Lennox 14HPX Installation and operation manual

Page 1 ©2007 Lennox Industries Inc.
Corp. 0719−L5 14HPX
Service Literature 1.5 to 5 ton
Revised 06−2008
14HPX SERIES UNITS
The 14HPX is a residential split-system heat pump. The
series is designed for use with expansion valves (TXV) and
HFC−410A refrigerant. All 14HPX units utilize scroll compres-
sors.
14HPX series units are available in 1−1/2, 2, 2 -1/2, 3, 3
-1/2, 4 and 5 ton capacities. All major components (indoor
blower and coil) must be matched according to Lennox rec-
ommendations for the compressor to be covered under
warranty. Refer to the Engineering Handbook for approved
system matchups.
This manual is divided into sections which discuss the
major components, refrigerant system, charging proce-
dure, maintenance and operation sequence.
Information contained in this manual is intended for use by
qualified service technicians only. All specifications are subject
to change.
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect electronic
components. Take precautions during unit instal-
lation and service to protect the unit’s electronic
controls. Precautions will help to avoid control
exposure to electrostatic discharge by putting
the unit, the control and the technician at the
same electrostatic potential. Neutralize electro-
static charge by touching hand and all tools on an
unpainted unit surface before performing any
service procedure.
WARNING
Refrigerant can be harmful if it is inhaled. Refrigerant
must be used and recovered responsibly.
Failure to follow this warning may result in person-
al injury or death.
CAUTION
In order to avoid injury, take proper precaution when
lifting heavy objects.
Table of Contents
Specifications / Electrical Data Page 2. . . . . . . . .
I Unit Components Page 4. . . . . . . . . . . . . . . . . . .
II Refrigerant System Page 14. . . . . . . . . . . . . . . . .
III Charging Page 17. . . . . . . . . . . . . . . . . . . . . . . . .
IV Maintenance Page 22. . . . . . . . . . . . . . . . . . . . . .
V Diagrams Page 23. . . . . . . . . . . . . . . . . . . . . . . . .

Page 2
SPECIFICATIONS
General
Dt
Model No. 14HPX−018 14HPX−024 14HPX−030 614HPX−036
Data Nominal Tonnage 1.5 2 2.5 3
1Sound Rating Number 76 76 76 79
Connections
(t)
Liquid line o.d. − in. 3/8 3/8 3/8 3/8
(sweat) Vapor line o.d. − in. 3/4 3/4 3/4 7/8
2Refrigerant HFC−410A charge furnished 8 lbs. 4 oz. 8 lbs. 0 oz. 7 lbs. 2 oz. 9 lbs. 12 oz.
Outdoor
Cil
Net face area
ft
Outer coil 13.30 13.30 15.21 19.39
Coil sq. ft. Inner coil 12.60 12.60 14.50 18.77
Tube diameter − in. 5/16 5/16 5/16 5/16
No. of rows 2 2 2 2
Fins per inch 22 22 22 22
Outdoor
F
Diameter − in. 18 18 18 26
Fan No. of Blades 3 3 3 4
Motor hp 1/10 1/10 1/10 1/3
Cfm 2165 2165 2232 4090
Rpm 1015 1015 1035 844
Watts 171 171 165 299
Shipping Data − lbs. 1 package 156 156 166 212
ELECTRICAL DATA
Line voltage data − 60 hz − 1ph 208/230V 208/230V 208/230V 208/230V
3Maximum overcurrent protection (amps) 20 30 30 30
4Minimum circuit ampacity 11.9 17.5 17.0 19.4
Compressor Rated Load Amps 8.97 13.46 13.1 14.1
p
Locked Rotor Amps 48 58 64 77
Power Factor 0.96 0.97 0.98 0.98
Outdoor
FMt
Full Load Amps 0.70 0.70 0.70 1.8
Fan Motor Locked Rotor Amps 1.4 1.4 1.4 2.9
OPTIONAL ACCESSORIES − must be ordered extra
Compressor Crankcase Heater 93M04 SS S
p
Factory S
Compressor Hard Start Kit 10J42 S S S S
Compressor Low Ambient Cut−Off 45F08 S S S S
Compressor Sound Cover 69J03 S S S S
Freezestat 3/8 in. tubing 93G35 S S S S
5/8 in. tubing 50A93 S S S S
Hail Guards 92M89 S S
92M88 S
27W34 S
Indoor Blower Off Delay Relay 58M81 S S S S
Loss of Charge Kit 84M23 S S S S
5Low Ambient Kit 54M89 S S S S
Mild Weather Kit 33M07 S S S S
Monitor Kit − Service Light 76F53 S S S S
Mounting Base 69J06 SSS
g
69J07 S
Outdoor
Th t t Kit
Thermostat 56A87 S S S S
Thermostat Kit Mounting Box 31461 SS S S
Refrigerant
Line Sets
L15−41−20
L15−41−30
L15−41−40
L15−41−50
SSS
e Sets
L15−65−30 L15−65−40
L15−65−50
S
Unit Stand−Off Kit 94J45 S S S S
NOTE − Extremes of operating range are plus 10% and minus 5% of line voltage.
1Sound Rating Number rated in accordance with test conditions included in ARI Standard 270.
2Refrigerant charge sufficient for 15 ft. length of refrigerant lines.
3HACR type circuit breaker or fuse.
4Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.
5Crankcase Heater and Freezestat are recommended with Low Ambient Kit.
614HPX−036 not available in Canada.

Page 3
SPECIFICATIONS
General
Dt
Model No. 14HPX−042 14HPX−048 14HPX−060
Data Nominal Tonnage 3.5 4 5
1Sound Rating Number 79 80 80
Connections
(t)
Liquid line o.d. − in. 3/8 3/8 3/8
(sweat) Vapor line o.d. − in. 7/8 7/8 1-1/8
2Refrigerant HFC−410A charge furnished 12 lbs. 7 oz. 12 lbs. 10 oz. 16 lbs. 0 oz.
Outdoor
Cil
Net face area
ft
Outer coil 24.93 24.93 29.09
Coil sq. ft. Inner coil 24.13 24.13 28.16
Tube diameter − in. 5/16 5/16 5/16
No. of rows 2 2 2
Fins per inch 22 22 22
Outdoor
F
Diameter − in. 26 26 26
Fan No. of Blades 4 4 4
Motor hp 1/3 1/3 1/3
Cfm 4347 4347 4550
Rpm 843 843 830
Watts 299 299 307
Shipping Data − lbs. 1 package 257 262 307
ELECTRICAL DATA
Line voltage data − 60 hz − 1ph 208/230V 208/230V 208/230V
3Maximum overcurrent protection (amps) 40 50 60
4Minimum circuit ampacity 24.2 29 34.8
Compressor Rated Load Amps 17.94 21.79 26.41
p
Locked Rotor Amps 112 117 134
Power Factor 0.94 0.95 0.98
Outdoor
FMt
Full Load Amps 1.8 1.8 1.8
Fan Motor Locked Rotor Amps 2.9 2.9 2.9
OPTIONAL ACCESSORIES − must be ordered extra
Compressor Crankcase Heater Factory SS S
Compressor Hard Start Kit 10J42 S S
p
81J69 S
Compressor Low Ambient Cut−Off 45F08 S S S
Compressor Sound Cover 69J03 S S S
Freezestat 3/8 in. tubing 93G35 S S S
5/8 in. tubing 50A93 S S S
Hail Guards 27W36 S S
94M94 S
Indoor Blower Off Delay Relay 58M81 S S S
Loss of Charge Kit 84M23 S S S
5Low Ambient Kit 54M89 S S S
Mild Weather Kit 33M07 S S S
Monitor Kit − Service Light 76F53 S S S
Mounting Base 69J07 S S S
Outdoor
Th t t Kit
Thermostat 56A87 S S S
Thermostat Kit Mounting Box 31461 SS S
Refrigerant
Line Sets
L15−65−30 L15−65−40
L15−65−50
S S
e Sets
Field Fabricate S
Unit Stand−Off Kit 94J45 S S S
NOTE − Extremes of operating range are plus 10% and minus 5% of line voltage.
1Sound Rating Number rated in accordance with test conditions included in ARI Standard 270.
2Refrigerant charge sufficient for 15 ft. length of refrigerant lines.
3HACR type circuit breaker or fuse.
4Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.
5Crankcase Heater and Freezestat are recommended with Low Ambient Kit.

