Lennox BCE3M E Series User manual

507623-02 Issue 1810 Page 1 of 22
This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in
manuals, be alert to the potential for personal injury or death.
These instructions must be read and understood completely before attempting installation.
THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER FOR FUTURE REFERENCE
Table of Contents
Unit Dimensions ..........................................................2
Shipping and Packing List ...........................................3
General........................................................................3
Requirements ..............................................................3
Installation Clearances ................................................4
Installation ...................................................................4
Condensate Drain........................................................8
Duct System and Filters ............................................10
Brazing Refrigerant Lines..........................................11
Sealing the Unit .........................................................13
Electrical Connections...............................................13
Air Flow — Cooling Blower Speed ............................17
Check-Out Procedures..............................................19
Operation...................................................................19
Maintenance..............................................................20
Cabinet Insulation......................................................20
Use of Air Handler During Construction.....................20
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional installer (or
equivalent), service agency or the gas supplier.
WARNING
Manufactured By
Allied Air Enterprises
A Lennox International, Inc. Company
215 Metropolitan Drive
West Columbia, SC 29170
*P507623-02*
(P) 507623-02
INSTALLATION INSTRUCTIONS
BCE3M*E SERIES AIR HANDLER

507623-02Issue 1810Page 2 of 22
A
CB
F
G
FRONT VIEW SIDE VIEW
LINE VOLTAGE INLETS
(Top and Right Side)
LOW VOLTAGE INLETS
(Either Side)
SUCTION
LINE
LIQUID
LINE FILTER ACCESS
CONDENSATE DRAIN
PIPING PLATE (4)
(2-1/4 x 3-3/4)
3/4 (19)
AIR FLOW
CIRCUIT
BREAKER
COVER
5 (102)
3-5/8
(92)
JH
1-1/8
(29)
1/2
(13)
D
E
LINE VOLTAGE
INLETS
(Top and Left Side)
LOW VOLTAGE
INLETS
(Top and Right Side)
1 (25)
SUPPLY AIR
OPENING
TOP VIEW
OPENING OPENING
1 (25) 1 (25)
1-1/8
(29)
1-1/8
(29)
Dimension 024 030 036 042 048/060
in. mm in. mm in. mm in. mm in. mm
A 40-1/2 1029 43 1092 48 1334 48 1219 52-1/2 1334
B 18-1/2 470 18-1/2 470 21-7/8 556 21-7/8 556 21-7/8 556
C 22 559 22 559 22 559 26-1/4 667 26-1/4 667
D 16-1/2 419 16-1/2 419 19-7/8 505 19-7/8 505 19-7/8 505
E 14-1/2 368 14-1/2 368 14-1/2 368 18-3/4 476 18-3/4 476
F 8 203 8 203 8 203 9-1/4 235 9-1/4 235
G 5-5/8 143 5-5/8 143 5-5/8 143 4-1/2 114 4-1/2 114
H 16-1/4 413 16-1/4 413 19-5/8 498 19-5/8 498 19-5/8 498
J 20-3/8 518 20-3/8 518 20-3/8 518 24-5/8 625 24-5/8 625
Note: Unit is shipped congured for horizontal left-hand air discharge. Unit may be converted to horizontal right-hand air
discharge by repositioning horizontal drain pan.
Dimensions remain the same in all congurations.
Unit Dimensions

507623-02 Issue 1810 Page 3 of 22
The Clean Air Act of 1990 bans the intentional venting
of refrigerant (CFCs, HCFCs and HFCs) as of July
1, 1992. Approved methods of recovery, recycling or
reclaiming must be followed. Fines and/or incarceration
may be levied for noncompliance.
CAUTION
NOTE: These instructions are intended as a general guide
and do not supersede national, state or local codes in any
way.
Shipping and Packing List
Package 1 of 1 contains the following:
1 - Assembled air handler unit factory-equipped for upow
or horizontal air discharge application (includes upow
and horizontal drain pans and pre-installed air lter).
