pipe

1/2 inch PVC Pipe

(Not Furnished)

90° Elbow

1/2 inch PVC

(Not Furnished)

Drain

Drain Assembly for 3/4 inch Drain Pipe

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

Elbow 3/4 inch PVC

90°

(Not Furnished)

1/2 inch PVC Pipe

(Not Furnished)

Adapter 3/4 inch slip X

3/4 inch mpt (not furnished)

ent

5 Feet

Maximum

3/4 inch PVC Pipe

(Not Furnished)

Coupling 3/4 inch slip X slip

(Not Furnished)

Drain Trap

Assembly

(Furnished)

Condensate Drain

Connection In Unit

90° Elbow

3/4 inch PVC

(Not Furnished)

Drain

DrainTrapAssembly

(Furnished)

(178)

Drain Trap

Clean Out

90° Elbow

3/4 inch PVC

(Not Furnished)

Coupling 3/4 inch slip X slip

Drain

DrainTrap Assembly with 1/2 inch Piping 1 (25 mm) Min. 2 (50 mm) Max. Above Top

Of Condensate Drain Connection In Unit

(Not Furnished)

Vent

1/2 inch

Condensate Drain

Connection In Unit

Drain

DrainTrap Assembly with 3/4 inch Piping

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

Vent

3/4 inch

Condensate Drain Connection In Unit

Drain

FIGURE 49

Page 43

Page 44

III-START‐UP

A-Preliminary and Seasonal Checks

1 - Inspect electrical wiring, both field and factory installed

for loose connections. Tighten as required.

2 - Check voltage at disconnect switch. Voltage must be

within range listed on the nameplate. If not, consult the power company and have voltage condition corrected before starting unit.

3 - Inspect condition of condensate traps and drain as

sembly. Disassemble and clean seasonally.

B-Heating Start‐Up

BEFORE LIGHTING the unit, smell all around the furnace

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 EL296UHE is equipped with a gas control switch. Use only your hand to move the switch. Nev er use tools. If the the switch will not move by hand, replace the valve. Do not try to repair it. Force or attempted repair may result in a fire or explosion.

Placing the furnace into operation:

EL296UHE units are equipped with a SureLight system. Do not

attempt to manually light burners on this

ignition

furnace. Each time the thermostat calls for heat, the burn ers will automatically light The ignitor does not get hot when there is no call for heat on units with SureLight ignition sys tem.

Priming Condensate Trap

The condensate trap should be primed with water prior to start-up to ensure proper condensate drainage. Either pour 10 fl. oz. (300 ml) of water into the trap, or follow these steps to prime the trap:

1 - Follow the lighting instructions to place the unit into op

eration.

2 - Set the thermostat to initiate a heating demand.

3 - Allow the burners to fire for approximately 3 minutes. 4 - Adjust the thermostat to deactivate the heating de

mand.

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

thermostat to initiate a heating demand and again al low the burners to fire for approximately 3 minutes.

6 - Adjust the thermostat to deactivate the heating de

mand and again wait for the combustion air inducer to stop. At this point, the trap should be primed with suffi cient water to ensure proper condensate drain opera tion.

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 50)

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 gas valve switch to OFF. See figure 50. 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 instruc tions. If you do not smell gas go to next step.

8 - Move gas valve switch to ON. See figure 50.

INLET PRESSURE POST

GAS VALVE SHOWN IN ON POSITION

MANIFOLD

PRESSURE POST

HIGH FIRE ADJUSTMENT

SCREW

(under cap)

FIGURE 50

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 techni cian 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 gas valve switch to OFF. 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 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 lockout? If the unit locks

out again, inspect the unit for blockages.

Page 44

Page 45

IV-HEATING SYSTEM SERVICE CHECKS

A-CSA Certification

All units are CSA design certified without modifications. Refer to the EL296UHE Installation Instruction.

B-Gas Piping

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.

WARNING

Do not exceed 600 in-lbs (50 ft-lbs) torque when attaching the gas piping to the gas valve.

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.

Compounds used on gas piping threaded joints should be resistant to action of liquefied petroleum gases.

C-Testing Gas Piping

IMPORTANT

In case emergency shutdown is required, turn off the main shut‐off valve and disconnect the main power to unit. These controls should be properly labeled by the installer.

When pressure testing gas lines, the gas valve must be dis connected and isolated. Gas valves can be damaged if subjected to more than 0.5 psig (14” W.C.). See figure 51. If the pressure is greater than 0.5psig (14”W.C.), use the manual shut-off valve before pressure testing to isolate fur nace from gas supply.

GAS PIPING TEST PROCEDURE

MANUAL MAIN SHUT-OFF VALVE

WILL NOT HOLD TEST PRESSURE

IN EXCESS OF 0.5 PSIG (14”W.C.)

When checking piping connections for gas leaks, use pre ferred means. Kitchen detergents can cause harmful cor rosion on various metals used in gas piping. Use of a spe cialty Gas Leak Detector is strongly recommended. It is available through Lennox under part number 31B2001. See Corp. 8411-L10, for further details.

Do not use matches, candles, flame or any other source of ignition to check for gas leaks.