Page 4
I − UNIT COMPONENTS
Unit components are illustrated in figure 1.
14HPX UNIT COMPONENTS
FIGURE 1
service valves
compressor
reversing valve
condenser fan
drier
muffler
high pressure switch
(on liquid line, hidden)
txv valve
FIGURE 2
DUAL CAPACITOR
(C12)
COMPRESSOR
CONTACTOR
(K1)
14HPX UNIT CONTROL BOX
GROUNDING
LUG DEFROST
CONTROL
(CMC1)
A − Control Box (Figure 2)
14HPX units are not equipped with a 24V transformer. All
24 VAC controls are powered by the indoor unit. Refer to
wiring diagram.
Electrical openings are provided under the control box cov-
er. Field thermostat wiring is made to a 24V terminal strip
located on the defrost control board located in the control
box. See figure 3.
24V THERMOSTAT TERMINAL STRIP
FIGURE 3
W1 C L R O Y1*Y2
*not used
1 − Compressor Contactor (K1)
The compressor is energized by a contactor located in the
control box. See figure 2. Single−pole contactors are used
in 14HPX series units. See wiring diagrams for specific
unit. K1 is energized through the CMC1 board by the in-
door thermostat terminal Y1 (24V) when thermostat de-
mand is present.
DANGER
Electric Shock Hazard.
May cause injury or death.
Disconnect all remote electrical power
supplies before opening unit panel. Unit
may have multiple power supplies.
Some units are equipped with single−
pole contactors. When unit is equipped
with a single−pole contactor, line voltage
is present at all components (even when
unit is not in operation).
2 − Dual Capacitor (C12)
The compressor and fan in 14HPX series units use permanent
split capacitor motors. The capacitor is located inside the unit
control box (see figure 2). A single dual" capacitor (C12) is
used for both the fan motor and the compressor (see unit wir-
ing diagram). The fan side and the compressor side of the ca-
pacitor have different MFD ratings.

Page 5
3 − Defrost System (CMC1)
The demand defrost control measures differential tem-
peratures to detect when the system is performing poorly
because of ice build−up on the outdoor coil. The controller
self−calibrates" when the defrost system starts and after
each system defrost cycle. The defrost control board com-
ponents are shown in figure 4.
The control monitors ambient temperature, outdoor coil
temperature, and total run time to determine when a de-
frost cycle is required. The coil temperature probe is de-
signed with a spring clip to allow mounting to the outside
coil tubing. The location of the coil sensor is important for
proper defrost operation.
NOTE − The demand defrost board accurately measures
the performance of the system as frost accumulates on the
outdoor coil. This typically will translate into longer running
time between defrost cycles as more frost accumulates on
the outdoor coil before the board initiates defrost cycles.
Diagnostic LEDs
The state (Off, On, Flashing) of two LEDs on the defrost
board (DS1 [Red] and DS2 [Green]) indicate diagnostics
conditions that are described in table 2.
24V TERMINAL
STRIP
CONNECTIONS
DIAGNOSTIC
LEDS
PRESSURE
SWITCH CIRCUIT
CONNECTIONS
TEST PINS
NOTE − Component Locations Vary by Board Manufacturer.
Y2 not used on 14HPX
SENSOR
PLUG IN
(COIL & AM-
BIENT
SENSORS)
REVERSING
VALVE
DELAY
PINS
LOW
AMBIENT
THERMOSTAT
PINS
DEFROST
TERMINATION
PIN SETTINGS
FIGURE 4
Defrost Control Pressure Switch Connections
The unit’s automatic reset pressure switches (LO PS − S87
and HI PS − S4) are factory−wired into the defrost board on
the LO−PS and HI−PS terminals, respectively.
(OPTIONAL) Low Pressure Switch (LO−PS)When the
low pressure switch trips, the defrost board will cycle off the
compressor, and the strike counter in the board will count
one strike. The low pressure switch is ignored under the fol-
lowing conditions:
Sduring the defrost cycle and 90 seconds after the ter-
mination of defrost
Swhen the average ambient sensor temperature is be-
low 15° F (−9°C)
Sfor 90 seconds following the start up of the compressor
Sduring "test" mode
High Pressure Switch (HI−PS)When the high pressure
switch trips, the defrost control will cycle off the compres-
sor, and the strike counter in the control will count one
strike.
Defrost Control Pressure Switch Settings
High Pressure (auto reset) − trip at 590 psig; reset at 418.
Low Pressure (auto reset) − trip at 25 psig; reset at 40 psig.
5−Strike Lockout Feature
The internal control logic of the control counts the pressure
switch trips only while the Y1 (Input) line is active. If a pres-
sure switch opens and closes four times during a Y1 (In-
put), the control logic will reset the pressure switch trip
counter to zero at the end of the Y1 (Input). If the pressure
switch opens for a fifth time during the current Y1 (Input),
the control will enter a lockout condition.
The 5−strike pressure switch lockout condition can be reset
by cycling OFF the 24−volt power to the control board or by
shorting the TEST pins between 1 and 2 seconds. All timer
functions (run times) will also be reset.
If a pressure switch opens while the Y1 Out line is engaged,
a 5−minute short cycle will occur after the switch closes.
Defrost System Sensors
Sensors connect to the defrost control through a field-re-
placeable harness assembly that plugs into the board.
Through the sensors, the control detects outdoor ambient
and coil temperature fault conditions. As the detected tem-
perature changes, the resistance across the sensor
changes. Figure 5 shows how the resistance varies as the
temperature changes for both type of sensors. Sensor re-
sistance values can be checked by ohming across pins
shown in table 1.
TABLE 1
Sensor
Temperature
Range °F (°C)
Resistance values
range (ohms)
Pins/Wire
Color
Outdoor
(Ambient)
−35 (−37) to 120
(48)
280,000 to 3750 3 & 4
(Black)
Coil −35 (−37) to 120
(48)
280,000 to 3750 5 & 6
(Brown)
Discharge (if
applicable)
24 (−4) to 350
(176)
41,000 to 103 1 & 2
(Yellow)
Note: Sensor resistance decreases as sensed temperature increases
(see figure5).
NOTE − When checking the ohms across a sensor, be
aware that a sensor showing a resistance value that is not
within the range shown in table 1, may be performing as de-
signed. However, if a shorted or open circuit is detected,
then the sensor may be faulty and the sensor harness will
needs to be replaced.
Coil SensorThe coil temperature sensor (shown in fig-
ure 6) considers outdoor temperatures below −35°F
(−37°C) or above 120°F (48°C) as a fault. If the coil temper-
ature sensor is detected as being open, shorted or out of
the temperature range of the sensor, the board will not per-
form demand or time/temperature defrost operation and
will display the appropriate fault code. Heating and cooling
operation will be allowed in this fault condition.