Check equipment for shipping damage. If found,
immediately report damage to the last carrier. Check the
unit rating plate to conrm that delivered unit matches
order.
General
The BCE3M*E air handler is designed for indoor installation
only. As shipped, the unit is ready for installation in either
upow or horizontal left-hand air discharge applications.
Horizontal drain pan may be repositioned in the eld to
allow installation in the horizontal right-hand air discharge
position.
All units come with a metering device installed.
NOTE: These units are not approved for downow
application.
Requirements
These units are designed to match, and must be
used with, outdoor units as rated. The indoor sections
are manufactured with a metering device installed
to provide optimum refrigerant control and system
performance with a variety of different capacities of
outdoor units.
IMPORTANT
Excessive Weight Hazard - Use two or more people
when moving and installing the unit. Failure to do so
can result in back or other type of injury.
WARNING
Physical contact with metal edges and corners while
applying excessive force or rapid motion can result in
personal injury. Be aware of, and use caution when
working near these areas during installation or while
servicing this equipment.
CAUTION
These instructions are intended as a general guide and do
not supersede local or national codes in any way. Consult
authorities having jurisdiction before installation.
Compliance with all local, state, or national codes
pertaining to this type of equipment should be determined
prior to installation. Read this instruction manual, as well
as the instructions supplied in separate equipment, before
starting the installation.
In addition to conforming to manufacturer’s installation
instructions and local municipal building codes, installation
of Allied Air air handler units (with or without optional
electric heat), MUST conform with National Fire Protection
Association (NFPA) standards: “Standard for Installation of
Air Conditioning and Ventilation Systems” (NFPA No. 90A)
and “Standard for Installation of Residence Type Warm Air
Heating and Air Conditioning Systems” (NFPA No. 90B).
All models are designed for indoor installation only. The
installation of the air handler, eld wiring, duct system, etc.
must conform to the requirements of the National Electrical
Code, ANSI/NFPA No. 70 (latest edition) in the United
States, and any state laws, and local ordinances (including
plumbing or waste water codes). Local authorities having
jurisdiction should be consulted before installation is
made. Such applicable regulations or requirements take
precedence over the general instructions in this manual.
Install the conditioned air plenum, ducts and air lters
(provided) in accordance with NFPA 90B Standard for
the Installation of Warm Air Heating and Air-Conditioning
Systems (latest edition).
The air handler is shipped from the factory completely
assembled. The unit is provided with anges for the
connection of the duct system.
Do not remove the cabinet knockouts until it has been
determined which knockouts will need to be removed for
the installation.
Select the air discharge position which best suits the site
conditions. Consider required clearances, space, routing
requirements for refrigerant line, condensate disposal,
lters, duct system, wiring, and accessibility for service.
Refer to the rating plate on the air handler for specic
information.

507623-02Issue 1810Page 4 of 22
Danger of explosion. Keep ammable
materials and vapors, such as gasoline, away
from air handler. Place air handler so that
heating elements are at least 18 inches (46
cm) above the oor for a garage installation.
Failure to follow these instructions can result
in death, explosion, or re.
WARNING
Excessive condensation may occur if the unit is installed
in a warm, humid place. When the unit is installed in
an unconditioned space, apply sealant around the
electrical wires, refrigerant piping, and condensate
lines at the point where they enter the cabinet.
Apply sealant on the inside of the cabinet at the
point where the electrical wires exit through the
conduit opening. This will also keep warm and moist
unconditioned air out of the air handler cabinet where
it will form condensate on the cooler control box and
electrical controls.
IMPORTANT
This unit is approved for installation clearance to
combustible material as stated on the unit rating
plate. Accessibility and service clearances must take
precedence over combustible material clearances.
The air handler must be installed so that free access
is allowed to the coil/lter compartment and blower/
control compartment.
