Lennox EL296DFE Series User manual

Page 1
UNIT INFORMATIONUNIT INFORMATION
Service Literature
©2016 Lennox Industries, Inc.
WARNING
Improper installation, adjustment, alteration,
service or maintenance can cause property damage,
personal injury or loss of life. Installation and service
must be performed by a licensed professional HVAC
installer (or equivalent), service agency or the gas
supplier.
CAUTION
As with any mechanical equipment, contact with
sharp sheet metal edges can result in personal
injury. Take care while handling this equipment and
wear gloves and protective clothing.
EL296DFE series units are high e󰀩ciency condensing
gas furnaces used for downow applications only, manu-
factured with Lennox Duralok heat exchangers formed of
aluminized steel. EL296DFE units are available in heating
capacities of 44,000 to 110,000 Btuh and cooling applica-
tions up to 5 tons. Refer to Product Specications Manual
for proper sizing.
Units are factory equipped for use with natural gas. Kits
are available for conversion to LPG operation. EL296DFE
model units are equipped with the SureLight® two-stage
constant torque integrated control. EL296DFE unit meets
the California Nitrogen Oxides (NOx) Standards and Cal-
ifornia Seasonal E󰀩ciency requirements. All units use a
redundant gas valve to assure safety shut-o󰀨 as required
by C.S.A.
All specications in this manual are subject to change.
Procedures outlined in this manual are presented as a
recommendation only and do not supersede or replace lo-
cal or state codes. In the absence of local or state codes,
the guidelines and procedures outlined in this manual (ex-
cept where noted) are recommendations only and do not
constitute code.
TABLE OF CONTENTS
Specications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2
Blower Performance Data . . . . . . . . . . . . . . . . . . Page 4
I Unit Components . . . . . . . . . . . . . . . . . . . . . . . . Page 6
II Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 22
III Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 45
IV Heating System Service Checks . . . . . . . . . Page 46
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
EL296DFE
Corp 1247-L10
Revised 06/2021
EL296DFE SERIES UNITS

Page 2
SPECIFICATIONS
Gas
Heating
Performance
Model No. EL296DF045XE36BEL296DF070XE48BEL296DF090XE48CEL296DF110XE60C
AHRI Ref. No. 5625722 5625723 5940633 5625725
1 AFUE 96% 96% 96% 96%
High
Fire
Input - Btuh 44,000 66,000 88,000 110,000
Output - Btuh 43,000 64,000 85,000 106,000
Temperature rise range - °F 35-65 35-65 40-70 45-75
Gas Manifold Pressure (in. w.g.)
Nat. Gas / LPG/Propane
3.5 / 10.0 3.5 / 10.0 3.5 / 10.0 3.5 / 10.0
Low
Fire
Input - Btuh 29,000 43,000 57,000 72,000
Output - Btuh 28,000 42,000 55,000 70,000
Temperature rise range - °F 20 - 50 25 - 55 30 - 60 35 - 65
Gas Manifold Pressure (in. w.g.)
Nat. Gas / LPG/Propane
1.7 / 4.5 1.7 / 4.5 1.7 / 4.5 1.7 / 4.5
High static - in. w.g. 0.5 0.5 0.5 0.5
Connections
in.
Intake / Exhaust Pipe (PVC) 2 / 2 2 / 2 2 / 2 2 / 2
Gas pipe size IPS 1/2 1/2 1/2 1/2
Condensate Drain Trap (PVC pipe) - i.d. 3/4 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 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 3/4 slip x 3/4 MPT
Indoor
Blower
Wheel nom. diameter x width - in. 10 x 8 11-1/2 x 10 10 x 10 11 x 11
Motor Type DC Brushless DC Brushless DC Brushless DC Brushless
Motor output - hp 1/2 3/4 3/4 1
Tons of add-on cooling 1.5 - 3 2 - 4 2 - 4 3 - 5
Air Volume Range - cfm 485 - 1395 520 - 1770 760 - 1765 1045 - 2285
Electrical
Data
Voltage 120 volts - 60 hertz - 1 phase
Blower motor full load amps 6.8 8.4 8.4 10.9
Maximum overcurrent protection 15 15 15 15
Shipping Data lbs. - 1 package 134 145 163 175
NOTE - Filters and provisions for mounting are not furnished and must be eld provided.
1 Annual Fuel Utilization E󰀩ciency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces.

