Lennox M0STAT64Q-2 Installation instructions

1
INSTALLATION/
OPERATION
INSTRUCTIONS
CONTROLS
507644-03 10/2021
Supersedes 507644-02
This manual must be left with the
owner for future reference.
M0STAT64Q-2 Indoor Unit
Programmable Controller
(22U20)
©2021 Lennox Industries Inc.
Dallas, Texas, USA
IMPORTANT
Frequent changes to operating mode may
cause system malfunction. Allow at least
one minute between mode changes to
allow the system to stabilize.
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 service agency.
Shipping and Packing List
Package 1 of 1 catalog number 22U20 contains:
1 – Wired Controller
1 – Lithium battery
3 – Screws (mount to wall)
2 – Screws (mount to J-box)
2 – Plastic spacers (J-box)
1 – Connection Cable A with connector for all indoor
units
1 – Connection Cable B with connector for MMDA/B,
MCFA/B, M22A and M33A/B/C indoor units
1 – Connection Cable C with connector for MWMA/B
indoor units
1 – Connection Cable D for MWMC indoor unit
1 – Installation and operation manual
Specications
Input voltage 5 VDC
Ambient temperature 23~110°F (-5~43°C)
Ambient humidity RH40%~RH90%

2
General
The M0STAT64Q is a wired programmable local
controller for mini-split indoor units with conve-
nient timed schedules for daily operation. These
instructions are intended as a general guide and
do not supersede local codes in any way. Con-
sult authorities having jurisdiction before instal-
lation.
Requirements
Be sure that power supply has been turned off
before beginning installation. This controller
should be used only as described in this man-
ual. Do not install the controller on outside walls
(where there is unconditioned space on opposite
side of wall) or in locations where direct sunlight
may be present.
Wiring Connections
Dimensions
123mm
(4.8”)
120mm
(4.7”) 18.5mm
(0.7”)
83.5mm
(3.3”)
46mm
(1.8”)
62mm
(2.4”)
Figure 1. M0STAT64Q Dimensions
WARNING
Be sure that power supply has been turned
off before beginning installation.
CAUTION
Clean controller using a clean, damp
cloth. Do not spray cleanser on or around
controller.
WARNING
Do not operate controller with wet hands.
CAUTION
Do not install controller in areas where
heavy oil, vapor, or gases containing
sulfur may exist or the controller may be
damaged.

3
• This manual provides the installation instruc-
tions for this controller. Refer to the included
wiring diagrams to connect the controller to
the indoor unit.
• The controller uses low voltage. Keep a mini-
mum distance of 12” (305 mm) between low
voltage control wire and high voltage power
wires.
• Ground the shielded control wiring.
1. Use the wiring connections illustrations (Fig-
ures 2 and 6) to connect the controller to the
indoor unit. NOTE - Connection details for
wall-mounted units differ from the other indoor
unit types.
2. Select the cable exit route from the back of
the controller.
3. Include a drip loop in the cable.
IMPORTANT
Read all of the information in this manual be-
fore using this controller. All wiring must con-
form to local and national building and elec-
trical codes and ordinances. This is a 5 VDC
controller. Do not install on voltages higher
than 5 VDC.
IMPORTANT
The provided cables must be used. Do not
use excessive force while pulling the cable or
when making the connections.
• Do not use a megger to test insulation.
• The controller cable length should not exceed
164 ft (50 m).
Indoor unit main board
Receiver board
Cable A
CN40
Cable B
3 ft. 7 in. (1.1m)
4-conductor shielded
wire on the controller
(Gray cable with blue tag for all units
that require the WYE cable.)
Figure 2. Wiring Connections MMDA/B, MCFA/B, M22A and M33A/B/C

4
Figure 3. MMDA/B Main Board
Figure 4. M22A and M33A/B/C Main Board
CN 40
Connect to
controller
CN 40
Connect to
controller
Figure 5. MCFA/B Main Board
CN 40
Connect to
controller
Co nnectthe
ProgrammableWired
Co ntrollertothe factory
installedCN4 portcable
Figure 6. MFMA Main Board