D-Testing Gas Supply Pressure

An inlet post located on the gas valve provides access to the supply pressure. See figure 50. 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 23 for supply line pressure.

E-Check Manifold Pressure

A manifold pressure post located on the gas valve provides access to the manifold pressure. See figure 50. Back out the 3/32 hex screw one turn. Follow the steps below and use figure 52 as a reference. Gas manifold Kit 10L34 pro vides additional components if needed

1 - Connect the 5/16” round tubing to the manifold post.

Secure with the clamp.

2 - Connect the reducer fitting to the 5/16” round tubing

followed by a piece of 10” length square tubing.

3 - Connect the other end of the square tubing to the “+”

positive side of the measuring device.

4 - Take the 2” length square tubing, tee, 10” length of

square tubing and tee into the gas valve regulator vent hose. Connect to the measuring device negative “-” side.

5 - Ignite unit on low fire and let run for 5 minutes to allow

for steady state conditions.

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

manifold pressure and compare to value given in table

23.

7 - If necessary, make adjustments. Figure 50 shows

location of high fire and low fire adjustment screws.

6 - Repeat steps 5, 6 and 7 on high fire. See values in

table 23.

1/8 NPT PLUG

GAS VALVE

FIGURE 51

CAP

IMPORTANT

For safety, connect a shut‐off valve between the ma nometer and the gas tap to permit shut off of gas pressure to the manometer.

NOTE - Shut unit off and remove manometer as soon as an accurate reading has been obtained. Re-start unit and check gas valve for gas leaks.

Page 45

Page 46

MANIFOLD PRESSURE CHECK SET UP

5/16” Round

Reducer

Fitting

Hose

Manifold Post

Clamp

10” Long

Square Tubing

Gas Valve Regulator

Vent Hose

(to burner box)

2” Long

Square Tubing

Tee

Measuring Device

FIGURE 52

F- Proper Gas Flow (Approximate)

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 21 below. If manifold pressure matches table 21 and rate is incorrect, check gas orifices for proper size and restriction.

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

TABLE 21

GAS METER CLOCKING CHART

Seconds for One Revolution

EL296

Unit

-045 80 160 200 400

-70 55 110 136 272

-90 41 82 102 204

-110 33 66 82 164

-135 27 54 68 136

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

Natural LP

1 cu ft

Dial

2 cu ft

Dial

1 cu ft

Dial

2 cu ft

DIAL

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.

G- Proper Combustion

Furnace should operate minimum 15 minutes with correct manifold pressure and gas flow rate before checking com bustion. See sections E- and F-. Take combustion sample beyond the flue outlet. Table 22 shows acceptable com bustions. The maximum carbon monoxide reading should not exceed 50 ppm.

TABLE 22

EL296 Model

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

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

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

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

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

The maximum carbon monoxide reading should not exceed 50 ppm.

H- High Altitude

The manifold pressure, gas orifice and pressure switch

may require adjustment or replacement to ensure proper

operation at higher altitudes. See table 23 or 24 for man

ifold pressures and table 25 for gas conversion and pres

sure switch kits.

CO2%

Low Fire High Fire Low Fire High Fire

For Nat

CO2%

For L.P

Page 46

Page 47

TABLE 23

Manifold and Supply Line Pressure 0-10,000ft. For -1 Units

EL296

Unit

Gas

Manifold Pressure in.wg. Supply Line Pressure in. w.g.

Low Fire High Fire Min Max

Natural 1.7 3.5 4.5 13.0

All Sizes

NOTE -

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

procedure.

LP/propane 4.9 10.0 11.0 13.0

TABLE 24

Manifold and Supply Line Pressure 0-10,000ft. For -2 Units and Later

Manifold Pressure in. wg.

EL296

Unit

All

Sizes

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

Gas

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

LP/propane 4.9 10.0 4.6 9.4 4.4 9.1 4.3 8.9 4.9 10.0 11.0 13.0

0-4500 ft. 4501-5500 ft. 5501-6500 ft. 6501 - 7500ft. 7501 - 10000ft.

Low

Fire

High

Fire

Low

Fire

High

Fire

Low

Fire

High

Fire

Low

Fire

High

Fire

Low

Fire

High

Fire

Supply Line

Pressure

in. w.g.

0 - 10000 ft.

Min Max

TABLE 25

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

EL296

Unit

-045

Natural to

LP/Propane

0 - 7500 ft

(0 - 2286m)

High Altitude

Natural Burner

Orifice Kit

7501 - 10,000 ft

(2286 - 3038m)

High Altitude

LP/Propane Burner

Orifice Kit

7501 - 10,000 ft

(2286 - 3038m)

High Altitude Pressure Switch

4501 - 7500 ft

(1373 - 2286m)

7501 -10,000 ft (2286 - 3048m)

93W81 93W84

-070 93W80 93W85

-090 93W82 93W80

*78W93 73W37 *78W96

-110 93W80 93W85

-135 93W83 93W85

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

Page 47

Page 48

I- Proper Ground and Voltage

Furnace must be properly grounded for proper perform ance. Use the following procedure to check for ground and voltage to the integrated control.