IMPORTANT
Horizontal applications of the air handler must be
installed sloped (approximately 5/8 inch) toward the
drain pan openings to ensure proper condensate
drainage.
IMPORTANT
Installation Clearances
Non-Ducted Return Closet Installation
The air handler can be installed in a closet with a false
bottom to form a return air plenum. It may also be installed
with a return air plenum under the air handler.
Louvers or return air grilles are eld-supplied. Local codes
may limit application of systems without a ducted return to
single-story buildings.
When a BCE3M*E unit is installed in a closet with a
louvered return opening, the minimum open area for the
louvers will be:
• 320 square inches for -024 models;
• 360 square inches for -030 and -036 models;
• 450 square inches for -042 thru -060 models.
If the free area is not known, assume a 25% free area for
wood or a 75% free area for metal louvers or grilles. Using
the louver dimensions and the 25% or 75% assumption,
determine if the open area meets the minimum open area
listed above.
If a return air plenum is used, the return air grille should be
immediately in front of the opening in the plenum to allow
for the free ow of return air. When not installed in front of
the opening, there must be adequate clearance around the
air handler to allow for the free ow of return air.
Installation
General Information
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 qualied installer or service agency.
WARNING
These units are factory-assembled and congured for
installation in upow or horizontal left-hand air discharge
applications. Horizontal drain pan may be repositioned in
the eld to allow installation in the horizontal right-hand air
discharge position.
Each unit consists of a blower assembly, refrigerant coil,
and controls in an insulated galvanized steel factory-
nished enclosure. Knockouts are provided for electrical
wiring entrance.
For ease in installation, it is best to make any necessary
coil conguration changes before setting air handler in
place.
For all performance testing, units must be tested in the
upow orientation with the horizontal drain pan removed.
Refrigerant Metering Device
These units are equipped with a factory-installed metering
device. Ensure the indoor coil metering device is properly
sized for the outdoor unit being used.

507623-02 Issue 1810 Page 5 of 22
Upow Application
1. The air handler must be supported on the bottom only
and set on solid oor or eld-supplied support frame.
Securely attach the air handler to the oor or support
frame.
2. If installing a unit in an upow application, remove the
horizontal drain pan.
IMPORTANT - The horizontal drain pan is not required
in upow air discharge installations; its removal
provides the best efciency and air ow.
3. Place the unit in the desired location and slope unit.
Connect return and supply air plenums as required
using sheet metal screws.
4. Install units that have no return air plenum on a stand
that is at least 14” from the oor. This will allow proper
air return.
Figure 1. Upow Conguration
HORIZONTAL DRAIN PAN
IMPORTANT - REMOVE PAN
FOR BEST EFFICIENCY
AND AIR FLOW.
UP-FLOW
DRAIN PAN
UP-FLOW DRAIN
CONNECTIONS (BOTH
SIDES; USE ONE SIDE
OR OTHER)
HORIZONTAL DRAIN
CONNECTIONS
(BOTH SIDES; NOT
USED)
Horizontal Applications
When removing the coil, there is possible danger of
equipment damage and personal injury. Be careful
when removing the coil assembly from a unit installed
in right- or left-hand applications. The coil may tip into
the drain pan once it is clear of the cabinet. Support the
coil when removing it.
IMPORTANT
NOTE: When the unit is installed in horizontal applications,
a secondary drain pan is recommended. Refer to local
codes.
NOTE: This unit may be installed in left-hand or right-hand
air discharge horizontal applications. Adequate support
must be provided to ensure cabinet integrity. Ensure that
there is adequate room to remove service and access
panels if installing in the horizontal position.
Left-Hand Air Discharge
1. Determine which plugs are required for drain line
connections.
2. With access door removed, remove drain line plugs to
install drain lines.
3. Set unit so that it is sloped toward the drain pan end of
the unit (see gure 11).
4. The left-hand air discharge horizontal conguration is
shown in gure 2.