Page 6
Ambient and Coil Sensor
RESISTANCE (OHMS)
TEMPERATURE (ºF)
5750
7450
9275
11775
15425
19975
26200
34375
46275
62700
100
90
80
70
60
50
40
30
20
10
0
10000 30000 50000 70000 90000
85300
FIGURE 5
COIL SENSOR −
Clip coil temperature sensor from the de-
frost board on the bend shown − 6th bend
up. Apply grease between bend and sen-
sor.
AMBIENT
SENSOR
FIGURE 6
Ambient SensorThe ambient sensor (shown in figure 6)
considers outdoor temperatures below −35°F (−37°C) or
above 120°F (48°C) as a fault. If the ambient sensor is de-
tected as being open, shorted or out of the temperature
range of the sensor, the control will not perform demand
defrost operation. The control will revert to time/tempera-
ture defrost operation and will display the appropriate fault
code. Heating and cooling operation will be allowed in this
fault condition.
NOTE − Within a single room thermostat demand, if
5−strikes occur, the board will lockout the unit. Defrost
board 24 volt power R" must be cycled OFF" or the
TEST" pins on board must be shorted between 1 to 2 sec-
onds to reset the board.
Defrost Temperature Termination Shunt (Jumper)
PinsThe defrost control selections are: 50, 70, 90, and
100°F (10, 21, 32 and 38°C). The shunt termination pin is
factory set at 50°F (10°C). If the temperature shunt is not
installed, the default termination temperature is 90°F
(32°C).
Delay Mode
The defrost control has a field−selectable function to re-
duce occasional sounds that may occur while the unit is
cycling in and out of the defrost mode. When a jumper is
installed on the DELAY pins, the compressor will be cycled
off for 30 seconds going in and out of the defrost mode.
Units are shipped with jumper installed on DELAY pins.

Page 7
NOTE − The 30 second off cycle is NOT functional when
jumpering the TEST pins.
Operational Description
The defrost control has three basic operational modes:
normal, calibration, and defrost.
Normal ModeThe demand defrost control monitors the
O line, to determine the system operating mode (heat/
cool), outdoor ambient temperature, coil temperature (out-
door coil) and compressor run time to determine when a
defrost cycle is required.
Calibration ModeThe control is considered uncali-
brated when power is applied to the control, after cool
mode operation, or if the coil temperature exceeds the ter-
mination temperature when it is in heat mode.
Calibration of the control occurs after a defrost cycle to en-
sure that there is no ice on the coil. During calibration, the
temperature of both the coil and the ambient sensor are
measured to establish the temperature differential which is
required to allow a defrost cycle. See figure 8 for calibration
mode sequence.
Defrost ModeThe following paragraphs provide a de-
tailed description of the defrost system operation.
Detailed Defrost System Operation
Defrost CyclesThe demand defrost control initiates a
defrost cycle based on either frost detection or time.
SFrost DetectionIf the compressor runs longer than
34 minutes and the actual difference between the clear
coil and frosted coil temperatures exceeds the maxi-
mum difference allowed by the control, a defrost cycle
will be initiated.
IMPORTANT − The demand defrost control will allow a
greater accumulation of frost and will initiate fewer de-
frost cycles than a time/temperature defrost system.
STimeIf 6 hours of heating mode compressor run time
has elapsed since the last defrost cycle while the coil
temperature remains below 35°F (2°C), the demand
defrost control will initiate a defrost cycle.
ActuationWhen the reversing valve is de−energized, the
Y1 circuit is energized, and the coil temperature is below
35°F (2°C), the board logs the compressor run time. If the
board is not calibrated, a defrost cycle will be initiated after
34 minutes of heating mode compressor run time. The con-
trol will attempt to self−calibrate after this (and all other) de-
frost cycle(s).
Calibration success depends on stable system tempera-
tures during the 20−minute calibration period. If the control
fails to calibrate, another defrost cycle will be initiated after
45 minutes (90 minutes −1 to −4 boards) of heating mode
compressor run time. Once the defrost board is calibrated,
it initiates a demand defrost cycle when the difference be-
tween the clear coil and frosted coil temperatures exceeds
the maximum difference allowed by the control OR after 6
hours of heating mode compressor run time has been
logged since the last defrost cycle.
NOTE − If ambient or coil fault is detected, the control will
not execute the TEST" mode.
TerminationThe defrost cycle ends when the coil tem-
perature exceeds the termination temperature or after 14
minutes of defrost operation. If the defrost is terminated by
the 14−minute timer, another defrost cycle will be initiated
after 34 minutes of run time.
Test ModeWhen Y1 is energized and 24V power is be-
ing applied to the control, a test cycle can be initiated by
placing the termination temperature jumper across the
Test" pins for 2 to 5 seconds. If the jumper remains across
the Test" pins longer than 5 seconds, the control will ignore
the test pins and revert to normal operation. The jumper will
initiate one cycle per test.
Enter the TEST" mode by placing a shunt (jumper) across
the TEST" pins on the control after power−up. (The
TEST" pins are ignored and the test function is locked out if
the shunt is applied on the TEST" pins before power−up).
Control timings are reduced, the low−pressure switch is ig-
nored and the control will clear any active lockout condi-
tion.
Each test pin shorting will result in one test event. For
each TEST" the shunt (jumper) must be removed for at
least 1 second and reapplied. Refer to flow chart (figure 7)
for TEST" operation.
Note: The Y1 input must be active (ON) and the O" room
thermostat terminal into board must be inactive.
Defrost Control Diagnostics
See table 2 to determine defrost control operational condi-
tions and to diagnose cause and solution to problems.

Page 8
If in COOLING Mode If in HEATING Mode If in DEFROST Mode
Short test pins for longer
than 1 second but less than
2 seconds
Short test pins for more than 2 seconds
Y1 Active (0" line inactive)
Test pin short REMAINS in place for more than 5 seconds Test pins short REMOVED before a
maximum of 5 seconds
Clear any short cycle lockout
and 5 strike fault lockout
function, if applicable. No
other functions will be
executed and unit will
continue in the mode it was
operating.
No further test mode
operation will be
executed until the test
short is removed and
reapplied.
The control will check for ambient
and coil faults (open or shorted).
If a fault exists, the unit will
remain in Heat Mode and no
further test mode operation will
be executed until the test short is
removed and re applied. If
no fault exists and ambient
temperature is below 35ºF, the
unit will go into Defrost mode.
The unit will terminate
defrost and enter Heat
Mode uncalibrated with
defrost timer set for 34
minute test. No further
test mode operation will
be executed until the test
short is removed and
reapplied.
Clear any short cycle lockout and 5 strike
fault lockout function, if applicable.
The unit will return to Heat mode uncalibrated with defrost
timer set for 34 minutes. No further test mode operation will
be executed until the test short is removed and re applied.
The unit will remain in Defrost mode
until termination on time or temperature
FIGURE 7