1 - Measure the AC voltage between Line Neutral (spade

terminals) and “C” terminal (low voltage terminal block) on the integrated control. See figure 53. A wide variation in the voltage between Line Neutral and “C” as a function of load indicates a poor or partial ground. Compare the readings to the table below. If the read ings exceed the maximum shown in table 26, make re pairs before operating the furnace.

2 - In addition, measure the AC voltage from Line Hot to

Line Neutral (spade terminals) on the integrated con trol. See figure 53. This voltage should be in the range of 97 to 132 Vac

TABLE 26

Furnace Status

Power On Furnace Idle 0.3 2

CAI / Ignitor Energized 0.75 5

Indoor Blower Energized Less than 2 10

Measurement VAC

Expected Maximum

CHECK VOLTAGE BETWEEN LINE NEUTRAL

AND LOW VOLTAGE “C” TERMINAL

CHECK VOLTAGE BETWEEN LINE HOT

AND LINE NEUTRAL

FIGURE 53

Page 48

Page 49

V-TYPICAL OPERATING CHARACTERISTICS

A-Blower Operation and Adjustment

1 - Blower operation is dependent on thermostat control

system.

2 - Generally, blower operation is set at thermostat sub

base fan switch. With fan switch in ON position, blower operates continuously. With fan switch in AUTO posi tion, blower cycles with demand or runs continuously while heating or cooling circuit cycles.

3 - Depending on the type of indoor thermostat, blower

and entire unit will be off when the system switch is in OFF position.

B-Temperature Rise (Figure 54)

Temperature rise for EL296UHE units depends on unit in put, blower speed, blower horsepower and static pressure as marked on the unit rating plate. The blower speed must be set for unit operation within the range of “TEMP. RISE °F” listed on the unit rating plate.

TEMPERATURE RISE

Supply Duct Temperature ________

Return Duct Temperature

Temperature Rise = ________

_____

C-External Static Pressure

1 - Tap locations shown in figure 55. 2 - Punch a 1/4” diameter hole in supply and return air ple

nums. Insert manometer hose flush with inside edge of hole or insulation. Seal around the hose with perma gum. Connect the zero end of the manometer to the discharge (supply) side of the system. On ducted sys tems, connect the other end of manometer to the return duct as above.

3 - With only the blower motor running and the evaporator

coil dry, observe the manometer reading. Adjust blow er motor speed to deliver the air desired according to the job requirements. For heating speed (second stage heat speed) external static pressure drop must not be more than 0.5” W.C. For cooling speed (second stage cool speed) external static pressure drop must not be more than 0.5” W.C.

4 - Seal the hole when the check is complete.

EXTERNAL STATIC PRESSURE

Supply Duct Static ________

Return Duct Static + _____

Total Duct Static = ________ (dry coil)

FIGURE 54

SUPPLY

AIR

Temperature s

RETURN AIR

Supply Air

Return Air

FIGURE 55

Duct Static

Page 49

Page 50

VI-MAINTENANCE

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 opera tion, serious injury, death, or property damage. Before servicing, disconnect all electrical power to furnace. When servicing controls, label all wires prior to dis connecting. Take care to reconnect wires correctly. Verify proper operation after servicing.

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

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.

TABLE 27

Furnace

Cabinet Width

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

21” 16 X 25 X 1 (1) 20 X 25 X 1 (1)

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

Exhaust and air intake pipes

Check the exhaust and air intake pipes and all connections for tightness and to make sure there is no blockage.

NOTE - After any heavy snow, ice or frozen fog event the furnace vent pipes may become restricted. Always check the vent system and remove any snow or ice that may be obstructing the plastic intake or exhaust pipes.

Electrical

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

operating).

3 - Check amp-draw on the blower motor.

Motor Nameplate__________Actual__________

Winterizing and Condensate Trap Care

1 - Turn off power to the furnace.

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

3 - Remove the clean out cap from the condensate trap

and empty water. Inspect the trap then reinstall the clean out cap.

Side Return Bottom Return

Filter Size

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 inju ry or death.

Filters

All air filters are installed external to the unit. Filters should be inspected monthly. Clean or replace the filters when necessary to ensure proper furnace operation. Table 27 lists recommended filter sizes.

IMPORTANT

If a highefficiency filter is being installed as part of this system to ensure better indoor air quality, the fil ter must be properly sized. Highefficiency filters have a higher static pressure drop than standardef ficiency glass/foam filters. If the pressure drop is too great, system capacity and performance may be re duced. The pressure drop may also cause the limit to trip more frequently during the winter and the indoor coil to freeze in the summer, resulting in an increase in the number of service calls.

Before using any filter with this system, check the specifications provided by the filter manufacturer against the data given in the appropriate Lennox Product Specifications bulletin. Additional informa tion is provided in Service and Application Note ACC002 (August 2000).

Condensate Hose Screens (Figure 56)

Check the condensate hose screens for blockage and

clean if necessary. 1 - Turn off power to the unit. 2 - Remove hoses from cold end header box. Twist and

pull screens to remove. 3 - Inspect screens and rinse with tap water if needed. 4 - Reinstall screens, reconnect hoses and turn on power

to unit.

