Lennox Merit CBA25UHE User manual

©2023 Lennox Industries Inc.
Dallas, Texas, USA
Page 1
THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER FOR FUTURE REFERENCE
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer or
equivalent, service agency, or the gas supplier.
IMPORTANT
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.
WARNING
To prevent serious injury or death:
1. Lock-out/tag-out before performing maintenance.
2. If system power is required (e.g., smoke detector
maintenance), disable power to blower, remove fan
belt where applicable, and ensure all controllers
and thermostats are set to the “OFF” position before
performing maintenance.
3. Always keep hands, hair, clothing, jewelry, tools, etc.
away from moving parts.
INSTALLATION
INSTRUCTIONS
MULTI-POSITION AIR HANDLERS
508370-01
6/2023
Merit®Series
CBA25UHE Air Handler Units
Shipping and Packing List
Package 1 of 1 contains:
1 – Assembled air handler unit factory-equipped for upow
or horizontal air discharge application (includes upow
and horizontal drain pans and preinstalled air lter).
Check the air handler for shipping damage; if found, im-
mediately contact the last carrier. Check the unit rating
plate to conrm that delivered unit matches order.
IMPORTANT: Special procedures are required for clean-
ing the all-aluminum coil in this unit. See page 19 in this
instruction for information.
Table of Contents
Unit Dimensions – Upow Position.................................2
Unit Dimensions – Horizontal Position ..........................3
General Information .......................................................4
Requirements ................................................................4
Installation Clearances ..................................................5
Installation .....................................................................5
Condensate Drain...........................................................8
Duct System and Filters ...............................................9
Brazing Refrigerant Lines ............................................10
Sealing the Unit ...........................................................13
Electrical Connections .................................................13
Air Flow – Cooling Blower Speed ................................16
Blower Data ................................................................17
Check-out Procedures .................................................18
Operation ....................................................................18
Homeowner Maintenance ............................................19
Repairing or Replacing Cabinet Insulation ..................19
Professional Maintenance ...........................................19
Use of Air Handler During Construction .......................19

Page 2
Unit Dimensions – Upow Position
A
B
FRONT VIEW SIDE VIEW
LINE VOLTAGE
INLETS
(Top and Right Side)
LOW VOLTAGE
INLETS
(Either Side)
SUCTION
LINE
LIQUID
LINE
FILTER
ACCESS
3/4
(19)
AIR FLOW
CIRCUIT
BREAKER
COVER
D
1-1/8
(29)
1/2
(13)
C
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)
20-3/8
(518)
22
(559)
14-1/2
(368)
DETAIL OF PIPING PLATE
LIQUID
LINE CONDENSATE
DRAINS (2)
(Horizontal)
1-3/4
(44)
3/4 (19)
2-3/4
(70)
3-1/2
(89)
PIPING
PLATE
4-3/4
(121)
4-3/8
(111)
2-3/8
(60)
CONDENSATE
DRAINS (2)
(Upflow and
Downflow)
SUCTION
LINE
CONDENSATE DRAIN
PIPING PLATE (3)
(2-1/4 x 3-3/4)
Dimensions 024 030036, 042
in. mm in. mm in.mm
A45-1/2 1156 47 1194 53-5/8 1362
B18-1/2 470 18-1/2 47021-1/2546
C16-1/2 419 16-1/2 41919-1/2495
D16-1/4 413 16-1/4 41319-1/4489

Page 3
Unit Dimensions – Horizontal Position
A
B
FRONT VIEWEND VIEW
LINE VOLTAGE INLETS
(Top and Right Side)
LOW VOLTAGE INLETS
(Either Side)
SUCTION
LINE
LIQUID
LINE
FILTER
ACCESS
CONDENSATE DRAIN
PIPING PLATE (3)
(2-1/4 x 3-3/4)
3/4
(19)
AIR FLOW
CIRCUIT
BREAKER
COVER
D
1-1/8
(29)
1/2
(13)
C
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)
20-3/8
(518)
22
(559)
14-1/2
(368)
DETAIL OF PIPING PLATE
LIQUID
LINE
CONDENSATE
DRAINS (2)
(Horizontal)
1-3/4
(44)
3/4
(19)
2-3/4
(70)
3-1/2
(89)
4-3/4
(121)
4-3/8
(111)
2-3/8
(60)
CONDENSATE
DRAINS (2)
(Upflow and
Downflow)
SUCTION
LINE
PIPING
PLATE
Dimensions 024 030036, 042
in. mm in.mmin. mm
A45-1/2 1156 47 1194 53-5/8 1362
B18-1/2 470 18-1/2 47021-1/2546
C16-1/2 419 16-1/2 41919-1/2495
D16-1/4 413 16-1/4 41319-1/4489

