MrCool PTAC 5 Series Operating instructions

Installation & Owner’s
Manual
Packaged Terminal
Air Conditioner/Heat Pump
PTAC**5 & PTHP**5
Due to updates and constantly improving performance, the information and instructions
within this manual are subject to change without notice. Please visit
www.mrcool.com/documentation to ensure you have the latest version of this manual.
Version Date: 06-25-21

Contents
Page 1 mrcool.com
DISCLAIMER: The images and illustrations used in this manual are for demonstration and
explanation purposes only. The actual shape and size of the unit and components therein may vary.
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1
2
3
4
5
6
7
8
WARNINGS .................................................................................................................
CAUTIONS .............................................................................................................
Operation of Current Detection Device .............................................................
Air Conditioner Features .........................................................................................
Control Panel Operation ......................................................................................
DIP Switch Configuration (Optional) ...................................................................
DIP Switch Configuration by Panel Control (Optional) ........................................
Wall Thermostat Terminal (Optional) .................................................................
Installation .............................................................................................................
Care & Cleaning .....................................................................................................
Troubleshooting ....................................................................................................
2
4
5
6
7
9
11
12
14
16
18

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Read This Manual Before Using
Incorrect usage may cause serious damage or injury.
CAUTION
WARNING
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Safety Precautions
The symbols below are used throughout this manual to indicate instructions that should be followed
closely or actions that should be avoided to prevent death, injury, and/or property damage. Inside
this manual, you will also find helpful hints on how to use and maintain your air conditioner properly.
Performing a little preventative care on your part can save you a great deal of time and expense over the
the life of the air conditioner. Many of the answers to common problems can be found in the
charts contained in troubleshooting section. If a problem or issue arises, reviewing the troubleshooting
section first may make calling a service provider unnecessary.
This symbol indicates ignoring instructions may cause bodily injury, damage
to the unit, or other surrounding property.
This symbol indicates ignoring instructions may cause death or serious injury.
This symbol indicates that you should NEVER perform the indicated action.
WARNING
Always ensure the power plug is plugged into the outlet properly. If not, it could cause electric
shock or fire due to excess heat generation.
Always ensure the unit has been effectively grounded. Incorrect grounding could cause electric
shock.
Always install the unit with a circuit breaker and a dedicated power circuit. Incorrect installation
may cause fire or electric shock.
If the unit begins to emit strange sounds, smells, or smoke, unplug it immediately. If not, it could
cause fire and/or electric shock.
Always keep firearms away from the unit, as these could cause fire.
Always ventilate the room before operating the air conditioner should there be a gas leak from
another appliance. Failure to do this could cause an explosion, fire, and/or burns.
DO NOT operate or stop the unit by inserting or removing the power cord plug from the outlet.
This could cause electric shock and/or fire due to heat generation.
DO NOT modify the length of the power cord, or share the outlet with other appliances. This could
cause electric shock and/or fire due to heat generation.
DO NOT operate this unit with wet hands or in a damp environment. This could cause electric
shock.
DO NOT allow water to come into contact with electrical components of the unit. It could cause
failure of the machine and/or electric shock.
DO NOT use the socket if it is damaged or loose. It could cause fire and/or electric shock.
DO NOT open the unit while it is operating. It could cause electric shock.
DO NOT disassemble or modify the unit. It could cause electric shock.
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Safety Precautions
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WARNING
DO NOT direct airflow from the unit directly at occupants in the room. This could be hazardous to
their health.
DO NOT use the power cord close to any heating appliances. It could cause fire and/or electric
shock.
DO NOT use the power cord near flammable gas or combustibles, such as gasoline, benzene,
thinner, etc. It could cause an explosion and/or fire.
FOR YOUR SAFETY
DO NOT store or use gasoline , or any other materials or liquids which may contain flammable
vapors in the vicinity of this appliance or any other.
DO NOT use an extension cord or an adapter plug, as this could cause a fire hazard and/or electric
shock.
DO NOT remove any of the prongs from the power cord.
ELECTRICAL INFORMATION
Ensure the electrical service is adequate for the model you have chosen. This information can be
found on the serial plate located on the side of the cabinet and behind the grille.
Ensure the air conditioner is properly grounded. Proper grounding is necessary in order to
minimize and avoid electrical shock and/or fire hazards. The power cord of this unit is equipped
with a three-pronged grounding plug to protect against electrical shock hazards.
The wall receptacle used for this unit must also be properly grounded. If the wall receptacle
intended to be used is not adequately grounded, or protected by a time delay fuse or circuit
breaker, have a qualified electrician install one.
Ensure the receptacle is still accessible after the unit is installed.
The appliance should be installed in accordance with national and local wiring regulations.