Page 9
Calibration Mode Sequence
Occurs after power up, after cooling operation, or if the coil temperature exceeds the termination
temperature while in Heat Mode.
DCB defaults to 34 minutes Time/Temperature Mode
Reset Compressor Runtime / Reset Three / Five Strike Counter
DEMAND MODE
Accumulate compressor run-
time while coil temperature
is below 35° F (2°C). When
the accumulated compres-
sor time exceeds 6 hours or
if the coil sensor indicates
frost is present on coil, go to
Defrost.
34 MIN. TIME/TEMP. MODE
Accumulate compressor run-
time while coil temperature
is below 35° F (2°C). When
the accumulated compressor
time exceeds 34 minutes go
to Defrost.
45 MIN. TIME/TEMP. MODE
(90 MIN. −1 TO −4 BOARDS)
Accumulate compressor run-
time while coil temperature is
below 35° F (2°C). When the
accumulated compressor
time exceeds 90 minutes go
to Defrost.
DEFROST
OUTDOOR FAN Off
Reversing Valve ON
W1 line ON
Monitor coil temperature
and time in defrost mode.
HOW DID DEFROST TERMINATE?
Coil temperature was
above 35°F (2°C) for 4
min. of the 14 min. de-
frost OR reached defrost
termination temp.
DCB’s 60L3901 and 46M8201
LO−PS Termination Option
selected. Defrost terminated by
pressure.
Defrosted for 14 min. with-
out the coil temp. going
above 35°F (2°C) for 4
min and coil did not reach
termination temp.
At termination of defrost the compressor
runtime counter is reset/Turn on Outdoor
FAN /Rev Valve & W1 turn off.
At Termination of Defrost
the compressor runtime
counter is reset/Turn on
Outdoor FAN/Rev valve &
W turn OFF
Attempt to Calibration−Temperature measurements are not taken
for the first few minutes of each heat demand. This is to allow coil
temperatures to stabilize. DCB has a maximum of 20 minutes of
accumulated compressor runtime in heat mode to calibrate DCB
This may involve more than one heating demand.
YES, calibration occurred Was stable coil temp. attained
within 20 minutes?
NO, DCB reverts to 45 min.
(90 min. −1 to −4 boards)
time/temp.
FIGURE 8

Page 10
TABLE 2
DS2
Green
DS1
Red Condition/Code Possible Cause(s) Solution
OFF OFF Power problem No power (24V) to control termi-
nals R & C or board failure.
1.Check control transformer power (24V).
2.If power is available to board and LED(s) do
not light, replace board.
Simultaneous
SLOW Flash
Normal operation Unit operating normally or in
standby mode.
None required.
Alternating
SLOW Flash
5−minute anti−short cycle
delay
Initial power up, safety trip, end of
room thermostat demand.
None required (Jumper TEST pins to override)
Simultaneous
FAST Flash
Ambient Sensor Problem Sensor being detected open or shorted or out of temperature range. Control will
revert to time/temperature defrost operation. (System will still heat or cool).
Alternating
FAST Flash
Coil Sensor Problem Sensor being detected open or shorted or out of temperature range. Control will not
perform demand or time/temperature defrost operation. (System will still heat or
cool).
ON ON Circuit Board Failure Indicates that control has internal component failure. Cycle 24 volt power to board.
If code does not clear, replace control.
FAULT & LOCKOUT CODES (Each fault adds 1 strike to that code’s counter; 5 strikes per code = LOCKOUT)
OFF SLOW
Flash
Low Pressure Fault 1.Restricted air flow over indoor
or outdoor coil.
2.Improper refrigerant charge in
1.Remove any blockages or restrictions from
coils and/or fans. Check indoor and outdoor
fan motor for proper current draws.
2
OFF ON Low Pressure LOCKOUT
Improper
refrigerant
charge
in
system.
3.Improper metering device
installed or incorrect operation
fan
motor
for
proper
current
draws.
2.Check system charge using approach & sub-
cooling temperatures.
3.Check system operating pressures and
SLOW
Flash
OFF High Pressure Fault
i
ns
t
a
ll
e
d
or
i
ncorrec
t
opera
ti
on
of metering device.
4.Incorrect or improper sensor
location or connection to s
y
s-
3
.
Ch
ec
k
sys
t
em opera
ti
ng pressures an
d
compare to unit charging charts.
4.Make sure all pressure switches and sensors
have secure connections to s
y
stem to prevent
ON OFF High Pressure LOCKOUT
location
or
connection
to
sys
tem.
have
secure
connections
to
system
to
prevent
refrigerant leaks or errors in pressure and
temperature measurements.

Page 11
B − Compressor (B1)
All 14HPX units utilize a scroll compressor. The scroll com-
pressor design is simple, efficient and requires few moving
parts. A cutaway diagram of the scroll compressor is shown in
figure 9. The scrolls are located in the top of the compressor
can and the motor is located just below. The oil level is immedi-
ately below the motor.
The scroll is a simple compression concept centered around
the unique spiral shape of the scroll and its inherent properties.
Figure 10 shows the basic scroll form. Two identical scrolls are
mated together forming concentric spiral shapes (figure 11).
One scroll remains stationary, while the other is allowed to "or-
bit" (figure 12). Note that the orbiting scroll does not rotate or
turn but merely orbits the stationary scroll.
FIGURE 9
SCROLL COMPRESSOR
DISCHARGE
SUCTION
NOTE − During operation, the head of a scroll compressor may
be hot since it is in constant contact with discharge gas.
FIGURE 10
SCROLL FORM
FIGURE 11
STATIONARY SCROLL
ORBITING SCROLL
DISCHARGE
SUCTION
CROSS−SECTION OF SCROLLS
TIPS SEALED BY
DISCHARGE PRESSURE
DISCHARGE
PRESSURE
The counterclockwise orbiting scroll draws gas into the outer
crescent shaped gas pocket created by the two scrolls (figure
12 − 1). The centrifugal action of the orbiting scroll seals off the
flanks of the scrolls (figure 12 − 2). As the orbiting motion con-
tinues, the gas is forced toward the center of the scroll and the
gas pocket becomes compressed (figure 12 − 3). When the
compressed gas reaches the center, it is discharged vertically
into a chamber and discharge port in the top of the compressor
(figure 11). The discharge pressure forcing down on the top
scroll helps seal off the upper and lower edges (tips) of the
scrolls (figure 11). During a single orbit, several pockets of gas
are compressed simultaneously providing smooth continuous
compression.
The scroll compressor is tolerant to the effects of liquid return.
If liquid enters the scrolls, the orbiting scroll is allowed to sepa-
rate from the stationary scroll. The liquid is worked toward the
center of the scroll and is discharged. If the compressor is re-
placed, conventional Lennox cleanup practices must be used.
Due to its efficiency, the scroll compressor is capable of draw-
ing a much deeper vacuum than reciprocating compres-
sors. Deep vacuum operation can cause internal fusite
arcing resulting in damaged internal parts and will result
in compressor failure. Never use a scroll compressor for
evacuating or pumping−down" the system. This type of
damage can be detected and will result in denial of war-
ranty claims.
The scroll compressor is quieter than a reciprocating com-
pressor, however, the two compressors have much differ-
ent sound characteristics. The sounds made by a scroll
compressor do not affect system reliability, performance,
or indicate damage.
See compressor nameplate and ELECTRICAL DATA
table on page 2 for compressor specifications.