Page 3
OPTIONAL ACCESSORIES - ORDER SEPARATELY
“B” Width Models “C” Width Models
CABINET ACCESSORIES
Downow Combustible Flooring Base 11M60 11M61
High Performance Economizer (Commercial Only) 10U53 10U53
CONTROLS
Blower Relay Kit (for two-stage outdoor units) 85W66 85W66
Furnace Twinning Kit 16W72 16W72
iComfort®E30 Smart Wi-Fi Thermostat 20A65 20A65
Remote Outdoor Temperature Sensor X2658 X2658
Night Service Kit 10B39 10B39
CONDENSATE DRAIN KITS
Condensate Drain Heat Cable 6 ft. 26K68 26K68
24 ft. 26K69 26K69
Crawl Space Vent Drain Kit US 51W18 51W18
Canada 15Z70 15Z70
FILTERS
1 Downow Filter Cabinet 51W07 51W08
No. and Size of lter - in. (2) 16 x 20 x 1 (2) 16 x 20 x 1
TERMINATION KITS
See Installation Instructions for specic venting information.
Direct Vent Concentric US - 2 in. 71M80 69M29
3 in. - - - 60L46
Canada - 2 in. 44W92 44W92
3 in. - - - 44W93
Flush-Mount US - 2, 2-1/2 or 3 in. 51W11 51W11
Canada - 2, 2-1/2 or 3 in. 51W12 51W12
Wall - Close Couple US - 2 in. 22G44 - - -
3 in. 44J40 44J40
Wall - Close Couple WTK Canada - 2 in. 30G28 - - -
3 in. 81J20 81J20
Roof Termination Flashing Kit
(no vent pipe - 2 ashings)
2 in. 15F75 15F75
3 in. 44J41 44J41
VENTING
Flue Coupling 2 in. 17H92 17H92
2Left Side Vent Kit 2 or 3 in. 87W73 87W73
1 Cleanable polyurethane, frame-type lter.
2 NOTE - The curved exhaust pipe furnished with the Left Side Vent Kit counts as one additional 2 in. diameter 90° elbow. When using 3 in. diameter pipe, the furnished
curved exhaust pipe and eld provided ttings to transition from 2 in. to 3 in. count as 20 feet of equivalent pipe on all units.
NOTE - Termination Kits (44W92, 44W93, 30G28, 51W12, 81J20) and Crawl Space Vent Drain Kit (15Z70) are certied to ULC S636 standard for use in Canada only.