5
Figure 7. Wiring Connections MWMA/B
Figure 8. MWMA/B Receiver Board
CN 403
Connect to
controller
Receiver board
4-conductor shielded wire on the controller
Cable C
CN403
Cable A
NOTE - CN 403 is used to connect either the M0STAT64Q local controller OR a centralized control. It is not possible to connect
both the M0STAT64Q controller and a centralized control to this unit.
Factory-connected to
Display Board
Receiver board Display board
4-core shielding wire on the controller
The connection cable A
CN1
CN40
XYE5V
White
Yellow Brown
Red
The connection cable D
Figure 9. Wiring Connections MWMC

6
MWMC receiver board uses terminals for the
programmable wired controller.
Figure 10. MWMC Receiver board
Wire Controller Cable
Indoor unit main board
CN20
CN1
CN4
Factory installed
Adapter Board
Factory installed
CN4 Adapter Cable
Optional Programmable
Wired Controller
20 Foot Cable provided with
Programmable Wired Controller
Figure 11. Wiring Connections to MFMA

7
4. Seal the cable entrance to the controller cas-
ing and any wall penetrations to prevent water
Figure 12. Select Cable Route
PCB
PCB
PCB
1
1
1
2
3
¹Use snips to notch the
controller casing to allow
the cable to pass through.
from entering the controller.
5. Reattach the controller to the back plate. Be
careful not to pinch or bind the wires.
Figure 13. Prevent Water from Entering
Controller Casing
Sealant Drip
Loop
Drip
Loop
Drip
Loop
Sealant Sealant
Figure 14. Reattach Controller to Back Plate

8
1. Remove the controller from the back plate us-
ing a at-head screwdriver.
2. Mount the back plate as appropriate for your
application.
Figure 15. Remove Back Plate
Slots
Figure 16. Attach Back Plate to Wall
Back plate
Screws (M4×20)
Figure 17. Attach Back Plate to J-box
Switch box
Back plate
Screw (M4×20)
Screws (M4×25)
3. J-box installation - Adjust the length of the two
plastic spacers as needed to allow the control-
ler to be mounted ush with the wall.
NOTE – Be sure to provide for future mainte-
nance by allowing enough slack in the wiring to
allow the controller to be removed from the wall
if needed.
Installation
4. Insert the provided battery into controller,
positive side out. The battery stores the day
and time in case of power outage. Replace
the battery when it’s charge is depleted.
5. Reattach the controller to the back plate. Be
careful not to pinch or bind the wires.

9
Display
Operation
Mode
Fan
Speed
Horizontal and Vertical Swing
(not available for all indoor unit models)
Faceplate
Function
On/Off Timer
Schedule
Follow me
Function Turbo/PTC
°F or °C
¹Tempera-
ture display
Lock
Indication
Room
Temperature
Clock
¹ Displays cooling set point, heating set point
or room temperature
Not
Used

10
Description of Buttons
Power
Decrease
Fan speed
(Lock)
Swing but-
ton (Swing
function not
available for
all indoor unit
models)
Conrm
Timer
Day Off/
Delete
Copy/
Follow me
Mode
Back/Turbo
Swing Timer
Day o/Del
Conrm Back/Turbo
Copy/
Follow me
Mode
Fan speed
(Lock)
-+Increase

11
Setup
Set the Current Day and Time
1. Press and hold the Timer button for 3 sec-
onds.
2. Use the + and - buttons to select the day. The
selected day will ash.
3. Press the Timer button to complete the date
setting.
4. Use the + and - buttons to set the current time.
NOTE – the controller uses a 24-hour clock.
5. Press the Timer button to complete the time
setting.
Select Fahrenheit or Celsius for display
Press and hold the Back/Turbo button and the
Copy/Follow me button simultaneously for 3 sec-
onds to toggle between displaying degrees Fahr-
enheit or degrees Celsius.
To Set Room Temperature Sensor Location
Press the Copy/Follow me button to toggle be-
tween having the room temperature sensed by
the indoor unit or by the controller. NOTE - The
Follow me indicator will display on the screen
when the room temp is being sensed by the con-
troller.
Key Pad Tone (beep)
1. Press and hold the Swing button and the Tim-
er button simultaneously for 3 seconds to turn
off the key pad tone.
2. Press and hold the Swing button and the Tim-
er button simultaneously for 3 seconds again
to turn on the key pad tone.