Drains
AIR FLOW
PLUGS LEFT‐HAND DRAINS
Figure 2. Left-Hand Discharge Conguration
5. If the unit is suspended, the entire length of the cabinet
must be supported. If you use a chain or strap, use a
piece of angle iron or sheet metal attached to the unit
(either above or below) to support the length of the
cabinet. Use securing screws no longer than 1/2 inch
to avoid damaging the coil or lter. See gure 3. Use
sheet metal screws to connect the return and supply
air plenums as required.
FRONT VIEW
ANGLE IRON OR SHEET METAL
4 IN. (102 MM)
MAXIMUM 1/2”
LONG SCREW
AIR FLOW
ELECTRICAL INLET CLEARANCE
END VIEW
Figure 3. Suspending Horizontal Unit

507623-02Issue 1810Page 6 of 22
Right-Hand Air Discharge
For horizontal right-hand air discharge, the following eld
modications are required.
1. Remove and set aside blower and coil access panels.
2. Remove brackets securing pan to unit. See gure 4.
Figure 4
3. Remove coil assembly, bottom drain pan and
horizontal drain pan as one unit from the air handler.
See gure 5.
4. Remove the blow-off prevention brackets, top cap and
drip pan between slabs. Move the horizontal drain pan
to the opposite side of the coil. See gure 6.
NOTE: The 2-ton unit does not have or require blow-off
prevention brackets or drip pan.
Figure 5
Figure 6

507623-02 Issue 1810 Page 7 of 22
5. Reinstall the top cap. Rotate the blow-off prevention
brackets 180º and reinstall using the same screws.
Use the correct mounting holes; the brackets must
cover the hairpins. See gure 7.
Figure 7
Slide coil assembly, bottom drain pan and horizontal drain
pan as one unit back into the air handler. See gure 8.
Figure 8
6. Reinstall the brackets that hold the coil and horizontal
drain pan in place. See gure 9.
Figure 9
7. Reinstall the blower and coil access panels.

507623-02Issue 1810Page 8 of 22
Condensate Drain
The air handler is provided with ¾” NPT condensate drain connections.
On units of this type, where the blower “draws” rather than “blows” air through the coil, traps must be installed in the
condensate drain lines (primary and auxiliary, if used). Traps prevent the blower from drawing air through the drain
lines into the air supply.
IMPORTANT
ABOVE
FINISHED
SPACE?
SECONDARY (OVERFLOW) DRAIN LINE
ALWAYS RUN A SECONDARY (OVERFLOW) DRAIN LINE. IF NOT
POSSIBLE, INSTALL LOW VOLTAGE OVERFLOW SWITCH KIT.
WIRE KIT TO SHUT DOWN COMPRESSOR PER INSTRUCTIONS.
NO
YES
PART #
X3169 CLEAN OUT
VENT
PRESS IN
(DO NOT GLUE)
VENT MUST EXTEND
ABOVE HEIGHT OF
COIL DRAIN PAN BY
TWO INCHES (51MM)
1” X 3/4” X 3/4”
REDUCING
TEE WITH
PLUG
P-TRAP1 #49P66,
J-TRAP # 91P90
OR ANY PVC SCH
40 P- OR J-TRAP 3/4”
AIR HANDLER DRAIN PAN
WHEN A COIL IS LOCATED ABOVE A FINISHED
SPACE, A 3/4” (19.1MM) SECONDARY DRAIN LINE
MUST BE:
●CONNECTED TO SECONDARY DRAIN PAN
OR
●CONNECTED TO THE SECONDARY
(OVERFLOW) DRAIN OUTLET OF THE AIR
HANDLER DRAIN PAN.
TRAP MUST BE DEEP ENOUGH TO OFFSET MAXIMUM STATIC DIFFERENCES — GENERALLY,
TWO INCHES (51MM).
