Lennox MWCB Series User manual

USER GUIDE
©2022 Lennox Industries Inc.
Dallas, Texas, USA
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) or a service
agency.
General
This wall-mounted indoor unit is matched with an outdoor
air conditioner unit to create a mini-split system that uses
HFC-410A refrigerant.
MWCB and MWHB
Series Units
SINGLE-ZONE MINI-SPLIT SYSTEM
(115V and 208/230V)
508242-01 1/2022
Table of Contents
General...........................................................................1
Optimal Performance......................................................1
Unit Parts........................................................................2
Features .........................................................................3
Auto Restart.................................................................3
Louver Angle Memory..................................................3
Refrigerant Leakage Detection....................................3
Louver Adjustment..........................................................3
Return Air Filters.............................................................3
Cleaning Return Air Filters...........................................3
Operation (Manual) - Force Cooling Mode.....................4
Operation (Wireless Remote Controller) ........................4
Requirements ..............................................................4
Remote Control Specications ....................................4
Wireless Remote Controller Button Functions.............5
Wireless Remote Controller Screen Indicators............6
Wireless Remote Controller Operation........................7
Wireless Remote Controller Set Button Function ........7
Troubleshooting..............................................................8
FCC Compliance Statement — PART 15.19..................8
THIS MANUAL MUST BE LEFT WITH THE OWNER
FOR FUTURE REFERENCE
Optimal Performance
Optimal performance for the COOL, HEAT and DRY
modes can be achieved in the following temperature
ranges. When your system is used outside of these
ranges, certain safety protection features will activate and
cause the unit to perform less than optimally.
Table 1. Cool, Heat and Dry Modes Optimal
Performance Ranges
Temp
Location COOL
HEAT
(Heat Pump
Units Only)
DRY
Room 60°F - 90°F
(16°C - 32°C)
32°F - 86°F
(0°C - 32°C)
50°F - 90°F
(10°C - 32°C)
Outdoor
5°F - 122°F
(-15°C to
50°C)
5°F - 86°F
(-15°C to
30°C)
32°F - 122°F
(0°C - 50°C)
To further optimize the performance of your unit, do the
following:
• Keep doors and windows closed.
• Limit energy usage by using TIMER ON and TIMER
OFF functions.
• Do not block air inlets or outlets.
• 
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.

2
Unit Parts
Display Code
Descriptions
Wireless
Remote Control Remote Control Holde
r
Return Air Filter
Louver
Front Panel
when Active Clean feature is turned on
Display window
Displays temperature, operation feature and
error codes:
for 3 seconds when:
• SWING, TURBO, ECO,or SILENCE feature is turned on
for 3 seconds when:
• TIMER OFF is set
• SWING, TURBO, ECO,or SILENCE feature is turned off
when defrosting
when 47°F (8.3°C) heating feature is turned on
• TIMER ON is set (if the unit is OFF, remains on when TIMER ON is set )
Figure 1. Components
WARNING
ELECTRICAL SHOCK, FIRE, OR EXPLOSION HAZARD.
DO NOT spray water on the indoor unit for any reason.
Do not touch the unit or the controller if your hands are
wet.
Do not insert your hands, tools or any other item into the
air intake or air outlet at either the indoor or outdoor unit.
Do not remove the outdoor unit fan guard for any reason.
CAUTION
If outdoor unit is installed on a raised stand, check
condition of stand occasionally to ensure that it remains
stable.
Do NOT install sprinklers or soaker hoses where they
can expose the outdoor unit to treated water. Prolonged
exposure to treated water will corrode the surface of
the steel and aluminum parts and will diminish the
performance of the unit.
IMPORTANT
System operation is controlled by either the provided
wireless or optional wired remote control. Refer to the
manual provided with the control for system operation.
To ensure comfort, make sure that temperature selection
has been properly set at the unit controller or wireless
remote control.
         
outlet at either the indoor or outdoor unit.
Do not stand on outdoor unit or store items on top of unit.
Make sure that indoor unit directional louvers are properly
adjusted.