Page 4
BLOWER DATA
EL296DF045XE36B PERFORMANCE (Less Filter)
External
Static
Pressure
in. w.g.
Air Volume / Watts at Various Blower Speeds
High
(Black)
Medium-High
(Brown)
Medium
(Blue)
Medium-Low
(Yellow)
Low
(Red)
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.00 1395 335 1290 250 1190 195 910 105 865 95
0.10 1375 350 1245 260 1140 205 875 110 815 100
0.20 1320 360 1215 265 1090 215 825 120 785 110
0.30 1285 365 1165 270 1065 225 795 130 735 115
0.40 1275 375 1150 285 1025 230 750 135 705 120
0.50 1230 385 1095 295 985 240 705 145 650 125
0.60 1185 380 1060 300 935 245 655 150 605 135
0.70 N/A N/A 1020 310 915 250 590 150 545 140
0.80 N/A N/A 980 315 860 255 555 160 485 140
EL296DF070XE48B PERFORMANCE (Less Filter)
External
Static
Pressure
in. w.g.
Air Volume / Watts at Various Blower Speeds
High
(Black)
Medium-High
(Brown)
Medium
(Blue)
Medium-Low
(Yellow)
Low
(Red)
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.00 1770 510 1550 340 1355 220 1255 180 1035 115
0.10 1720 520 1510 355 1315 230 1200 185 980 105
0.20 1705 535 1470 365 1265 245 1165 195 895 110
0.30 1665 540 1430 380 1235 250 1120 205 835 120
0.40 1605 555 1390 395 1185 260 1070 210 775 130
0.50 1585 565 1335 400 1155 275 1015 225 690 140
0.60 1540 565 1300 410 1100 290 970 235 625 145
0.70 N/A N/A 1260 420 1050 295 915 245 570 150
0.80 N/A N/A 1220 430 1015 305 865 255 520 155
EL296DF090XE48C PERFORMANCE (Less Filter)
External
Static
Pressure
in. w.g.
Air Volume / Watts at Various Blower Speeds
High
(Black)
Medium-High
(Brown)
Medium
(Blue)
Medium-Low
(Yellow)
Low
(Red)
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.00 1765 395 1565 265 1410 210 1290 175 1180 135
0.10 1745 410 1510 280 1365 220 1265 185 1120 140
0.20 1685 425 1455 295 1310 235 1220 200 1080 150
0.30 1630 440 1415 310 1285 250 1165 210 1035 160
0.40 1620 450 1370 320 1245 255 1125 220 985 175
0.50 1570 465 1335 330 1185 265 1080 230 925 180
0.60 1540 470 1295 345 1145 280 1045 240 875 190
0.70 N/A N/A 1260 355 1110 295 990 255 825 200
0.80 N/A N/A 1210 370 1060 305 940 260 760 205
EL296DF110XE60C PERFORMANCE (Less Filter)
External
Static
Pressure
in. w.g.
Air Volume / Watts at Various Blower Speeds
High
(Black)
Medium-High
(Brown)
Medium
(Blue)
Medium-Low
(Yellow)
Low
(Red)
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.00 2285 640 1990 435 1805 330 1685 265 1480 195
0.10 2250 660 1965 450 1775 345 1630 280 1430 205
0.20 2185 675 1910 465 1720 360 1575 295 1360 215
0.30 2150 690 1850 485 1670 375 1525 310 1290 235
0.40 2085 710 1810 495 1605 395 1465 325 1255 245
0.50 2060 725 1765 515 1565 400 1420 335 1190 255
0.60 2005 745 1700 535 1510 420 1370 355 1160 270
0.70 1970 760 1665 550 1460 440 1325 370 1100 280
0.80 1910 775 1620 560 1420 450 1275 380 1045 295

Page 5
PARTS IDENTIFICATION
CONTROL BOX
(Includes integrated control,
transformer and door switch)
BAG ASSEMBLY
(shipping location)
CONSTANT
TORQUE BLOWER
MOTOR
(hidden)
OUTER
ACCESS
PANEL
COMBUSTION
AIR INDUCER
BURNER BOX ASSEMBLY
(includes sensor, rollout switches and ignitor) GAS VALVE
BLOWER DECK
COLD END HEADER BOX
PRIMARY LIMIT
DuralokPlusTM
HEAT EXCHANGER
ASSEMBLY
COMBUSTION AIR INDUCER
PRESSURE SWITCH
FIGURE 1