12
To Start/Stop Operation
Press the Power button.
To set the operation mode
1.Press the Mode button to set the operation
mode.
2.Use the + and - buttons to scroll through the
mode selections.
• Auto – System will automatically switch be-
tween heating and cooling depending on the
temperature sensed.
• Cool – System operates in cooling mode.
• Dry – System removes humidity according
to preset conditions (fan speed and set point
temperature, not a humidistat sensor). Can-
not adjust fan speed.
• Heat – System operates in heating mode.
• Fan – Fan only, no heating or cooling.
To Set (or change) the Set point
Press the + and - buttons to set the setpoint.
NOTE - the set point range is 62-86°F (17-30°C).
To Set the Fan Speed
Pressthe Fan speed(Lock)button toscrollthrough
the fan speeds. Auto → Low → Med → High
To Set Child Lock Function
1. Press and hold the Fan speed (Lock) button
for 3 seconds to lock all of the controller but-
tons.
2. Press and hold the Fan speed (Lock) button
again for 3 seconds to unlock all of the but-
tons.
Operation
Turn ON/OFF Turbo Function
Press the Back/Turbo button to activate and de-
activate the turbo functionality.
• Cooling Mode - Turbo sets the indoor unit
fan speed to high for a factory-set period
of time.
Set Swing Function
Press the Swing button to adjust louver direction
and oscillation.
3. Press the Swing button to adjust the louver
position. Each press moves the louvers 6°.
4. Press and hold the Swing button for two sec-
onds to begin continuous louver oscillation.
The Swing icon displays on the screen. Swing
functionality not available for all indoor unit
types.
5. For cassette units only, adjust each
of the four louvers independently.
Press and hold the Swing button for
two seconds. The Swing icon will ash.
Press the increase or decrease buttons
to select the louver to adjust (the -0 setting
makes all louvers move at the same time).
After selecting the louver to adjust, press the
Swing button to adjust the louver angle. Each
press moves the louver 6°.

13
Timer and Schedules
Use the Timer button to setup Weekly schedules
or to setup timed operation for the indoor unit.
Timers are used to schedule On/Off operation
only. Schedules are used to change operational
settings for dened periods of time (events).
Setup Timed Operation Start Time
1. Press the Timer button until Day On is high-
lighted.
2. Press the Conrm button.
3. Use the + and - buttons to set the time to start
operation.
4. Press the Conrm button.
Setup Timed Operation Stop Time
1. Press the Timer button until Day Off is high-
lighted.
2. Press the Conrm button.
3. Use the + and - buttons to set the time to stop
operation.
4. Press the Conrm button.
Setup Timed Operation Start and Stop Time
1. Press the Timer button until Day On/Off is
highlighted.
2. Press the Conrm button.
3. Use the + and - buttons to set the time to start
operation.
4. Press the Conrm button
5. Use the + and - buttons to set the time to stop
operation.
6. Press the Conrm button.
Create Schedules (up to 8 events per day)
1. Press the Timer button until Week is high-
lighted.
2. Press the Conrm button.
3. Use the + and - buttons to select the day of the
week to setup the scheduled events.
4. Press the Conrm button.
5. Setup the rst event of the schedule.
Create and Setup Scheduled Events (up to 8
events per day)
1. After selecting the scheduled day.
2. Use the + and - buttons to set the start time of
the event. The display will show the event’s
start time, mode, set point and fan speed.
3. Press the Conrm button to conrm the start
time and move to the operation mode selec-
tion.
4. Use the + and - buttons to select the opera-
tion mode for the event.
5. Press the Conrm button to conrm the op-
eration mode and move to the set point se-
lection.
6. Use the + and - buttons to set the set point
for the event.
7. Press the Conrm button to conrm the set-
point and move to the fan speed selection.
Not available when operation mode is set to
Fan or Off.
8. Use the + and - buttons to select the fan
speed for the event.
9. Press the Conrm button to conrm the fan
speed and complete the settings for this
event. Not available when operation mode is