3
Features
Auto Restart
If the unit loses power, it will automatically restart with the
prior settings once power has been restored.
Louver Angle Memory
When turning on your unit, the louver will automatically
resume its former angle operation.
Refrigerant Leakage Detection
The indoor unit will automatically display “EC” when it
detects refrigerant leakage. For a detailed explanation of
your unit’s advanced functionality (such as TURBO mode
and its self-cleaning functions), refer to “Operation (Wireless
Remote Controller)” on page 4.
Louver Adjustment
IMPORTANT
DO NOT adjust the louvers by hand. Louvers are
adjustable only by using the furnished wireless remote
controller or optional wired controller.
Use the furnished wireless remote control or optional wired
controller to set the position of the discharge air louvers.
The louvers may be set to automatically swing between
the outward and downward positions, OR you may set the
louvers so that they are stationary in a single position. It is
always recommended to direct the horizontal discharge air
louvers outward while cooling.
Cooling operation
Set horizontal louvers outward
.
Auto-swing operation
Set louvers to swing up and down automatically
.
Figure 2. Louver Operation
Refer to the wireless remote control section on using the
swing and direct buttons.
Return Air Filters




area with a large amount of dust.
          


Cleaning Return Air Filters
         
necessary. Lift the front panel of the indoor unit.
1. 
towards yourself.
2. 
3. 
only mild detergent.
Filter Tabs


Figure 3. Filter Removal and Service
4.          
shake off excess water.
5. 

6. 
7. Close the front panel.

4
Operation (Manual) - Force Cooling Mode
In the event that your remote control fails to work, your unit
can be operated manually with the MANUAL CONTROL
button located on the indoor unit.
Figure 4. AUTO/COOL Control Button
IMPORTANT
Unit must be turned off before using AUTO/COOL
operation procedures.
To operate your unit manually:
1. Open the front panel of the indoor unit.
2. Locate the AUTO/COOL button on the right-hand side
of the unit.
3. Press the AUTO/COOL button to activate FORCED
AUTO mode. Both FORCE HEATING and COOLING is
preset to 75ºF (24ºC) and cannot be manually adjusted.
4. Press the AUTO/COOL     
seconds to activate FORCED COOLING mode. The
       
rated frequency), and the indoor fan runs at high speed
(80%). Force cooling mode is preset to 75ºF (24ºC) and
cannot be manually adjusted.
NOTE: When system receives signals, such as switch on,
switch off, timer on, timer off, mode setting, fan
speed setting, sleep mode setting and follow me
setting, the forced operation will stop.
5. Press the AUTO/COOL      
seconds to activate FORCE DEFROSTING mode
(applicable to heat pump systems only). Indoor fan will
stop, defrosting lamp will light on.
6. Press the AUTO/COOL button again for 5 seconds to
turn the unit off.
7. Close the front panel.
Operation (Wireless Remote Controller)
IMPORTANT!
Frequent changes to operating mode may cause system
malfunction. Allow at least one minute between mode
changes for the system to stabilize.
Requirements
Using the remote controller
• Point the remote controller directly at the indoor unit.
• Stand within 26 feet (8 meters) of the indoor unit.
• Do not block the signal between the remote controller
and indoor unit.
NOTE: The remote controller will not function without a
clear line of sight to the indoor unit.
• Do not submerge the remote controller in liquid.
• Do not expose to direct sunlight.
• Do not drop or step on remote controller.
Remote control holder

holder to any suitable vertical surface such as a wall.
Remote Control Specications
Table 2. Specications
Rated voltage 3.0 VDC (2 AAA batteries)
Min voltage for sending signal
to CPU 2.4 VDC
Effective transmitting distance 26 feet (8 meters)
Operation conditions 23°F to 140°F (-5 to 60°C)

5
Wireless Remote Controller Button Functions
1
3
2
4
5
7
6
10
11
13
9
12
8
1. ON/OFF Button
Turns system on and off
2. UP/DOWN Buttons
Increase or decrease the indoor temperature in one degree
increments (maximum 86°F, minimum 60°F)
NOTE: Temperature cannot be adjusted in FAN mode.
NOTE: Press and hold both buttons for three seconds to
alternate the temperature display between the °C
and °F scale.
3. SET Button
Scrolls through unit operations in this order:
• Sleep
• Follow Me
     
the OK
4. FAN Button
Cycles fan speeds in the following order:
AUTO - 20% - 40% - 60% - 80% - 100%
NOTE: Holding Fan button down for 2 seconds will activate
Silence feature.
5. TURBO Button
Enables the unit to reach the preset temperature during
cooling or heating operation in the shortest time
6. MODE Button
• Select system operation modes
• Press button to cycle through each setting as follows:
AUTO > COOL > DRY > HEAT > FAN.
NOTE: HEAT setting is only available on heat pump models.
7. ECO / GEAR Button