Page 12
12
34
SUCTION
POCKET
SUCTION
ORBITING SCROLL
STATIONARY SCROLL
SUCTION
SUCTION
DISCHARGE
POCKET
SUCTION INTERMEDIATE PRESSURE
GAS
CRESCENT SHAPED
GAS POCKET
HIGH PRESSURE GAS
FLANKS SEALED
BY CENTRIFUGAL
FORCE
MOVEMENT OF ORBIT
FIGURE 12
C − Outdoor Fan Motor (B4)
All units use single−phase PSC fan motors which require a run
capacitor. In all units, the condenser fan is controlled by
the compressor contactor (and defrost control during
defrost cycles).
ELECTRICAL DATA tables in this manual show specifi-
cations for condenser fans used in 14HPXs.
Access to the condenser fan motor on all units is gained
by removing the seven screws securing the fan assem-
bly. See figure 13. The outdoor fan motor is removed
from the fan guard by removing the four nuts found on
the top panel. If replacing outdoor fan motor on the
14HPX−060, align motor shaft 1/4" from the hub. For all
other 14HPX model units, motor shaft should be flush
with hub. See figure 13. Drip loops should be used in wir-
ing when servicing motor.
D − Reversing Valve (L1) and Solenoid
A refrigerant reversing valve with electromechanical so-
lenoid is used to reverse refrigerant flow during unit op-
eration. The reversing valve requires no maintenance.
The only replaceable part is the solenoid. If the reversing
valve itself has failed, it must be replaced.
If replacement is necessary, access reversing valve by re-
moving the outdoor fan motor. Refer to figure 13.
FAN
CONDENSER FAN MOTOR
AND COMPRESSOR ACCESS
Remove (7) screws
REMOVE (7) SCREWS
SECURING FAN GUARD.
REMOVE FAN GUARD/
FAN ASSEMBLY.
FAN GUARD
WIRING
FIGURE 13
Remove (4) nuts
ALIGN FAN HUB
FLUSH WITH
MOTOR SHAFT.
ON −060 UNITS
SHAFT SHOULD
BE 1/4" FROM
HUB.
Make sure all power is disconnected before
beginning electrical service procedures.
DANGER

Page 13
E − High Pressure Switch (S4)
IMPORTANT
Pressure switch settings for R−410A refrigerant will
be significantly higher than units with R−410A.
An auto-reset, single-pole/single-throw high pressure switch
is located in the liquid line. This switch shuts off the compres-
sor when liquid line pressure rises above the factory setting.
The switch is normally closed and is permanently adjusted to
trip (open) at 590 + 10 psi. See Pressure Switch Circuit in
the Defrost Control description.
F − Low Pressure Switch (S87) (option)
An auto-reset, single-pole/single-throw low pressure
switch is located in the suction line. This switch shuts off the
compressor when suction pressure drops below the facto-
ry setting. The switch is closed during normal operating
pressure conditions and is permanently adjusted to trip
(open) at 25 + 5 psi. The switch automatically resets when
suction line pressure rises above 40 + 5 psi. Under certain
conditions the low pressure switch is ignored. See Pres-
sure Switch Circuit in the Defrost Control description.
G − Loss of Charge Switch (S24) (option)
The loss of charge switch is NC, auto re−set and located on
the suction line of the compressor. The switch opens when
suction line pressure exceeds the factory setting of 25 + 5
psig and shuts down the compressor. The switch closes at
55 psig + 5.
H − Start Kit (option)
The start kit consist of a potential relay K31 and start capac-
itor C7. The potential relay controls the operation of the
starting circuit. The relay is normally closed when contactor
K1 is de−energized. When K1 is energized, the compressor
immediately begins start up. K31 remains closed during
compressor start up and capacitor C7 remains in the cir-
cuit. When compressor reaches approximately 75% of its
speed, K31 is energized. When K31 energizes, the con-
tacts open and start capacitor C7 is taken out of the circuit.
I − Drier
A filter drier designed for all 14HPX model units is factory
installed in the liquid line. The filter drier is designed to re-
move moisture and foreign matter, which can lead to com-
pressor failure.
Moisture and / or Acid Check
Because POE oils absorb moisture, the dryness of the
system must be verified any time the refrigerant sys-
tem is exposed to open air. Acompressor oil sample
must be taken to determine if excessive moisture has been
introduced to the oil. Table 3 lists kits available from Lennox
to check POE oils.
If oil sample taken from a system that has been exposed to
open air does not test in the dry color range, the filter drier
MUST be replace.
IMPORTANT
Replacement filter drier MUST be approved for
HFC−410A refrigerant and POE application.
Foreign Matter Check
It is recommended that a liquid line filter drier be replaced
when the pressure drop across the filter drier is greater
than 4 psig. To safeguard against moisture entering the
system follow the steps in section III − sub section
E − "Evacuating the System" when replacing the drier.
J − Crankcase Heater (HR1) & Thermostat
(S40)
Crankcase heater HR1 and thermostat S40 are standard
on 14HPX−036, −042, −048 and −060 units and an option for
the other sizes. HR1 is a 40 watt heater that prevents liquid
from accumulating in the compressor. HR1 is controlled by
thermostat S40 located in the liquid line. When liquid line
temperature drops below 50° F, S40 closes energizing
HR1. S40 will open once liquid line temperature reaches
70°, de−energizing HR1.
TABLE 3
Acid and Moisture Test Kits
KIT CONTENTS TUBE SHELF LIFE
10N46 − Refrigerant Analysis Checkmate−RT700
10N45 − Acid Test Tubes Checkmate−RT750A (three pack) 2 − 3 years @ room temperature. 3+
years refrigerated
10N44 − Moisture Test Tubes Checkmate − RT751 Tubes (three
pack)
6 − 12 months @ room temperature. 2
years refrigerated
74N40 − Easy Oil Test Tubes Checkmate − RT752C Tubes (three
pack)
2 − 3 years @ room temperature. 3+
years refrigerated
74N39 − Acid Test Kit Sporian One Shot − TA−1

Page 14
II − REFRIGERANT SYSTEM
FIGURE 14
14HPX COOLING CYCLE (SHOWING MANIFOLD GAUGE CONNECTIONS)
OUTDOOR
COIL
EXPANSION/CHECK
VALVE
BIFLOW
FILTER / DRIER
TO
HFC−410A
DRUM
LOW
PRESSURE
HIGH
PRESSURE
COMPRESSOR
REVERSING VALVE
VAPOR
LINE
VALVE
MUFFLER
NOTE − ARROWS INDICATE DIRECTION OF REFRIGERANT FLOW
SERVICE
PORT
SUCTION
EXPANSION/CHECK
VALVE
INDOOR UNIT
OUTDOOR UNIT
LIQUID LINE
SERVICE
PORT
GAUGE MANIFOLD
DISTRIBUTOR
INDOOR
COIL
FIGURE 15
14HPX HEATING CYCLE (SHOWING MANIFOLD GAUGE CONNECTIONS)
OUTDOOR
COIL
EXPANSION/CHECK
VALVE
BIFLOW
FILTER / DRIER
TO
HFC−410A
DRUM
LOW
PRESSURE
HIGH
PRESSURE
COMPRESSOR
REVERSING VALVE
VAPOR
LINE
VALVE
MUFFLER
NOTE − ARROWS INDICATE DIRECTION OF REFRIGERANT FLOW
SERVICE
PORT
SUCTION
EXPANSION/CHECK
VALVE
INDOOR UNIT
OUTDOOR UNIT
LIQUID LINE
SERVICE
PORT
GAUGE MANIFOLD
DISTRIBUTOR
INDOOR
COIL