DRAIN LINE SHOULD
SLOPE A MINIMUM OF
ONE INCH PER 10 FEET
(25MM PER 3 METERS)
NOTE - WHEN AN AIR HANDLER IS LOCATED
ABOVE A FINISHED SPACE, THE SECONDARY
DRAIN PAN MUST HAVE A LARGER FOOTPRINT
THAN THE AIR HANDLER.
MAIN DRAIN
TO APPROVED
DRAIN
FOR NEGATIVE PRESSURE COILS (BLOWER
AFTER COIL), A TRAP IS REQUIRED ON THE
MAIN DRAIN LINE CONNECTED TO COIL.
REQUIREMENTS ON SECONDARY DRAINS.
USE TWO-PART 3/4” FEMALE SLIP INLET AND MALE ADAPTER
WHEN OBSTRUCTIONS PREVENT DIRECT THREADING OF
OVERFLOW SWITCH.
SECONDARY
DRAIN PAN
2”
(51MM)
TRAP DEPTH
1P-TRAP 49P66 REQUIRES A LARGER INSTALLATION SPACE THAN THE J-TRAP 91P90.
2PIPE NIPPLE PROVIDED IN BAG ASSEMBLY - SCH 80, 3/4” I. D. X 5” - 34K7401 (1): CUT THE PIPE
IN HALF AND USE IT TO ROUTE THE MAIN DRAIN.
SEE LOCAL CODES FOR TRAP
Figure 10. Typical Main and Overow Drain
A eld-fabricated secondary drain pan, with a drain
pipe to the outside of the building, is required in all
installations over a nished living space or in any area
that may be damaged by overow from the main drain
pan. In some localities, local codes may require a
secondary drain pan for any horizontal installation.
IMPORTANT

507623-02 Issue 1810 Page 9 of 22
Sloping the Unit
Make sure the unit is sloped (similar to the slope shown in
gure 11) (horizontal or upow) so that the drain pan will
empty completely without water standing in the pan.
THIS CORNER SHOULD BE 5/8” (+/- 1/8”) HIGHER
THAN DRAIN CORNER
DRAIN CORNER
THIS CORNER SHOULD BE
5/8” (+/- 1/8”) HIGHER THAN
DRAIN CORNER
LEVEL PLANE
LEVEL PLANE
Figure 11. Sloping the Drain
Install Condensate Drain
The air handler is equipped with ¾” NPT condensate drain
connections.
On some pans, the primary and secondary drain holes
have knockouts. Conrm primary and secondary drains
are open.
IMPORTANT
1. BCE3M*E units are equipped with a drain pan, which
includes green (main drain) and red (secondary drain)
plugs. Unscrew the plugs to remove them before
inserting condensate drain ttings. See gure 12.
DRAIN PANRED SECONDARY
DRAIN PLUG
UNSCREW PLUGS
AND CONNECT
PROPERLY SIZED
FIELD-PROVIDED
FITTINGS AND
DRAIN LINES.
GREEN MAIN
DRAIN PLUG
Figure 12
2. After removal of drain pan plugs, check the drain port
to see if holes have been drilled. If not drilled, use a
19/32” bit to drill out the primary drain hole; use a 3/8”
drill bit for the secondary drain hole. Remove all drill
shavings.
3. Install properly-sized, eld-provided connection ttings
and connect primary drain line to the main drain pan
connection.
NOTE: When installing drain line connection ttings
to the drain pan, hand tighten the tting and use a
thread sealant. Over-tightening the ttings can split
connections on the drain pan.
4. If the secondary drain line is to be used, remove the
plug or the knockout and route the drain line so that
water draining from the outlet will be easily noticed
by the homeowner. Refer to local codes for drain trap
requirements on the secondary drain line.
5. Check again to ensure drain ports and drain pan are
free of all debris.
6. Plug and check any unused drain pan openings for
tightness. Torque plugs to 30 in. lb. to prevent water
leaks or seepage from the drain pan.
7. Install a 2” trap in the main (primary) drain lines as
close to the unit as practical (see gure 10). Make sure
the top of the trap is below the connection to the drain
pan to allow complete drainage of the pan.