NOTE: Only available in cooling mode.
ECO Operation
• Sets unit to 75°F unit operation if setpoint is lower
• Sets fan to Auto operation if setpoint is over 75°F
NOTE: If setpoint is manually changed to less than 75°F,
ECO operation is canceled.
GEAR Operation
Reduces electrical consumption to 75% or 50%
8. OK Button

9. TIMER Button
a. Initiates an auto-on or auto-off time sequence
b. Press TIMER button to initiate the ON time sequence
c. Press the UP / DOWN buttons multiple times to set
the desired time to turn on the unit
d. Press TIMER button to initiate the off time sequence.
e. To cancel, set timer to 0.0 or turn remote off and on.
NOTE: Each press of the button increases or decreases
the time (depending on function) in 30 minute
increments up to 10 hours.
Above 10 hours each press of the button will
increase or decrease the auto-timed setting by 60
minutes up to 24 hours.
10.SWING Button

11. Breeze Away Button
blowing on the body.
NOTE: This feature is available under Cool, Fan and Dry
modes only
12.Clean Button
Used to start/stop the Active Clean function
13.LED Button
Turns the LCD display back-light on the indoor unit on or off
NOTE: Press and hold the button for ve seconds to display
the actual room temperature. Press more than ve
seconds to revert back to display set temperature.

6
Wireless Remote Controller Screen Indicators
Information is displayed when the Wireless Remote Controller is powered on.
Transmission Indicator
MODE display
TIMER ON display
FAN SPEED display
TIMER OFF display
Silence feature
display
ECO display
GEAR display
LOCK display
Up/Down louver swing
display
Not applicable to this
model.
TURBO mode display
Not applicable for
this unit
Temperature/Timer/Fan speed
/
Relative Humidity display
Active Clean feature display
Sleep feature display
Follow Me feature display
Not applicable for this unit
Low battery detection (flashing)
Note:
All icons are shown for display purposes only.
During actual unit operation, only active icons are displayed.
Displays when LOCK feature
is activated.
Silence
LOW
MED
HIGH
AUTO
Lights up when remote
sends signal to indoor
unit
Displays selected fan speed:
Displays the current
including:
mode,
2%-20%
21%-40%
41%-60%
61%-80%
81%-100%
1%
NOTE - Fan speed cannot be
adjusted in AUTO or DRY mode.
Displays when ECO
feature is activated
Displays when GEAR
feature is activated
Displays the set temperature
by default, or fan speed or
timer setting when using
TIMER ON/OFF functions.
Temperature range:
Timer setting range:
0-24 hours
Fan speed setting range:
AU -100%
This display is blank when
operating in FAN mode.
gg
ggg
Breeze Away feature display
60-86°F / 16-30°C

7
Wireless Remote Controller Operation
Auto Operation
1. Press the MODE button to select Auto.
2. Press the UP/DOWN button to set the desired
temperature.
3. Press the ON/OFF button to start the system.
Cooling /Heating Operation
1. Press the MODE button to select COOL or HEAT mode.
2. Press the UP/DOWN buttons to set the desired
temperature.
3. Press the FAN button to select the fan speed in four
steps which are Auto, Low, Med or High.
4. Press the ON/OFF button to start the system.
Dehumidifying Operation
1. Press the MODE button to select DRY mode.
2. Press the ON/OFF button to start the unit.
Timer ON/OFF Operation
1. Press the TIMER button. The remote controller shows
TIMER ON or TIMER OFF icon
2. Press the TIMER button again to set desired time.
Each time you press the button, the time increases by
30 minutes between 0 and 10 hours and by 60 minutes
between 10 and 24 hours.
3. After setting the TIMER ON or TIMER OFF there will
be a one second delay before the remote controller
transmits the signal to the unit. After approximately two
seconds the set temperature will re-appear on the LCD
display window.
Silence Operation
Press the FAN button for more than two seconds to activate
or disable the Silence function
Lock Function
Press the Clean and Turbo buttons at the same time for
more than 5 seconds to activate Lock function. All buttons
will not response except pressing the same two buttons for
two seconds again to disable locking.
Swing Function
1. Press the SWING button to activate up/down louver
operation. Louvers oscillate up and down automatically.
2. Press and hold the SWING button again to disable.
NOTE: Pressing the SWING button multiple times will set
the louvers at ve different xed airow angles.
Wireless Remote Controller Set Button Function
Breeze Away
Prevents unit from blowing air directly on a person
NOTE: Only available in COOL, FAN or DRY modes.
Active Clean
• Removes dust, mold, and grease that may cause odors
when it adheres to the indoor coil by automatically
freezing and then rapidly thawing the coil
• Indoor unit displays “CL”
• After 20 to 45 minutes the unit will automatically cancel
the operation.
NOTE: Only available in COOL or DRY modes.
Sleep
Enables the system to automatically increase cooling or