Condensate Hose Screens

Hose

FIGURE 56

Cleaning Heat Exchanger

If cleaning the heat exchanger becomes necessary, follow the below procedures and refer to figure 1 when disassem bling unit. Use papers or protective covering in front of fur nace while removing heat exchanger assembly.

1 - Turn off electrical and gas supplies to the furnace. 2 - Remove the furnace access panels. 3 - Disconnect the wires from the gas valve. 4 - Remove gas supply line connected to gas valve. Re

move the burner box cover (if equipped) and remove gas valve/manifold assembly.

Hose

Page 50

Page 51

5 - Remove sensor wire from sensor. Disconnect 2‐pin

plug from the ignitor. 6 - Disconnect wires from flame roll-out switches. 7 - Disconnect combustion air intake pipe. It may be nec

essary to cut the existing pipe to remove burner box

assembly. 8 - Remove four burner box screws at the vestibule panel

and remove burner box. Set burner box assembly

aside.

NOTE - If necessary, clean burners at this time. Follow

procedures outlined in Burner Cleaning section.

9 - Loosen the clamps to the flexible exhaust coupling. 10 - Disconnect condensate drain line from the cold end

header box. 11 - Disconnect condensate drain tubing from flue collar.

Remove screws that secures the flue collar into place.

Remove flue collar. It may be necessary to cut the exit

ing exhaust pipe for removal of the fitting. 12 - Mark and disconnect all combustion air pressure tub

ing from cold end header collector box. 13 - Mark and remove wires from pressure switch assemb

ly. Remove the assembly. Keep tubing attached to

pressure switches. 14 - Disconnect the plug from the combustion air inducer.

Remove two screws which secure combustion air in

ducer to collector box. Remove combustion air induc

er assembly. Remove ground wire from vest panel. 15 - Disconnect the condensate drain line. 16 - Remove cold end header box. 17 - Remove electrical junction box from the side of the fur

nace. 18 - Mark and disconnect any remaining wiring to heating

compartment components. Disengage strain relief

bushing and pull wiring and bushing through the hole

in the blower deck. 19 - Remove the primary limit from the vestibule panel. 20 - Remove two screws from the front cabinet flange at

the blower deck. Spread cabinet sides slightly to allow

clearance for removal of heat exchanger. 21 - Remove screws along vestibule sides and bottom

which secure vestibule panel and heat exchanger as

sembly to cabinet. Remove two screws from blower

rail which secure bottom heat exchanger flange. Re

move heat exchanger from furnace cabinet. 22 - Back wash heat exchanger with soapy water solution

or steam. If steam is used it must be below 275°F

(135°C) .

23 - Thoroughly rinse and drain the heat exchanger. Soap

solutions can be corrosive. Take care to rinse entire

assembly. 24 - Reinstall heat exchanger into cabinet making sure that

the clamshells of the heat exchanger assembly is en

gaged properly into the support bracket on the blower

deck. Remove the indoor blower to view this area

through the blower opening.

25 - Re‐secure the supporting screws along the vestibule

sides and bottom to the cabinet.

26 - Reinstall cabinet screws on front flange at blower

deck. 27 - Reinstall the primary limit on the vestibule panel. 28 - Route heating component wiring through hole in blow

er deck and reinsert strain relief bushing. 29 - Reinstall electrical junction box. 30 - Reinstall the cold end header box. 31 - Reinstall the combustion air inducer. Reconnect the

plug to the wire harness. 32 - Reinstall pressure switches and reconnect pressure

switch wiring. 33 - Carefully connect combustion air pressure switch tub

ing from pressure switches to proper ports on cold end

header collector box. 34 - Reconnect condensate drain line to the cold end

header box. 35 - Use securing screws to reinstall flue collar to the top

cap on the furnace. Reconnect exhaust piping and ex

haust drain tubing. 36 - Replace flexible exhaust adapter on combustion air in

ducer and flue collar. Secure using two existing hose

clamps. 37 - Reinstall burner box assembly in vestibule area. Se

cure burner box assembly to vestibule panel using

four existing screws. Make sure burners line up in

center of burner ports

38 - Reconnect flame roll-out switch wires. 39 - Reconnect sensor wire and reconnect 2-pin plug from

ignitor. 40 - Reinstall gas valve manifold assembly. Reconnect

gas supply line to gas valve. 41 - Reconnect the combustion air intake pipe. 42 - Reinstall burner box cover. 43 - Reconnect wires to gas valve. 44 - Replace the blower compartment access panel. 45 - Reconnect gas supply piping. Turn on power and gas

supply to unit. 46- Follow lighting instructions on unit nameplate to light

and operate furnace for 5 minutes to ensure the fur

nace is operating properly. 47- Check all piping connections, factory and field, for gas

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

48- Replace heating compartment access panel.