Page 4
General Information
The CBA25UHE series air handler with all-aluminum
coil is designed for indoor installation in conditioned or
unconditioned spaces. As shipped, the unit is ready for
installation in either upow, horizontal left-hand or right-
hand air discharge applications. Electric heat, downow
air discharge kits, air lters and other accessories are
available and listed in the CBA25UHE Product Specica-
tion bulletin for ordering.
This instruction is intended as a general guide and does
not supersede local or national codes in any way. Consult
authorities having jurisdiction before installation.
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.
Requirements
WARNING
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.
IMPORTANT
CBA25UHE units include a factory-installed check/
expansion valve which will provide optimal refrigerant
control and system performance with outdoor units of
varying capacities. These units must be installed as a
part of a matched system as outlined in the CBA25UHE
Product Specication bulletin.
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 pertain-
ing 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 start-
ing the installation.
In addition to conforming to manufacturer’s installation in-
structions and local municipal building codes, installation
of Lennox air handler units (with or without optional elec-
tric heat), MUST conform with National Fire Protection As-
sociation (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 Electri-
cal Code, ANSI/NFPA No. 70 (latest edition) in the United
States, and any state laws, and local ordinances (includ-
ing 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 instruc-
tions 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 Sys-
tems (latest edition).
The air handler is shipped from the factory completely as-
sembled. The unit is provided with anges for the connec-
tion of the duct system.
Do not remove the cabinet knockouts until it has been de-
termined 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 in-
formation.
WARNING
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.
IMPORTANT
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 electrical
wires, refrigerant piping and condensate lines at the
point where they enter the cabinet.
This will help prevent air leakage into, and condensation
from forming inside of, the air handler, the control box,
and on the 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.

Page 5
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 CBA25UHE unit is installed in a closet with a lou-
vered return opening, the minimum open area for the lou-
vers will be:
• 320 square inches for -024 models;
• 360 square inches for -030 and -036 models;
• 450 square inches for -042 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
Each unit consists of a blower assembly, refrigerant coil,
and controls in an insulated galvanized steel factory-n-
ished enclosure. Knockouts are provided for electrical wir-
ing entrance.
For ease in installation, it is best to make any necessary
coil conguration changes before setting air handler in
place.
REFRIGERANT METERING DEVICE
CBA25UHE units are equipped with a factory-installed
check/ expansion valve.
UPFLOW 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 e󰀩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.
HORIZONTAL DRAIN PAN
(MUST BE REMOVED)
UP-FLOW /
DOWN-FLOW
DRAIN PAN
FIGURE 1. Upow Conguration
HORIZONTAL APPLICATIONS
IMPORTANT
When removing the coil, there is a possibility of 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..
NOTE - When the unit is installed in horizontal applica-
tions, 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 sup-
port 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.

Page 6
RIGHT-HAND 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 upow drain
pan end of the unit and level from front to back of
unit (see gure 7).
4 - The horizontal conguration is shown in gure 2.
Drains
AIR FLOW
PLUGS
RIGHT‐HAND DRAINS
FIGURE 2. Right-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 WEIVDNEWEIV
ANGLE IRON OR SHEET
METAL
E
ANCE 4 IN. (102 MM)
MAXIMUM 1/2"
LONG SCREW
AIR FLOW
FIGURE 3. Suspending Horizontal Unit
LEFT-HAND AIR DISCHARGE
For horizontal left-hand air discharge, the following eld
modications are required. Reference sticker on coil top
plate.
1 - Remove access panels and the corrugated padding
between the blower and coil assembly. Discard the
corrugated padding.
2 - Pull the coil assembly from unit. Pull o󰀨 the
horizontal drain pan.
3 - Remove the drain plugs from back drain holes on
horizontal drain pan and reinstall them on front holes.
IMPORTANT
After removal of drain pan plug(s), check drain hole(s)
to verify that drain opening is fully open and free of any
debris. Also check to make sure that no debris has fallen
into the drain pan during installation that may plug up the
drain opening.
4 - Rotate drain pan 180º front-to-back and install it on
the opposite side of the coil.
5 - Remove screws from top cap.
6 - Remove plastic plug from left hole on coil front end
seal and reinstall plug in back hole.
90º
BEND
CABINET
SUPPORT
COIL SHOWN IN UPLOAD POSITION FOR EASY CONVERSION
TOP CAP SCREWS
DRAIN PAN
RE
INSTALLED
HERE
DRAIN PAN
SHIPPING
LOCATION
TOP CAP ROTATED TO
CORRECT POSITION
———— DRAIN PLUGS ————
REINSTALLED HERE REMOVED FROM HERE
BACK COIL END SEAL
TOP
CAP
90º
BEND
ALIGN HOLES WITH
HOLES IN COIL END
PLATE. STARTING WITH
THE ROUND HOLES ON
THIS END.
FIGURE 4. Field Modication for
Left-Hand Discharge
7 - Rotate top cap 180º front-to-back and align with
unused screw holes. Holes must align with front
and back coil end plates. The top cap has a 45º
bend on one side and a 90º bend on the other.
The 90º bend must be on the same side as the
horizontal drain pan as illustrated in gure 4.