Page 6
I-UNIT COMPONENTS
EL296DFE unit components are shown in gure 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 (gure 2) found in the blower
section.
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can a󰀨ect
electronic 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
secondary.
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.
Transformer
Circuit Breaker
SureLight®
Integrated
Control
Interlock Switch
FIGURE 2
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 can be manually reset by pressing the
button on the face. See gure 3.
CIRCUIT BREAKER CB8
PRESS TO RESET
FIGURE 3
WARNING
Shock hazard.
Disconnect power before servicing. Integrated
control is not eld repairable. If control is inoperable,
simply replace entire control.
Can cause injury or death. Unsafe operation will
result if repair is attempted.
4. Integrated Control (A92)
Units are equipped with the SureLight® two-stage, inte-
grated control. The system consists of a ignition / blower
control (gures 4 and 5) with control pin designations in ta-
bles 1 and 2 and ignitor (gure 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
blower are controlled in response to various system inputs
such as thermostat signal, pressure and limit switch signal
and ame signal. The control features a seven-segment
LED display, indicating furnace status and error codes.
The LED ashes in single digits. For example using ta-
ble 4 under LIMIT CODE, an “E” followed by “2” followed
by “5” followed by “0”, the limit switch circuit is open. The
control also has two unpowered (dry) 1/4” contacts for a
humidier and a 120 volt accessory terminal. Both rated
at (1) one amp each.
Electronic Ignition
At the beginning of the heat cycle the integrated con-
trol monitors the rst stage and second stage combus-
tion air inducer pressure switch. The control will not be-
gin the heating cycle if the rst 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 rst stage
heat. However, if the second stage pressure switch closes
during the rst stage heat pre-purge, the control will allow
second stage heat. Once the rst stage pressure switch
is determined to be open, the combustion air inducer is
energized on low (rst stage) heat speed. When the di󰀨er-
ential in the pressure switch is great enough, the pressure
switch closes and a 15-second pre-purge begins

Page 7
After the 15-second pre-purge period, the SureLight ig-
nitor 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 ame is sensed. If igni-
tion is not proved during the 4-second period, the control
will try four more times with an inter purge and warm-up
time between trials of 35 seconds. After a total of ve trials
for ignition (including the initial trial), the control goes into
Watchguard- 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 re 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 igntion on high-
re. After 10 to 20 seconds of high re operation the unit
will switch to low re.
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 re on rst-stage heat. The combustion air in-
ducer 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, la-
beled 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 re on rststage 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 rst
and second stage heat, the unit will re on rst stage heat
and switch to second stage heat after 30 seconds of oper-
ation. See Sequence of Operation ow charts in the back
of this manual for more detail.
TABLE 1
SureLight®Control 5 Pin Terminal Designation
Pin # Function
1Ignitor
2Combustion 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
1Gas Valve Second Stage
2Pressure Switch Second Stage
3 Rolout Switch
4 Ground
5 24V Hot
6Primary Limit In
7 Gas Valve First Stage
8Gas Valve Common
924V Neutral
10 Ground
11 Primary Limit Out
12 Pressure Switch First Stage

Page 8
INTEGRATED CONTROL
THERMOSTAT CONNECTIONS (TB1)
1/4” QUICK CONNECT TERMINALS
DS = DEHUMIDIFICATION SIGNAL
W2 = HEAT DEMAND FROM 2ND STAGE T/STAT
W1 = HEAT DEMAND FROM 1ST STAGE T/STAT
R = CLASS 2 VOLTAGE TO THERMOSTAT
G = MANUAL FAN FROM T'STAT
C = THERMOSTAT SIGNAL GROUND CONNECTED TO
TRANSFORMER GRD (TR) & CHASIS GROUND (GRD)
Y1 = THERMOSTAT 1ST STAGE COOL SIGNAL
Y2 = THERMOSTAT 2ND STAGE COOL SIGNAL
O = THERMOSTAT SIGNAL TO HEAT PUMP
REVERSING VALVE
L = NOT USED
DH = NOT USED
HUM = UNPOWERED NORMALLY OPEN (DRY) CONTACTS
LI = 120 VAC INPUT TO CONTROL
A
CC = 120 VAC OUTPUT TO OPTIONAL ACCESSORY
NEUTRALS = 120 VAC NEUTRAL
3/16” QUICK CONNECT TERMINALS
FLAME SENSE SIGNAL
HI COOL 24VAC
HI HEAT 24VAC
LO COOL 24VAC
LO HEAT 24VAC
PARK
PARK
COMMON 24VAC
Flame Sense
S4 DIP Switches
24VAC Indoor
Blower Terminals
HUM ACC
Ignitor and Combustion
Air Inducer
Neutrals
On Board Links
LED
Diagnostic Push
Button
FIGURE 4