Page 15
A − Plumbing
Field refrigerant piping consists of liquid and vapor lines
from the outdoor unit (sweat connections). Use Lennox
L15 (sweat) series line sets as shown in table 4.
TABLE 4
Refrigerant Line Sets
Model Field
Connections Recommended Line Set
−018
−024
−030
3/8 in.
(10 mm)
3/4 in
(19 mm)
3/8 in.
(10
mm)
3/4 in
(19 mm)
L15−41
15 ft. − 50 ft.
(4.6 m − 15 m)
−036
−042
−048
3/8 in.
(10 mm)
7/8 in
(22 mm)
3/8 in.
(10
mm)
7/8 in
(22 mm)
L15−65
15 ft. − 50 ft.
(4.6 m − 15 m)
−060 3/8 in.
(10 mm)
1−1/8 in.
(29 mm)
3/8 in.
(10
mm)
1−1/8 in.
(29 mm)
Field
Fabricated
B − Service Valves
IMPORTANT
Only use Allen wrenches of sufficient hardness
(50Rc − Rockwell Harness Scale min). Fully in-
sert the wrench into the valve stem recess.
Service valve stems are factory torqued (from 9
ft lbs for small valves, to 25 ft lbs for large
valves) to prevent refrigerant loss during ship-
ping and handling. Using an Allen wrench rated
at less than 50Rc risks rounding or breaking off
the wrench, or stripping the valve stem recess.
The liquid and vapor line service valves (figures 16 and 17)
and gauge ports are accessible from outside the unit.
Each valve is equipped with a service port. The service ports
are used for leak testing, evacuating, charging and checking
charge. A schrader valve is factory installed. A service port cap
is supplied to protect the schrader valve from contamination
and serve as the primary leak seal.
NOTE-Always keep valve stem caps clean.
To Access Schrader Port:
1 − Remove service port cap with an adjustable wrench.
2 − Connect gauge to the service port.
3 − When testing is completed, replace service port cap.
Tighten finger tight, then an additional 1/6 turn.
To Open Liquid or Vapor Line Service Valve:
1 − Remove stem cap with an adjustable wrench.
2 − Using service wrench and hex head extension (5/16 for
vapor line and 3/16 for liquid line), back the stem out coun-
terclockwise until the valve stem just touches the retaining
ring.
3 − Replace stem cap and tighten finger tight, then tighten an
additional 1/6 turn.
Do not attempt to backseat this valve. Attempts to
backseat this valve will cause snap ring to explode
from valve body under pressure of refrigerant.
Personal injury and unit damage will result.
DANGER
To Close Liquid or Vapor Line Service Valve:
1 − Remove stem cap with an adjustable wrench.
2 − Using service wrench and hex head extension (5/16 for
vapor line and 3/16 for liquid line), turn stem clockwise to
seat the valve. Tighten firmly.
3 − Replace stem cap. Tighten finger tight, then tighten an
additional 1/6 turn.
FIGURE 16
LIQUID LINE SERVICE VALVE (VALVE OPEN)
SCHRADER
VALVE
SERVICE
PORT
SERVICE
PORT
CAP
INSERT HEX
WRENCH HERE
TO INDOOR COIL
TO COMPRESSOR
STEM CAP
SCHRADER VALVE OPEN
TO LINE SET WHEN VALVE IS
CLOSED (FRONT SEATED)
SERVICE
PORT
SERVICE
PORT
CAP
RETAINING RING STEM CAP
TO
COMPRESSOR
INSERT HEX
WRENCH HERE
LIQUID LINE SERVICE VALVE (VALVE CLOSED)
VALVE FRONT
SEATED
TO INDOOR COIL

Page 16
Vapor Line (Ball Type) Service Valve
A ball-type full service valve is used on 14HPX. Valves
are not rebuildable. If a valve has failed it must be replaced. A
ball valve is illustrated in figure 17.
The ball valve is equipped with a service port. A schrader valve
is factory installed. A service port cap is supplied to protect the
schrader valve from contamination and assure a leak free
seal.
SUCTION LINE (BALL TYPE) SERVICE VALVE
(VALVE OPEN)
FIGURE 17
SCHRADER CORE
SERVICE PORT
SERVICE
PORT
CAP
STEM CAP
FROM INDOOR COIL
TO COMPRESSOR
STEM
USE ADJUSTABLE WRENCH
ROTATE STEM CLOCKWISE 90_TO CLOSE
ROTATE STEM COUNTER-CLOCKWISE 90_TO OPEN
BALL
(SHOWN OPEN)
C − Pumping Down System
CAUTION
Deep vacuum operation (operating compressor
at 0 psig or lower) can cause internal fusite
arcing resulting in a damaged or failed
compressor. This type of damage will result in
denial of warranty claim.
The system may be pumped down when leak checking the
line set and indoor coil or making repairs to the line set or
indoor coil.
1− Attach gauge manifold.
2− Front seat (close) liquid line valve.
3− Start outdoor unit.
4− Monitor suction gauge. Stop unit when 0 psig is reached.
5− Front seat (close) suction line valve.
D − Leak Testing (To Be Done
Before Evacuating)
1− Attach gauge manifold and connect a drum of dry nitro-
gen to center port of gauge manifold.
2− Open high pressure valve on gauge manifold and
pressurize line set and indoor coil to 150 psig (1034
kPa).
3− Check lines and connections for leaks.
NOTE-The preferred method is to use an electronic leak or
Halide detector. Add a small amount of HFC−410A (3 to 5
psig [20kPa to 34kPa]) then pressurize with nitrogen to 150
psig.
4− Release nitrogen pressure from the system, correct any
leaks and recheck.
WARNING
Danger of explosion!
When using a high pressure gas such
as dry nitrogen to pressurize a refriger-
ant or air conditioning system, use a
regulator that can control the pressure
down to 1 or 2 psig (6.9 to 13.8 kPa).
WARNING
Fire, Explosion and Personal Safety
Hazard.
Failure to follow this warning could
result in damage, personal injury or
death.
Never use oxygen to pressurize or
purge refrigeration lines. Oxygen,
when exposed to a spark or open
flame, can cause damage by fire
and / or an explosion, that can re-
sult in personal injury or death.
E − Evacuating the System
1− Attach gauge manifold. Connect vacuum pump (with vac-
uum gauge) to center port of gauge manifold. With both
manifold service valves open, start pump and evacuate
indoor coil and refrigerant lines.
IMPORTANT
A temperature vacuum gauge, mercury vacuum
(U−tube), or thermocouple gauge should be used.
The usual Bourdon tube gauges are not accurate
enough in the vacuum range.
IMPORTANT
The compressor should never be used to evacu-
ate a refrigeration or air conditioning system.
2− Evacuate the system to 29 inches (737mm) vacuum. Dur-
ing the early stages of evacuation, it is desirable to stop
the vacuum pump at least once to determine if there is a
rapid loss of vacuum. A rapid loss of vacuum would indi-
cate a leak in the system and a repeat of the leak testing
section would be necessary.
3− After system has been evacuated to 29 inches
(737mm), close gauge manifold valves to center port,
stop vacuum pump and disconnect from gauge man-
ifold. Attach an upright nitrogen drum to center port of
gauge manifold and open drum valve slightly to purge