hours, then maintain a steady temperature for 6 hours
System returns to the previous operating mode after 8 total
hours of operation
NOTE: To cancel, push the MODE, FAN SPEED or
ON/ OFF buttons.
SLEEP mode is only available when the unit is in COOL,
HEAT or AUTO mode
NOTE: While in sleep mode these features (active clean,
silence feature, breeze away function, refrigerant
leakage detection and Eco features) are not
available.
Follow Me
Allows remote temperature sensing of the room at the
remote controller location.

8
Troubleshooting
If any of the following faults codes appear on your indoor unit, please
contact your licensed professional HVAC installer (or equivalent) or a
service agency.
Table 3. Indoor Display Alert and Status Codes and
Outdoor Unit LED
Unit Error and Operation Codes
Indoor
Unit
Display
System Error Codes
Indoor unit EEPROM error EH 00
Indoor unit EEPROM parameter error EH 0A
Communication error between indoor unit and outdoor
units EL 01
Indoor fan speed error (DC motor) EH 03
Indoor room temperature sensor error (T1) EH 60
Indoor coil temperature sensor error (T2) EH 61
Refrigerant leakage detection (Cooling mode only) EL 0C
Outdoor current overload protection PC 08
Outdoor ambient temperature sensor error (T4) EC 53
Outdoor coil temperature sensor error (T3) EC 52
Compressor discharge temperature sensor error (T5) EC 54
Outdoor unit EEPROM error EC 51
Outdoor unit fan speed error (DC fan motor) EC 07
Inverter module IPM error PC 00
High or Low voltage protection PC 01
Outdoor low ambient temperature protection PC 0L
Compressor drive error PC 04
Communication error between main control board and
display board EH 0b
Operational Status Codes
46F heat mode (available on heat pump systems only) FP
Force Cooling FC
Remote or Wired controller Lock LL
Defrost (available on heat pump systems only) dF
Active clean CL
Time On On
Time Off OF
Anti-cold Air Flow (available on heat pump systems only) cF
Remote On/Off CP
ECO mode On display
3 seconds
Outdoor Unit LED:


FCC Compliance Statement — PART 15.19
PART 15.19 This device complies with Part 15 of the FCC
Rules. Operation is subject to the following two conditions:
1. This device may not cause harmful interference, and
2. This device must accept any interference received,
including interference that may cause undesired
operation. FCC Interference Statement — PART
15.105 (B).
3. This equipment has been tested and found to comply
with the limits for a Class B digital device, pursuant to
Part 15 of the FCC Rules. These limits are designed
to provide reasonable protection against harmful
interference in a residential installation.
4. This equipment generates, uses and can radiate radio
frequency energy and, if not installed and used in
accordance with the instructions, may cause harmful
interference to radio communications. However, there
is no guarantee that interference will not occur in a
particular installation. If this equipment does cause
harmful interference to radio or television reception,
which can be determined by turning the equipment
off and on, the user is encouraged to try to correct the
interference by one of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment
and receiver.
• Connect the equipment into an outlet on a circuit
different from that to which the receiver is connect-
ed.
• Consult the dealer or an experienced radio/TV
technician for help.
RF Exposure Information
This equipment complies with FCC radiation exposure
limits set forth for an uncontrolled environment. In order to
avoid the possibility of exceeding the FCC radio frequency
exposure limits, human proximity to the antenna shall not
be less than 20cm during normal operation.