Page 7
FIGURE 5. Left-Hand Discharge Conguration
NOTE – Be very careful when reinstalling the screws into
the coil end plate engaging holes. Misaligned screws may
damage the coil.
8 - From the upow position, ip cabinet 90º to the
left and set into place. Replace blower assembly.
Secure coil in place by bending down the tab on the
cabinet support rail as illustrated.
9 - Knock out drain seal plate from access door. Secure
plate to cabinet front ange with screw provided.
10 - Flip access door and replace it on the unit.
11 - Set unit so that it is sloped 1/4ʺ toward the drain
pan end of the unit. Connect return and supply air
plenums as required using sheet metal screws.
12 - If suspending the unit, it must be supported along the
entire length of the cabinet. If using chain or strap,
use a piece of angle iron or sheet metal attached
to the unit (either above or below) so that the full
length of the cabinet is supported. Use securing
screws no longer than 1/2ʺ to avoid damage to coil
or lter, as illustrated in gure 3. Connect return and
supply air plenums as required using sheet metal
screws.
DOWNFLOW APPLICATION
NOTE – If downow application is required, separately or-
der kit number Y9658 (-024 through -030) or Y9659 (-036
through -042) and install per kit’s instructions. Also use
metal or class I supply and return air plenums.
Use the installation instruction provided with the downow
kit.
IMPORTANT
If electric heat section with circuit breakers (ECBA25) is
installed in a CBA25UHE unit in a downow application,
the circuit breakers must be rotated 180° to the UP
position. See ECBA25 installation instructions for more
details.

Page 8
Condensate Drain
IMPORTANT
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.
ABOVE
FINISHED
SPACE?
OVERFLOW DRAIN LINE
ALWAYS RUN AN OVERFLOW DRAIN LINE. IF NOT POSSIBLE TO
ROUTE OVERFLOW DRAIN LINE, INSTALL LOW VOLTAGE
OVERFLOW SWITCH KIT. WIRE KIT TO SHUT DOWN
COMPRESSOR PER INSTRUCTIONS.
NO
YES
LENNOX #
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
LENNOX1P-TRAP
49P66, J-TRAP #
91P90 OR ANY
PVC SCH 40 P- OR
J-TRAP 3/4”
OVERFLOW
DRAIN
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 OVERFLOW DRAIN OUTLET OF
THE AIR HANDLER DRAIN PAN.
TRAPS 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 A 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) TRAPS ARE REQUIRED ON ALL
DRAIN LINES CONNECTED TO COIL.
COMPACT OVERFLOW SWITCH WITH 3/4” FEMALE SLIP INLET
AND MALE ADAPTER, TWO PART DESIGN FOR USE WHERE
OBSTRUCTIONS PREVENT DIRECT THREADING
SECONDARY
DRAIN PAN
2”
(51MM)
TRAP DEPTH
1LENNOX P-TRAP 49P66 REQUIRES A LARGER INSTALLATION SPACE THAN THE J-TRAP 91P90.
FIGURE 6. Typical Main and Overow Drain
IMPORTANT
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.
SLOPING THE UNIT
Make sure the unit is sloped (similar to the slope shown in
gure 7) so that the drain pan will empty completely with-
out water standing in the pan.
THIS CORNER SHOULD BE 5/8" (+/- 1/8") HIGHER
THAN DRAIN CORNER
DRAIN CORNER
LEVEL PLANE
FIGURE 7. Sloping the Unit for Proper Drainage