Page 17
line at manifold. Break vacuum in system with nitro-
gen pressure by opening manifold high pressure
valve. Close manifold high pressure valve to center
port.
4− Close nitrogen drum valve and disconnect from
gauge manifold center port. Release nitrogen pres-
sure from system.
5− Connect vacuum pump to gauge manifold center
port. Evacuate system through manifold service
valves until vacuum in system does not rise above
.5mm of mercury absolute pressure or 500 microns
within a 20−minute period after stopping vacuum pump.
6− After evacuation is complete, close manifold center port,
and connect refrigerant drum. Pressurize system
slightly with refrigerant to break vacuum.
III − CHARGING
This system is charged with HFC−410A refrigerant which
operates at much higher pressures than HCFC−22. The
recommended check expansion valve is approved for use
with HFC−410A. Do not replace it with a valve that is de-
signed to be used with HCFC−22. This unit is NOT ap-
proved for use with coils that include metering orifices or
capillary tubes.
The unit is factory−charged with the amount of HFC−410A
refrigerant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with a 15
foot (4.6 m) line set. For varying line set lengths and for
various indoor unit matchups, the refrigerant charge
must be adjusted per tables 6 (Page 19) and 7
(Page 19). A blank space is provided on the unit rating
plate to list the actual field charge.
IMPORTANT
Mineral oils are not compatible with HFC−410A. If oil
must be added, it must be a polyol ester oil.
A − Check indoor air before charging
Figure 18
IMPORTANT
CHECK AIRFLOW BEFORE CHARGING!
NOTE − Be sure that filters and indoor and outdoor coils are
clean before testing.
Cooling mode indoor airflow check
Check airflow using the Delta−T (DT) process (figure 18).
Heating mode indoor airflow check
Blower airflow (CFM) may be calculated by energizing
electric heat and measuring:
Stemperature rise between the return air and supply air
temperatures at the indoor coil blower unit,
Smeasuring voltage supplied to the unit,
Smeasuring amperage being drawn by the heat unit(s).
Then, apply the measurements taken in following formula
to determine CFM:
CFM =
Amps x Volts x 3.41
CFM
= 1.08 x Temperature rise (F)
B − Set Up for Checking and Adding Charge
Setup for charging
Connect the manifold gauge set to the unit’s service ports
(see figure 14):
Slow pressure gauge to vapor service port
Shigh pressure gauge to liquid service port
Close manifold gauge set valves. Connect the center man-
ifold hose to an upright cylinder of HFC−410A.
Calculating charge
If the system is void of refrigerant, first, locate and repair
any leaks and then weigh in the refrigerant charge into the
unit. To calculate the total refrigerant charge:
Amount
specified
on
nameplate
Adjust amt. for
variation in
line set length
(table 6)
Additional charge
specified per
indoor unit matchup
(table 7)
Total
charge
+ + =

Page 18
FIGURE 18
Step 1. Determine the desired DTMeasure entering air tempera-
ture using dry bulb (A) and wet bulb (B). DTis the intersecting value
of Aand B in the table (see triangle).
Step 2. Find temperature drop across coilMeasure the coil’s dry
bulb entering and leaving air temperatures (Aand C). Temperature
Drop Formula: (TDrop) = Aminus C.
Step 3. Determine if fan needs adjustmentIf the difference be-
tween the measured TDrop and the desired DT(TDrop–DT) is within
+3º, no adjustment is needed. See examples: Assume DT= 15 and
Atemp. = 72º, these C temperatures would necessitate stated ac-
tions:
Cº TDrop –DT=ºF ACTION
53º 19 – 15 =4Increase the airflow
58º 14 – 15 =−1 (within +3º range) no change
62º 10 – 15 =−5 Decrease the airflow
Step 4. Adjust the fan speedSee indoor unit instructions to in-
crease/decrease fan speed.
Changing air flow affects all temperatures; recheck temperatures to
confirm that the temperature drop and DT are within +3º.
DT
80 24 24 24 23 23 22 22 22 20 19 18 17 16 15
78 23 23 23 22 22 21 21 20 19 18 17 16 15 14
76 22 22 22 21 21 20 19 19 18 17 16 15 14 13
74 21 21 21 20 19 19 18 17 16 16 15 14 13 12
72 20 20 19 18 17 17 16 15 15 14 13 12 11 10
70 19 19 18 18 17 17 16 15 15 14 13 12 11 10
57 58 59 60 61 62 63 64 65 66 67 68 69 70
Temp.
of air
entering
indoor
coil ºF
INDOOR
COIL
DRY BULBDRY
BULB
WET
BULB
B
TDrop
19º
A
Dry−bulb
Wet−bulb ºF
A
72º
B
64º
C
53º
air flowair flow
All temperatures are
expressed in ºF
C − Pre− Charge Maintenance Checks
IMPORTANT
Use table 5 as a general guide when performing maintenance checks. This is not a procedure for charging the
unit (Refer to Charging / Checking Charge section). Minor variations in these pressures may be expected due
to differences in installations. Significant differences could mean that the system is not properly charged or that
a problem exists with some component in the system.
Table 5
Normal Operating Pressures − Liquid +10 & Vapor +5 PSIG*
14HPX−018 14HPX−024 14HPX−030 14HPX−036 14HPX−042 14HPX−048 14HPX−060
5F (5C)** Liquid / Vapor Liquid / Vapor Liquid / Vapor Liquid/ Vapor Liquid / Vapor Liquid / Vapor Liquid / Vapor
Cooling
65 (18) 226 / 140 233 / 137 238 / 138 220 / 138 223 / 125 231 / 136 243 / 136
70 (21) 244 / 141 252 / 138 263 / 139 236 / 140 241 / 130 248 / 139 263 / 137
75 (24) 263 / 142 271 / 140 279 / 139 256 / 141 261 / 134 271 / 140 282 / 138
80 (27) 283 / 143 292 / 141 299 / 140 276 / 142 282 / 138 291 / 142 306 / 139
85 (29) 302 / 144 314 / 142 324 / 141 298 / 143 302 / 139 312 / 143 327 / 140
90 (32) 328 / 145 338 / 143 340 / 142 321 / 144 326 / 140 335 / 144 351 / 141
95 (35) 351 / 146 361 / 145 375 / 145 344 / 144 349 / 141 359 / 145 376 / 142
100 (38) 376 / 147 387 / 146 397 / 145 369 / 146 374 / 142 384 / 146 401 / 143
105 (41) 402 / 148 412 / 147 424 / 147 394 / 147 399 / 143 411 / 148 426 / 145
110 (38) 430 / 149 441 / 148 454 / 150 421 / 148 428 / 145 439 / 149 452 / 146
115 (45) 465 / 150 471 / 151 485 / 150 449 / 149 455 / 146 468 / 150 484 / 148
Heating
60 (15) 346 / 139 352 / 138 338 / 137 350 / 134 373 / 139 355 / 130 351 / 117
50 (10) 323 / 117 331 / 114 334 / 112 331 / 117 363 / 117 336 / 113 333 / 105
40 (4) 306 / 98 304 / 99 312 / 93 313 / 97 348 / 97 315 / 88 316 / 88
30 (−1) 278 / 84 299 / 80 302 / 74 298 / 83 336 / 74 296 / 72 308 / 70
20 (−7) 273 / 66 283 / 66 280 / 53 284 / 66 322 / 64 286 / 64 300 / 61
*IMPORTANTThese are most−popular−match−up pressures. Indoor match up and indoor load cause
pressures to vary.
**Temperature of the air entering the outside coil (outdoor ambient temperature).