CAUTION

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

Page 51

Page 52

Cleaning the Burner Assembly (if needed)

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

Remove upper and lower furnace access panels. 2 - Disconnect the wires from the gas valve. 3 - Remove the burner box cover (if equipped). 4 - Disconnect the gas supply line from the gas valve. Re

move gas valve/manifold assembly. 5 - Mark and disconnect sensor wire from the sensor. Dis

connect wires from flame rollout switches. 6 - Disconnect combustion air intake pipe. It may be nec

essary to cut the existing pipe to remove burner box

assembly. 7 - Remove four screws which secure burner box assem

bly to vest panel. Remove burner box from the unit. 8 - Use the soft brush attachment on a vacuum cleaner to

gently clean the face of the burners. Visually inspect

the inside of the burners and crossovers for any block

age caused by foreign matter. Remove any blockage.

9 - Reinstall the burner box assembly using the existing

four screws. Make sure that the burners line up in the center of the burner ports.

10 - Reconnect the sensor wire and reconnect the 2-pin

plug to the ignitor wiring harness. Reconnect wires to flame rollout switches.

11 - Reinstall the gas valve manifold assembly. Reconnect

the gas supply line to the gas valve. Reinstall the burn er box cover.

12 - Reconnect wires to gas valve.

13 - Replace the blower compartment access panel.

14 - Refer to instruction on verifying gas and electrical con

nections when re-establishing supplies.

15 - Follow lighting instructions to light and operate fur

nace for 5 minutes to ensure that heat exchanger is clean and dry and that furnace is operating properly.

16 - Replace heating compartment access panel.

Page 52

Page 53

VII- Wiring and Sequence of Operation

Page 53

Page 54

Electronic Ignition

The two-stage, variable speed integrated control used in EL296UHE units has an added feature of an internal Watchguard control. The feature serves as an automatic reset device for ignition control lockout caused by ignition failure. After one hour of continuous thermostat demand for heat, the Watchguard will break and remake thermostat demand to the furnace and automatically reset the control to begin the ignition sequence.

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

Applications Using a Two-Stage Thermostat

See figure 57 for ignition control sequence

A - Heating Sequence -- Integrated Control Thermostat Selection DIP Switch 1 OFF in “Two-Stage” Position (Factory Setting)

1. On a call for heat, thermostat first-stage contacts close

sending a signal to the integrated control. The inte

grated control runs a self‐diagnostic program and

checks high temperature limit switches for normally

closed contacts and pressure switches for normally

open contacts. The combustion air inducer is ener

gized at low speed.

2. Once the control receives a signal that the low pres

sure switch has closed, the combustion air inducer be

gins a 15-second pre-purge in low speed.

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..

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

nitor warm-up period begins. The combustion air in

ducer continues to operate at low speed. 4 - After the 20-second warm-up period has ended, the

gas valve is energized on low fire (first stage) and igni

tion occurs. At the same time, the control module

sends a signal to begin an indoor blower 30-second

ON-delay. When the delay ends, the indoor blower motor is energized on the low fire heating speed, the HUM contacts close energizing the humidifier and 120V ACC terminal is energized. The furnace will con tinue this operation as long as the thermostat has a first-stage heating demand.

NOTE - If the indoor thermostat is set on CONTINU

OUS FAN ON mode, the furnace will light on high fire (second-stage) for 60 seconds to improve heat ex changer warm up. After 60 second warm-up period, furnace will switch to low fire (first-stage).

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

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

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

trol energizes the combustion air inducer at high speed. The control also checks the high fire (second stage) pressure switch to make sure it is closed. The high fire (second stage) gas valve is energized and the indoor blower motor is energized for operation at the high fire heating speed.

7 - When the demand for high fire (second stage) heat is

satisfied, the combustion air inducer is switched to the low-fire heating speed and the high-fire (second stage) gas valve is de-energized. The low-fire (first stage) gas valve continues operation. The indoor blower motor is switched to the low-fire heating speed.

8 - When the thermostat demand for low-fire (first stage)

heat is satisfied, the gas valve is de-energized and the field-selected indoor blower off delay begins. The combustion air inducer begins a 5-second post-purge period.

9 - When the combustion air post-purge period is com

plete, the inducer and the HUM contacts are de-ener gized. The indoor blower is de-energized at the end of the off delay as well a s the 120V ACC terminal.

Page 54

Page 55

Applications Using A Single-Stage Thermostat

See figure 58 for ignition control sequence

B - Heating Sequence -- Integrated Control Thermostat Selection DIP Switch 1 ON in “Single-Stage” Position

NOTE - In these applications, two-stage heat will be initi ated by the integrated control if heating demand has not been satisfied after the field adjustable period (7 or 12 min utes).

1. On a call for heat, thermostat first-stage contacts close sending a signal to the integrated control. The inte grated control runs a self‐diagnostic program and checks high temperature limit switches for normally closed contacts and pressure switches for normally open contacts. The combustion air inducer is ener gized at low speed.

2. Once the control receives a signal that the low pres sure switch has closed, the combustion air inducer be gins a 15-second pre-purge in low speed.

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.

3. After the pre-purge is complete, a 20-second initial ig nitor warm-up period begins. The combustion air in ducer continues to operate at low speed.