DO NOT run the air conditioner without the side protective cover in place. Otherwise, it could
result in mechanical damage within the unit.
DO NOT use an extension cord or an adapter plug.
NOTE: The power supply cord used on this air
conditioner contains a current detection device that is
designed to reduce the risk of fire. Please refer to the
Operation of Current Device later in this section of the
manual for further details. In the event that the power
supply cord becomes damaged, it cannot be repaired.
It must be replaced with a cord from the product
manufacturer. The illustration below represents
different types of power cords (dependent on model).
Power
Cord
Power
Supply
230V
15A
230V
20A
230V
30A
265V
15A
265V
20A
265V
30A
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Safety Precautions
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CAUTION
This appliance is not intended for use by individuals, and children under the age of 8 years old,
with reduced physical, sensory, or mental capabilities. It is also not intended for use by individuals
with a lack of experience or knowledge, unless they have been given supervision or instruction
concerning use of the appliance by a person responsible for their safety. Children should be
supervised at all times to ensure that they do not play with the appliance. Cleaning and user
maintenance should not be performed by children.
If the power cord is damaged, it must be replaced by the manufacturer, its service agent or a
similarly qualified individual in order to avoid a hazard.
The appliance should be installed in accordance with national wiring regulations.
The appliance equipped with an electric heater should have at least 3.3 ft (1 m) of distance from
combustible materials.
Contact an authorized service technician to perform repairs or maintenance of this unit.
Contact an authorized installer for the installation of this unit.
Should there be any differences between the User’s Manual and Remote Controller illustration
regarding function description, the User’s Manual should take precedence.
If the air conditioner is knocked over during use, turn off the unit, and unplug it from the main
power supply immediately. Then, visually inspect the unit to ensure there is no damage. If you
suspect the unit has been damaged, contact a qualified technician or customer service for
assistance.
Turn off power to the machine during a thunderstorm to avoid damage to the unit from lightning.
To reduce the risk of fire or electric shock, do not use this fan with any solid-state speed control
device.
Ensure the room the unit is operating in is well ventilated if used in a room with a stove. If not, it
may cause an oxygen shortage.
Route power cord away from any traffic areas to ensure it will not be tripped over.
Always hold the plug by the head when unplugging it from an outlet.
Always turn off the main power switch when not using the unit for an extended period of time. If
not, it could cause failure of the product or fire.
Always ensure that the mounting bracket is not damaged due to prolonged exposure. If the
bracket is damaged, it could cause it to weaken or fail which could result in the unit falling.
Always insert the air filters securely. They should be cleaned once every two weeks.
Use caution when unpacking and installing the unit. It may have sharp edges which could cause
injury.
The evaporator should be cleaned every three months by a qualified professional. If this is not
done, it could cause failure of electric heating function.
If water enters the unit, turn the unit off at the power outlet and switch off the circuit breaker.
Isolate the unit by unplugging the power cord from the outlet and then contact a qualified service
technician.
DO NOT operate the unit without filters. This could cause unit failure.
DO NOT operate the unit in a room where it could be exposed to excessive amounts of water such
as a bathroom or laundry room.
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Safety Precautions
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DO NOT run the power cord under carpeting, throw rugs, runners, or similar items.
DO NOT run the power cord under furniture or appliances.
DO NOT place heavy objects on the power cord and ensure it is not compressed. This could
cause a fire and/or electric shock.
DO NOT touch the metal parts of the unit when removing the air filter as this could cause injury.
DO NOT clean the unit with water. Water can enter the unit and not only cause electric shock but
also degrade the insulation.
DO NOT attempt to clean the unit while the power is on, as it could cause fire and/or electric
shock. When the unit is to be cleaned, turn the power off and turn off the circuit breaker.
DO NOT allow pets or house plants to be exposed to the direct airflow from the unit, as this could
cause injury to them.
DO NOT use this air conditioner for special purposes such as to preserve precision devices, food,
plants, or art. It could cause deterioration of the quality of these items.
DO NOT operate this unit during a storm or hurricane. Stop operation and close any windows.
Operating this air conditioner during a storm with the windows open can result in saturation of
the indoor rooms and furnishings with water.
DO NOT place obstacles around the air inlets or inside of the air outlet. It could cause failure of
the appliance or cause an accident.
DO NOT use strong detergent such as wax or thinner as these could deteriorate the appearance
of the unit by changing the color or scratching the surface. Only use a soft cloth to wipe the unit
clean.
DO NOT drink water drained from the air conditioner, as it contains contaminants which could
make you sick.
CAUTION
OPERATION OF CURRENT DETECTION DEVICE (optional)
The power supply cord of this device contains a current detection device that is designed to sense
damage to the power cord. To test this function, please follow these steps:
1. Plug in the air conditioner
2. The head of the power cord will have TWO buttons, TEST and RESET. Press the
TEST button and you will hear a click as the RESET button pops out.