Page 9
HEATING BLOWER−OFF DELAY
60 SECOND
HTG BLOWER
OFF DELAY
120 SECOND
HTG BLOWER
OFF DELAY
180 SECOND
HTG BLOWER
OFF DELAY
FLAME
15
HSI/CAI
2ND STAGE HEAT ON DELAY
7 MIN
UPSTAGE
DELAY
12 MIN
UPSTAGE
DELAY
*
W915
2 STAGE
COMPR
1−STG COMPRESSOR
2−STAGE
COMPRESSOR LINK
(JUMPERS Y1 to Y2)
W915
DO NOT CUT
2−STG COMPRESSOR
HEAT PUMP LINK
(JUMPERS R to O)
W951
(JUMPERS R to DS)
W914
W915
2 STAGE
COMPR
CUT LINK
A/C UNIT
DO NOT CUT
HEAT PUMP UNIT
CUT LINK
W951
HEAT
PUMP
W951
HEAT
PUMP
W914
DEHUM
NO SIGNATURESTAT
W/ DS CONNECTION
DO NOT CUT
SIGNATURESTAT W/
DS CONNECTION
CUT LINK
W914
DEHUM
1
1
1
ON−BOARD LINK
OPTION SELECTION
1234567
1234567
123567
4
123567
4
NEUTRALS
L1
ACC
HUM
14
36
P79
110
312
J2
4 7
W915
2 STAGE
COMPR
W951
HEAT
PUMP
W914
DEHUM
CUT FOR
OPTION
SELECTION
123456
ON
SureLight

W1W2 GY2 Y1 CC DH LODSR
W1 W2
G
Y2
Y1
C C
R
L
DH
7
−PROTECTIVE PLASTIC FILM ON DIP SWITCHES MAY BE
REMOVED FOR EASE IN SETTING OF DIP SW.
−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
1
ON
ON
ON
ON
90 SECOND
HTG BLOWER
OFF DELAY
*1234567
ON
1234567
ON
THERMOSTAT SELECTION
1−STAGE
THERMOSTAT
(TIMED STAGING)
−SEE SW #2
TWO STAGE
THERMOSTAT
*1234567
1234567
ON
ON
−BLOWER ON DELAY − 30 SEC. FIXED
1234567
ON
SENSE
IGN
CAI2
CAI1
N N
J3
S1
S4S3
* FACTORY DEFAULT
DIAGNOSTIC
LED
DIAGNOSTIC
PUSH BUTTON
INTEGRATED CONTROL CONFIGURATION GUIDE
*45 SECOND
COOL BLOWER
OFF DELAY
2 SECOND
COOL BLOWER
OFF DELAY
123567
4
123567
4
ON
ON
COOLING BLOWER-OFF DELAY
1234567
ON
1234567
ON
1234567
ON
CONTINUOUS FAN SETTINGS
LOW HEAT SPEED
LOW COOL SPEED
HIGH HEAT SPEED
HIGH COOL SPEED
DEHUMIFICATION LINK
FIGURE 5

Page 10
TABLE 3
Integrated Control Diagnostic Modes
Display Action (when button released)
No Change Remain in idle mode
Solid “E” Enter diagnostic recall mode
Solid “F” Enter ame 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).
CCooling stage (1 second ON, 0.5 second OFF)
1 or 2 displayed / Pause / Repeat codes.
d Dehumidication mode (1 second ON, 1
second OFF) / Pause / Repeat Codes).
HGas Heat Stage (1 second ON, 0.5 second
OFF) 1 or 2 displayed / Pause / Repeat codes.
Blinking during ignition.
hHeat pump stage.
Diagnostic LED (Figure 4)
The seven-segment diagnostic LED displays operating
status, error codes and other information. Table 4 lists di-
agnostic LED codes.
Diagnostic Push Button (Figure 4)
The diagnostic push button is located adjacent to the sev-
en-segment diagnostic LED. This button is used to enable
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 ve 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 ashing to conrm 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 ame signal mode.
The integrated control will display the ame current on
seven-segment LED in in micro amps (uA). Flame signal
mode is exited after any of the following:
• Power is reset
• Pressing and holding push button until 3 horizontal
• lines “≡” are displayed
• 10 minutes after entering the ame sense mode.
•