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

gas valve is energized on low fire (first stage) and igni tion occurs. At the same time, the control module sends a signal to begin an indoor blower 30-second ON-delay. When the delay ends, the indoor blower motor is energized on the low fire heating speed and the HUM contacts are energized. The integrated con trol also initiates a second-stage on delay (factory-set at 7 minutes; adjustable to 12 minutes).

5 - If the heating demand continues beyond the second-

stage on delay, the integrated control energizes the combustion air inducer at high speed. The control also checks the high fire (second stage) pressure switch to make sure it is closed. The high fire (second stage) gas valve is energized and the indoor blower motor is energized for operation at the high fire heating speed.

6 - When the thermostat heating demand is satisfied, the

combustion air inducer begins a 5-second low speed post-purge. The field-selected indoor blower off delay begins. The indoor blower operates at the low-fire heating speed.

7 - When the combustion air post-purge period is com

plete, the inducer and the HUM contacts are de-ener gized. The indoor blower is de-energized at the end of the off delay as well as the 120V ACC terminal.

OFF

1 stg heat demand

low speed CAI ignitor

low fire gas valve

indoor blower low heat

2 stg heat demand high speed CAI high fire gas valve

indoor blower high heat

OFF

heat demand

low speed CAI ignitor

low fire gas valve

indoor blower low heat

HEATING OPERATION WITH TWO-STAGE THERMOSTAT

Pre-Purge

Ignitor Warm-up

351

30 seconds

30 second

Trial For Ignition

RECOGNITION PERIOD

blower

“on” delay

FIGURE 57

HEATING OPERATION WITH SINGLE STAGE THERMOSTAT

Pre-Purge

Ignitor Warm-up

351

Trial For Ignition

30 second

blower

“on” delay

5 SEC80

Post

Purge

5 SEC80

Post

Purge

blower

“off”

delay

blower

“off”

delay

7 or 12 minutes after heating demand begins, furnace switches to high fire (depending on setting)

high speed CAI high fire gas valve

indoor blower high heat

FIGURE 58

Page 55

Page 56

VIII- EL296UHE Field Wiring Applications

EL296 Field Wiring Applications

DIP Switch Settings and On-Board Links (See figure 4)

Thermostat

1 Heat / 1 Cool

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

DIP Switch 1

Thermostat

Heating

Stages

On Board Links Must Be Cut To Select

System Options

DO NOT CUT ANY ON-BOARD LINKS

TABLE 28

Wiring Connections

T'STAT

*Not required on all units

FURNACE

TERM. STRIP

OUTDOOR

UNIT

1 Heat / 2 Cool

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

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

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

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

CUT ON-BOARD LINK

W914

DEHUM

T'STAT

*Not required on all units

T'STAT

*Not required on all units

FURNACE

TERM. STRIP

FURNACE

TERM. STRIP

OUTDOOR

UNIT

OUTDOOR

UNIT

Page 56

Page 57

DIP Switch Settings and On-Board Links (See figure 4)

DIP Switch 1

Thermostat

Heating

Stages

2 Heat / 2 Cool OFF

TABLE 28

EL296 Field Wiring Applications (Continued)

On Board Links Must Be Cut To Select

System Options

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

DEHUM

Wiring Connections

T'STAT

*Not required on all units

FURNACE

TERM. STRIP

OUTDOOR

UNIT

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

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

OFF

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

CUT ON-BOARD LINK

W914

DEHUM

CUT ON-BOARD LINK

W914

DEHUM

T'STAT

*Not required on all units

T'STAT

*Not required on all units

FURNACE

TERM. STRIP

FURNACE

TERM. STRIP

OUTDOOR

UNIT

OUTDOOR

UNIT

2 Heat / 1 Cool OFF

DO NOT CUT ANY ON-BOARD LINKS

Page 57

DEHUM

T'STAT

*Not required on all units

FURNACE

TERM. STRIP

OUTDOOR

UNIT

Page 58

Thermostat

Dual Fuel Single Stage Heat Pump

ComfortSense 7000 L7724U thermostat w/ dual fuel capa bilities Capable of 2 stage gas heat control

TABLE 28

EL296 Field Wiring Applications (Continued)

DIP Switch Settings and On-Board Links (figure 4)

DIP Switch 1

Thermostat

Heating

On Board Links Must Be Cut To Select

System Options

Stages

OFF

CUT ON-BOARD LINK

W951 HEAT PUMP

DEHUM

L7724U T'STAT

Wiring Connections

FURNACE

TERM. STRIP

HEAT PUMP

67M41*

Dual Fuel Two Stage Heat Pump

ComfortSense

OFF

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

L7724U T'STAT

FURNACE

TERM. STRIP

HEAT PUMP

67M41*

7000 L7724U thermostat w/ dual fuel capa bilities Capable of 2 stage gas heat

CUT ON-BOARD LINK

W951 HEAT

PUMP

DEHUM

control

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

NOTE - Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the EL296 integrated control.

out blue

Page 58

Page 59

Thermostat

Dual Fuel Single Stage Heat Pump

ComfortSense 7000 L7742U thermostat w/ dual fuel capa bilities Capable of 2 stage gas heat control w/dehu midification control