14
set to Auto, Dry or Off.
10. Follow steps 2 through 9 to setup the next
event. Each event ends at the start time of
the next event.
NOTE - Use the Back/Turbo button to return to
the previous step during event setup.
Activate and Deactivate Timed Operation
1. Press the Timer button to activate timed op-
eration.
2. Press the Power button to deactivate timed
operation.
Setup Days Off
Setup a day, or multiple days, within the sched-
uled week for which the indoor unit will not oper-
ate. When the day arrives, the unit will be pow-
ered off and will not operate until the next day’s
rst event. Once the set day has passed, the
Day Off setting is automatically removed.
1. Press the Timer button.
2. Press the Conrm button.
3. Use the + and - buttons to select the day of
the week.
4. Press the Day off/Del button.
5. Press the Back/Turbo button.
6. Follow steps 3 and 4 for every day off required.
Copy a Schedule to a New Day
All events for the scheduled day will be copied.
1. Press the Timer button until Week is high-
lighted.
2. Press the Conrm button.
3. Use the + and - buttons to select the day to
copy from.
4. Press the Copy/Follow Me button. The letters
“CY” will be displayed on the screen.
5. Use the + and - buttons to select the day to
copy to.
6. Press the Copy/Follow Me button to conrm.
7. Press the Back/Turbo button to return to the
weekly timer.
8. Follow steps 3 through 7 to copy a schedule
for additional days.
Edit a Scheduled Event
1. Press the Timer button until Week is high-
lighted.
2. Press the Conrm button.
3. Use the + and - buttons to select the day of
the week.
4. Press the Conrm button.
5. Use the + and - buttons to select the event to
edit. The display will show the event’s start
time, mode, set point and fan speed.
6. Use the + and - buttons to change the start
time of the event.
7. Press the Conrm button to conrm the start
time and move to the operation mode selec-
tion.
8. Use the + and - buttons to change the opera-
tion mode for the event.
9. Press the Conrm button to conrm the op-
eration mode and move to the set point se-
lection.
10. Use the + and - buttons to change the set
point for the event.

15
11. Press the Conrm button to conrm the set-
point and move to the fan speed selection.
Not available when operation mode is set to
Fan or Off.
12. Use the + and - buttons to change the fan
speed for the event.
13. Press the Conrm button to conrm the fan
speed and complete the changes for this
event. Not available when operation mode is
set to Auto, Dry or Off.
NOTE - Use the Back/Turbo button to return to
the previous step.
Delete an Event from a Scheduled Day
This action cannot be undone.
1. Press the Timer button until Week is high-
lighted.
2. Press the Conrm button.
3. Use the + and - buttons to select the day of
the week.
4. Press the Conrm button.
5. Use the + and - buttons to select the event to
delete. The display will show the event’s start
time, mode, set point and fan speed.
6. Press the Day off/Del button.

16
Troubleshooting Fault Codes
Programmable
Wired
Controller
Indoor Unit Error Codes Description
E1 Communication error between indoor unit and outdoor units
E2 Indoor room temperature sensor error (T1)
E3 Indoor coil temperature sensor error (T2)
E4 Indoor coil outlet temperature sensor error (T2B)
E5 Outdoor ambient temperature sensor error (T4)
E5 Outdoor coil temperature sensor error (T3)
E5 Compressor discharge temperature sensor error (T5)
E7 Indoor unit EEPROM error
E8 Indoor fan speed error (DC motor)
EA Outdoor current overload protection
Ed Outdoor unit EEPROM error
Ed Outdoor unit fan speed error (DC fan motor)
EE High water level alarm
EF Refrigerant leakage detection (Cooling mode only)
EF Outdoor IGBT temperature sensor error
F0 Communication error between wired controller and indoor unit
F1 The cassette panel is abnormal