Page 9
NOTE - Check local codes before connecting the drain
line to an existing drainage system. 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.
Duct System and Filters
DUCT SYSTEM
The air handler is provided with anges for the connection
of the supply plenum.
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 con-
ditioned 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 ex-
tend at least 3 ft. from the air handler before turning or
branching o󰀨 plenum into duct runs. The plenum forms an
extension of the blower housing and minimizes air expan-
sion losses from the blower.
FILTERS
A lter is provided. Table 1 lists the lter size for each unit.
TABLE 1. Unit Air Filter Size Chart
CBA25UHE Filter Size – In.
-024, -030 15" x 20" x 1"
-036, -042 18" x 20" x 1"
IMPORTANT
If a high e󰀩ciency lter is being installed as part of this
system to ensure better indoor air quality, the lter must
be properly sized. High e󰀩ciency lters have a higher
static pressure drop than standard e󰀩ciency glass/foam
lters. If the pressure drop is too great, system capacity
and performance may be reduced. Before using any
lter with this system, check the specications provided
by the lter manufacturer against the data given in the
appropriate Lennox Product Specications bulletin.
Additional information is provided in Service and
Application Note ACC002 (August 2000)..
INSTALL CONDENSATE DRAIN
The air handler is provided with 3/4" NPT condensate
drain connections.
IMPORTANT
Conrm primary and secondary drains are open.
1 - CBA25UHE 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.
DRAIN PAN
ALL CBA25UHE MODELS
RED SECONDARY
DRAIN PLUG
UNSCREW PLUGS
AND CONNECT
PROPERLY SIZED
FIELD-PROVIDED
FITTINGS AND
DRAIN LINES.
GREEN MAIN
DRAIN PLUG
FIGURE 8. Drain Line Connections
2 - 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.
3 - 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.
4 - Check again to ensure drain ports and drain pan
are free of all debris.
5 - 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.
6 - Install a 2" trap in the main (primary) drain lines as
close to the unit as practical (see gure 6). 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 g-
ure 6. 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.
7 - 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.

Page 10
INSTALLING DUCT SYSTEM
Connect supply air duct to the ange on top of the air han-
dler. If an isolation connector is used, it must be nonam-
mable.
FIELD-FABRICATED RETURN AIR DUCT FLANGE
FOR HORIZONTAL APPLICATIONS
A return air duct system is recommended, but not facto-
ry-provided. If the unit is installed in a conned space or
closet, run a full-size return connection to a location out-
side the closet.
BOTTOM OF
CABINET
DUCT
ADAPTER
1−1/2
(38)
”A”
BRAKE DOWN 90 DEGREES
1/4 (6) DIA.
2−HOLES
"A"
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
Cabinet and Duct Flange
-024, -030
-036, -042
18-3/8"
21-1/2"
FIGURE 9. Cabinet and Duct Flange
Brazing Refrigerant Lines
Refrigerant lines must be connected by a qualied techni-
cian in accordance with established procedures.
IMPORTANT
Refrigerant lines must be clean, dry, refrigerant-grade
copper lines. Air handler coils should be installed
only with specied line sizes for approved system
combinations.
Handle the refrigerant lines gently during the installation
process. Sharp bends or kinks in the lines will cause a
restriction.
Do not remove the caps from the lines or system
connection points until connections are ready to be
completed.
WARNING
Polyol ester (POE) oils used with HFC-410A refrigerant
absorb moisture very quickly. It is very important that the
refrigerant system be kept closed as much as possible.
DO NOT remove line set caps or service valve stub caps
until you are ready to make connections.
WARNING
Danger of re. Bleeding the refrigerant
charge from only the high side may result
in pressurization of the low side shell and
suction tubing. Application of a brazing torch
to a pressurized system may result in ignition
of the refrigerant and oil mixture. Check the
high and low pressures before applying heat.
WARNING
When using a high pressure gas such as
nitrogen to pressurize a refrigeration or air
conditioning system, use a regulator that can
control the pressure down to 1 or 2 psig (6.9
to 13.8 kPa).
CAUTION
Brazing alloys and ux contain materials which are
hazardous to your health.
Avoid breathing vapors or fumes from brazing operations.
Perform operations only in well-ventilated areas.
Wear gloves and protective goggles or face shield to
protect against burns.
Wash hands with soap and water after handling brazing
alloys and ux.
IMPORTANT
To prevent the build-up of high levels of nitrogen when
purging, it must be done in a well-ventilated area. Purge
low-pressure nitrogen (1 to 2 psig) through the refrigerant
piping during brazing. This will help to prevent oxidation
and the introduction of moisture into the system.