TABLE 28

EL296 Field Wiring Applications (Continued)

DIP Switch Settings and On-Board Links (figure 4)

DIP Switch 1

Thermostat

Heating

On Board Links Must Be Cut To Select

System Options

Stages

OFF

CUT ON-BOARD LINK

W951 HEAT

PUMP

CUT ON-BOARD LINK

W914

DEHUM

Wiring Connections

L7742U T'STAT

TERM. STRIP

FURNACE

HEAT PUMP

67M41*

Dual Fuel Two Stage Heat Pump

ComfortSense 7000 L7742U thermostat w/ dual fuel capa bilities Capable of 2 stage gas heat

OFF

CUT ON-BOARD LINK

W915

2 STAGE

COMPR

CUT ON-BOARD LINK

W951 HEAT

PUMP

CUT ON-BOARD LINK

W914

DEHUM

L7742U T'STAT

FURNACE

TERM. STRIP

HEAT PUMP

67M41*

control w/dehu midification

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

NOTE - Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the EL296 integrated control.

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Page 60

IX- Troubleshooting

Troubleshooting: Heating Sequence of Operation

CALL FOR FIRST-STAGE HEAT

1ST STAGE GAS

VALVE ENERGIZED

IGNITION TRIAL

BEGINS (H.S.I. ON)

CALL FOR

1ST STAGE HEAT

(LOW FIRE)

HIGH

LIMIT SWITCH

CLOSED?

YES

ROLLOUT

CIRCUITS CLOSED?

YES

LOW

PRESSURE

SWITCH

OPEN?

YES

INDUCER ON

LOW SPEED

LOW

PRESSURE SWITCH

CLOSED WITHIN 120

SECONDS?

YES

PRE−PURGE

(15 SECONDS)

H.S.I. ON

(20 SECONDS)

HEAT FAN ON DELAY

TIMER STARTED

INDOOR BLOWER OFF AFTER

HEAT FAN OFF DELAY

(LOW HEAT SPEED)

ERROR

CODE

FLASHES

DE−ENERGIZE

GAS VALVE

ERROR CODE

FLASHES (AFTER

5 SECONDS)

LOW PRESSURE SWITCH OPENS

HIGH

PRESSURE

SWITCH

OPEN

BEFORE

INDUCER WAS

TURNED ON?

INDOOR BLOWER

ON(LOW HEAT

SPEED)

INDUCER ON

(HIGH SPEED) INDOOR BLOWER

ON (LOW HEAT

SPEED)

INTERPURGE

(15 SECONDS)

YES

LIMIT

SWITCH

CLOSED WITHIN 3

MINUTES?

ERROR

CODE

FLASHES

INDUCER TO HIGH SPEED−

ERROR CODE

FLASHES

AFTER HEAT FAN

OFF DELAY (LOW

ROLLOUT

CIRCUIT CLOSES

(MANUAL

RE−SET)

INDOOR BLOWER OFF AFTER HEAT OFF DELAY

HARD LOCKOUT − ERROR CODE FLASHES

LOW & HIGH

PRESSURE SWITCH

CLOSED WITHIN 30

SECONDS?

INDOOR

BLOWER OFF

HEAT SPEED)

INDUCER OFF

AFTER POST

PURGE

YES

WATCHGUARD − ERROR CODE FLASHES

YES

INDUCER OFF−

WAIT 5 MINUTES ERROR CODE

FLASHES

CALL

FOR HEAT

ENDS?

YES

INDOOR

BLOWER

ON?

YES

INDOOR

BLOWER

OFF AFTER

HEAT FAN

OFF DELAY

FLAME

SENSED WITHIN

4 SECONDS?

YES

H.S.I. OFF

INDOOR

BLOWER ON 30 SEC.

(LOW HEAT SPEED)

CALL FOR HEAT SATISFIED

GAS VALVE

DE−ENERGIZED

H.S.I. OFF

WATCHGUARD LOCKOUT AUTOMATICALLY RESETS AFTER ONE HOUR

HARD LOCKOUT REQUIRES THERMOSTAT RESET OR CYCLING OF POWER TO RESET THE LOCKOUT.

IN CASE HIGH SPEED INDUCER IS RUNNING AT THE TIME THE GAS VALVE GETS ENERGIZED,

2ND STAGE GAS VALVE IS ENERGIZED INSTEAD OF 1ST STAGE. 20 SECONDS AFTER FLAME IS SENSED, INDUCER SWITCHES TO LOW SPEED, AND GAS VALVE SWITCHES TO 1ST STAGE.

5TH

UNSUCCESSFUL

TRIAL?

POSTPURGE

YES

(5 SECONDS)

Page 60

INDUCER

OFF

WATCHGUARD − ERROR CODE FLASHES

Page 61

Troubleshooting: Heating Sequence of Operation (Continued)

CALL FOR SECOND-STAGE HEAT

2 STAGE THERMOSTAT

RECOGNITION DELAY

ONLY FOR 1ST

REQUEST FOR

2ND STAGE HEAT

CALL FOR 2ND STAGE HEAT

(30 SECONDS)

EXPIRED?