NOTE - Horizontal runs must have an anti-siphon air
vent (standpipe) installed ahead of the horizontal run.
See gure 10. An extremely long horizontal run may
require an oversized drain line to eliminate air traps.
NOTE - Do not operate air handler without a trap in
the main (primary) drain. The condensate drain is on
the negative pressure side of the blower; therefore, air
being pulled through the condensate line will not allow
positive drainage without a proper trap.
8. Route the drain line to the outside or to an appropriate
drain. Drain lines must be installed so they do not block
service access to the front of the air handler. A 24”
clearance is required for lter, coil, or blower removal
and service access.
NOTE - Check local codes before connecting the drain
line to an existing drainage system.
9. Insulate the drain lines where sweating could cause
water damage.
Test Condensate Drain
Test the drain pan and drain line after installation:
1. Pour several quarts of water into drain pan. Use
enough water to ll both the drain trap and the line.
2. Check the installed drain pan. Drain pan must be
draining completely. Drain line ttings must not be
leaking. Water must be draining from the end of the
primary drain line.
3. Correct any leaks found.

507623-02Issue 1810Page 10 of 22
Duct System and Filters
Duct System
The air handler is provided with anges for the connection
of the plenum and ducts. The air handler is equipped with
anges that can form a lter rack for the installation of the
air lter, or the lter may be installed as part of the return
air duct system.
Supply and return duct system must be adequately sized
to meet the system’s air requirements and static pressure
capabilities. The duct system should be insulated with
a minimum of 1” thick insulation with a vapor barrier in
conditioned areas or 2” minimum in unconditioned areas.
Supply plenum should be the same size as the anged
opening provided around the blower outlet and should
extend at least 3 ft. from the air handler before turning or
branching off plenum into duct runs. The plenum forms
an extension of the blower housing and minimizes air
expansion losses from the blower.
Filters
A lter is provided. Table 1 lists the lter size for each unit.
Table 1
Capacity Filter Size Actual Minimum
Filter Size
-024 and -030 15” x 20” x 1 14.50” x 19.50” x .75”
-036 18” x 20” x 1 17.50” x 19.50” x .75”
-042, -048 and -060 18” x 24” x 1 17.50” x 23.50” x .75”
If a high -efciency lter is being installed as part of
this system to ensure better indoor air quality, the lter
must be properly sized. High -efciency lters have a
higher static pressure drop than standard- efciency
glass/foam lters. If the pressure drop is too great,
system capacity and performance may be reduced.
The pressure drop may also cause the limit to trip
more frequently during the winter and the indoor coil
to freeze in the summer, resulting in an increase in the
number of service calls.
Before using any lter with this system, check the
specications provided by the lter manufacturer
against the data given in the appropriate Allied Air
Product Specications bulletin.
IMPORTANT
Installing Duct System
Install the conditioned air plenum, ducts and air lters
(not provided) in accordance with NFPA 90B Standard for
the Installation of Warm Air Heating and Air-Conditioning
Systems (latest edition).
Connect supply air duct to the ange on top of the air
handler. If an isolation connector is used, it must be
nonammable.
Field-Fabricated Return Air Duct Flange for
Horizontal Applications
A return air duct system is recommended, but not factory-
provided. If the unit is installed in a conned space or
closet, run a full-size return connection to a location outside
the closet.
Figure 13. Cabinet and Duct Flange
BOTTOM OF
CABINET
DUCT
ADAPTER
1−1/2
(38)
“A”
BRAKE DOWN 90 DEGREES
1/4 (6) DIA.
2−HOLES
“A”
−024 & −030 18−3/8 (467)
−036 to −060 21−3/4 (552)
1−1/2(38)
3/4
(19)
3/4
(19)
1−1/2
(38)
3/4
(19)
1/2
(13)
3/4
(19)
DUCT
FLANGE
CABINET
DOOR FLANGE
UNIT SIZE