Page 19
D − Charge using Weigh−in Method
Weigh−in:
1. Recover the refrigerant from the unit.
2. Conduct leak check; evacuate as previously outlined.
3. Weigh in the unit nameplate charge plus any charge
required for lineset differences from 15 feet and any
extra indoor unit matchup amount per table 7. (If
weighing facilities are not available, use the subcooling
method.)
TABLE 6
Liquid Line
Set Diameter
Oz. per 5 ft. (g per 1.5m) adjust from
15 ft. (4.6m) line set*
3/8 in. (9.5mm) 3 ounce per 5 ft. (85g per 1.5m)
NOTE − *If line length is greater than 15 ft. (4.6 m), add this amount.
If line length is less than 15 ft. (4.6 m), subtract this amount.
E − Charge using Subcooling Method
Requirementsthese items are required for charging:
SManifold gauge set connected to unit.
SThermometers for measuring outdoor ambient, liquid
line, and vapor line temperatures.
When to use cooling modeWhen outdoor temperature
is 60°F (15°C) and above, use cooling mode to adjust
charge.
When to use heating modeWhen the outdoor tempera-
ture is below 60°F (15°C), use the heating mode to adjust
the charge.
Adding Charge for Indoor MatchupsTable 7 lists all
the Lennox recommended indoor unit matchups along with
the charge levels for the various sizes of outdoor units.
TABLE 7
Adding Charge per Indoor Unit Matchup using Subcooling Method
Use
cooling
mode
Use
heating
mode
1. Check the airflow (figure 18) to be sure the indoor airflow is as required. (Make any air
flow adjustments before continuing with the following procedure.)
2. Measure outdoor ambient temperature; determine whether to use cooling mode or
heating mode to check charge.
3. Connect gauge set.
4. Check Liquid and Vapor line pressures. Compare pressures with Normal Operating
Pressures table 5, (Table 5 is a general guide. Expect minor pressures variations.
Significant differences may mean improper charge or other system problem.)
5. Set thermostat for heat/cool demand, depending on mode being used:
Using cooling modeWhen the outdoor ambient temperature is 60°F (15°C) and above.
Target subcooling values in table below are based on 70 to 80°F (21−27°C) indoor return
air temperature; if necessary, operate heating to reach that temperature range; then set
thermostat to cooling mode setpoint to 68ºF (20ºC). When pressures have stabilized,
continue with step 6..
Using heating modeWhen the outdoor ambient temperature is below 60°F (15°C).
Target subcooling values in table below are based on 65−75°F (18−24°C) indoor return air
temperature; if necessary, operate cooling to reach that temperature range; then set
thermostat to heating mode setpoint to 77ºF (25ºC). When pressures have stabilized,
continue with step 6..
6. Read the liquid line temperature; record in the LIQº space.
7. Read the liquid line pressure; then find its corresponding temperature in the temperature/
pressure chart (table 8) and record it in the SATº space.
8. Subtract LIQº temp. from SATº temp. to determine subcooling; record it in SCº space.
9. Compare SCº results with table below, being sure to note any additional charge for lineset
and/or matchup.
10. If subcooling value is greater than shown in table, remove refrigerant; if less than
shown, add refrigerant.
11.If refrigerant is added or removed, repeat steps 5. through 10. to verify charge.
60ºF (15ºC)
SATº
LIQº –
SCº =
INDOOR HEAT
MATCHUP PUMP
SubcoolTarget
HeatingCooling
(+5ºF)(+1ºF)
*Add
charge
INDOOR HEAT
MATCHUP PUMP
SubcoolTarget
HeatingCooling
(+5ºF)(+1ºF)
*Add
charge
INDOOR HEAT
MATCHUP PUMP
SubcoolTarget
HeatingCooling
(+5ºF)(+1ºF)
*Add
charge
14HPX−018 lb oz 14HPX−030 (cont’d) lb oz 14HPX−042 (cont’d) lb oz
CBX27UH−018/024 13 7 0 8 CX34−31A/B 11 6 1 6 CX34−62C, −62D 12 6 0 9
CBX32MV−018/024 15 7 0 0 CX34−38A/B 11 6 2 3 CX34−49C 12 6 0 7
14HPX−024 lb oz CX34−43B/C 15 11 2 14 CX34−60D 12 6 0 4
CH23−41 16 8 0 2 14HPX−036 lb oz 14HPX−048 lb oz
CBX26UH−024 25 7 0 0 CBX26UH−036 26 5 0 0 CH23−68 20 9 2 9
CBX27UH−018/024 15 8 1 2 CBX26UH−037 25 4 1 9 CBX26UH−048 8 7 1 9
CBX32M−018/024 16 8 0 14 CBX27UH−036 13 6 0 3 CBX27UH−048 11 8 1 2
CBX32M−030 15 8 1 3 CBX32M−036 13 6 0 2 CBX32M−048, −060 11 8 1 2
CBX32MV−018/024 16 8 0 14 CBX32M−042 13 6 0 3 CBX32MV−048, −060 11 8 1 2
CBX32MV−024/030 15 8 1 2 CBX32MV−036 13 6 0 3 CBX32MV−068 10 7 1 12
CH33−42B 14 11 1 10 CBX32MV−048 11 8 2 5 CH33−50/60C 11 8 1 1
CH33−36A 16 8 1 0 C33−44C 13 6 0 0 CH33−62D 10 7 1 14
CH33−36C 16 8 0 4 CH33−50/60C 11 8 2 5 CH33−60D 11 8 0 0
CR33−30/36A/B/C 25 7 0 2 CH33−44B 13 6 1 7 CR33−50/60C 35 5 0 0

Page 20
CX34−25A/B 16 8 0 14 CH33−48B 13 6 1 8 CR33−60D 37 6 0 0
CX34−31A/B 15 8 1 3 CR33−50/60C 25 4 1 15 CBX33−048, −060 12 8 1 2
CX34−36A/B/C 16 8 1 8 CR33−48B/C 25 5 0 9 CX34−62C, −62D 10 7 1 7
CX34−38A/B 14 11 2 2 CX34−49C 13 6 2 4 CX34−49D 11 8 0 14
14HPX−030 lb oz CX34−43B/C, −50/60C 13 6 1 8 CX34−60D 11 8 0 0
CH23−41 11 6 0 8 CX34−38A/B, −44/48C 13 6 0 0 14HPX−060 lb oz
CH23−51 6 6 1 12 14HPX−042 lb oz CH23−68 12 5 0 0
CBX26UH−024 30 8 0 6 CH23−68 20 9 0 13 CBX26UH−048 12 7 1 0
CBX26UH−030 29 8 2 3 CBX26UH−042 27 6 0 0 CBX26UH−060 14 4 0 0
CBX27UH−030 11 6 2 4 CBX27UH−042 12 6 0 8 CBX27UH−060 12 5 0 0
CBX32M−030 11 6 1 6 CBX32M−048 12 6 0 7 CBX32M−048, −060 12 5 0 0
CBX32M−036 11 6 2 4 CBX32MV−048 12 6 0 8 CBX32MV−048, −060 12 5 0 0
CBX32MV−024/030 11 6 1 6 CH33−62D 12 6 0 10 CBX32MV−068 12 7 1 0
CBX32MV−036 11 6 2 4 CH33−50/60C 12 6 0 7 CH33−50/60C 12 5 0 0
C33−44C 11 6 2 3 CH33−60D 12 6 0 4 CH33−62D 12 5 0 0
CH33−36C 11 3 0 0 CR33−50/60C,−60D 26 6 0 4 CBX33−060 12 8 0 0
CH33−42B 6 6 1 12 CBX33−042,−048 12 7 0 4 CX34−62C, −62D 12 7 1 0
CR33−30/36A/B/C 30 8 0 8 CBX33−060 12 6 0 7
*Add charge = Extra matchup amount required in addition to charge indicated on Heat Pump nameplate (remember to also add any charge required for lineset differ-
ences from 15 feet).