(HIGH FIRE)

YES

INDUCER SWITCHED

TO HIGH SPEED

HIGH

PRESSURE SWITCH

CLOSED WITHIN 10

SECONDS?

YES

2ND STAGE GAS VALVE

ENERGIZED

INDOOR BLOWER ENERGIZED

ON HIGH HEAT SPEED

SINGLE STAGE

THERMOSTAT

2ND STAGE

ON DELAY

EXPIRED?

YES

INDUCER SWITCHED

TO LOW SPEED

5 MINUTE DELAY

(ERROR CODE FLASHES)

CALL FOR HEAT SATISFIED

SYSTEM WILL ALWAYS LIGHT ON LOW FIIRE, EVEN IF 2ND STAGE HEAT IS IN PLACE.

WHEN USED WITH A SINGLE STAGE THERMOSTAT, SET SW1 TO THE ON POSITION IN DIP SWITCH S4.

IF THE HIGH FIRE PRESSURE SWITCH DOES NOT CLOSE WITHIN 5 ATTEMPTS, THE SYSTEM WILL OPERATE AT LOW FIRE FOR THE REMAINDER OF THE CALL FOR HEAT REQUEST.

Page 61

Page 62

Troubleshooting: Heating Sequence of Operation (Continued)

CALL FOR HEAT SATISFIED

FIRST-STAGE HEAT SECOND-STAGE HEAT

2 3

RUN MODE: 1ST OR 2ND STAGE CALL FOR HEAT.

ALL INPUTS MONITORED (LIMIT, PRESSURE, CALL FOR HEAT/COOL, FLAME LEVEL)

2ND STAGE HEAT

2ND STAGE

CALL FOR HEAT

SATISFIED?

YES

DE−ENERGIZE 2ND STAGE

GAS VALVE

INDUCER SPEED SWITCHED

TO LOW SPEED

INDOOR BLOWER SWITCHED

TO LOW HEAT SPEED

1ST STAGE HEAT

1ST STAGE

CALL FOR HEAT

SATISFIED?

YES

GAS VALVE

DE−ENERGIZED

INDUCER OFF AFTER

5 SECOND POST PURGE

INDOOR BLOWER OFF

AFTER FIELD SELECTABLE

OFF DELAY

Page 62

Page 63

Troubleshooting: Cooling Sequence of Operation (Continued)

CALL FOR COOLING

1ST STAGE COOLING

REQUEST RECEIVED

WAIT FOR COMPRESSOR TIMED

OFF DELAY TO EXPIRE

ENERGIZE 1ST STAGE COOLING CONTACTOR (COMPRESSOR & FAN)

INDOOR BLOWER

SECOND ON DELAY

ENERGIZE INDOOR BLOWER

(LOW COOLING MODE)

2ND STAGE COOLING

REQUEST?

YES

ENERGIZE 2ND STAGE COOLING CONTACTOR (COMPRESSOR & FAN)

2ND STAGE

COOLING REQUEST

STILL ACTIVE?

MAINTAIN INDOOR

BLOWER

(LOW COOLING MODE)

YES

ENERGIZE INDOOR BLOWER

(HIGH COOLING MODE)

YES

MAINTAIN INDOOR BLOWER

(HIGH COOLING MODE)

YES

1ST STAGE

COOLING REQUEST

STILL ACTIVE?

DE−ENERGIZE 2ND

STAGE COOLING

CONTACTOR

(COMPRESSOR & FAN)

1ST STAGE

COOLING REQUEST

STILL ACTIVE?

DE−ENERGIZE 1ST

STAGE COOLING

CONTACTOR

(COMPRESSOR & FAN)

DE−ENERGIZE INDOOR

BLOWER

YES

ENERGIZE AND MAINTAIN

INDOOR BLOWER AT

(LOW COOLING MODE)

CONTROL WILL NOT RESPOND TO A 2ND STAGE COOLING REQUEST UNLESS A 1ST STAGE COOLING REQUEST IS ACTIVE.

Page 63

Page 64

Troubleshooting: Continuous Fan Sequence of Operation

CALL FOR FAN

INDOOR BLOWER ON

CONTINUOUS FAN

SPEED

CALL FOR FAN

REMOVED?

YES

REQUEST

FOR COOLING

RECEIVED?

REQUEST

FOR HEAT

RECEIVED?

DE-ENERGIZE INDOOR

BLOWER

YES

MAINTAIN INDOOR

BLOWER AT

CONTINUOUS FAN

MAINTAIN INDOOR

BLOWER AT

CONTINUOUS FAN

MAINTAIN INDOOR

BLOWER AT

CONTINUOUS FAN

GO TO CALL FOR COOLING

GO TO CALL FOR 1ST STAGE HEAT

1 - If continuous fan is active, unit will light and run at high fire

for 60 seconds to improve heat exchanger warm up.

Page 64

Lennox EL296UH070XE36B, EL296UH135XE60D, EL296UH090XE48C, EL296UH110XE60C, EL296DFE Series Unit Information

Specifications and Main Features

Frequently Asked Questions

User Manual