3. Press the RESET button and you will hear a click as the button engages back
into the head of the plug.
4. The power cord is now supplying electricity to the unit.
NOTE: On some products this will also be indicated by a light on the plug head.
Always ensure the reset button is pushed in and engaged for correct operation.
The power supply must be replaced if it fails to reset when either the TEST button is pushed, or it
cannot be reset. A new power supply can be obtained from the product manufacturer.
If the power cord is damaged, it cannot be repaired. It must be replaced by one obtained from the
product manufacturer.
When 265V units are installed, the power supply must be a part of permanent wiring. Permanent
wiring may be done through the accessory sub-base. An exposed cord connection on 265V units is
not permitted.
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Air Conditioner Features
Page 6
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1
This unit has many features that the service technician must be familiar with in order to properly service
the unit.
Compressor Restart Delay
This feature extends the overall life of the
compressor by preventing short-cycling of the
air conditioner. When the compressor restarts,
the unit is designed to give a minimum of 3
minutes in order to allow enough time for
refrigerant pressures to equalize for optimized
cycling.
Memory
The unit has a memory function to restore
settings after a loss of power. Should there be
a power outage, or a loss of power, the system
is designed to remember all of the previous
control settings (mode, fan speed, on/off, and
the configuration). Once power is restored,
the unit will restart with the settings and in the
mode that was selected at the time the power
was lost.
Automatic Evaporator Freeze Protection
When the temperature of the evaporator
reaches a level that is too low, this function
engages automatically to prevent the
evaporator from freezing. It accomplishes this
by turning the compressor off and turning
the fan on. Once the evaporator temperature
reaches a safe level, this function will
automatically turn off.
Automatic Quick Warm-up (for heat pump
models only)
This function turns on when the room
temperature falls to 8°F (4.5°C) below set
temperature of the unit. During this process,
the reverse cycle heat is shut off and the
electric heat strip is turned on for one cycle
until heating is satisfied.
LED Indicators and Buttons
The touch pad of the unit has buttons to
control the MODE, FAN, and directional arrows
to increase and decrease the set-point of the
temperature. The unit is also equipped with
LED indicators that correspond to the MODE,
FAN SPEED, and TEMPERATURE SET-POINT
to indicate the status of the unit. The unit has
LEDs to indicate which speed the fan is set to,
HIGH, MEDIUM, and LOW. There are also LED
indicators for FAN, COOL, and HEAT to indicate
which of the operating modes is currently
selected. There is also an LED indicator for the
POWER setting. If the unit is ON the LED will
illuminate green. If the unit is OFF, the LED will
also be off. NOTE: HEAT Mode is for Cooling &
Heating models only.
High Temperature Protection while
operating in Heat Mode
The compressor and/or electric heater will
automatically shut off if the system senses
the temperature of the indoor airflow from
the unit is too high. It will also shut-off if the
system senses there is an error with the indoor
temperature sensor
Temperature Unit Display Configuration (°F
or °C)
The display of the unit can be set to display the
temperature in either Fahrenheit or Celsius.

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Control Panel Operation 2
Control Panel Keypad
The control panel keypad will look similar to
the illustration in Fig 2.1. This will be used to
control most, if not all, of the functions of the
unit. NOTE: some models may be equipped
with a REMOTE SIGNAL RECEPTOR. If this
is the case, the unit can be controlled with
the control panel keypad or by the remote
control.
Power
Press the POWER button to turn the unit on or
off.
Mode
Push this button to cycle through and select
the desired mode: COOL, HEAT, or FAN. The
indicator light beside the mode selected will
illuminate.
COOL: In this mode, cooling will begin
automatically when the room temperature
is 4°F (2°C) below the set temperature. The
compressor will run for at least 5 minutes in
this mode before stopping.
HEAT: In this mode, the temperature can be
set to a maximum of 84°F (29°C). For heat
pump models, the unit will alternate between
reverse cycle heat mode and electric heater
mode depending upon the difference
between the temperature the unit is set to
and the room temperature. The fan motor
will cycles with the compressor.
FAN: The fan operates without heating or
cooling activated (Fan-Only mode). NOTE: If
the unit features DIP SWITCHES, these can
be used to set the temperature range.
Please see the DIP Switch Configurations
section for further information.
NOTE
The reverse cycle and electric heater cannot
be run at the same time. In the scenarios
listed below, it is normal that the unit does
not operate in reverse cycle mode:
1. When the outdoor temperature is lower
than 40°F (4°C) or the room temperature
falls to 8°F (4.5°C) below the set
temperature of the unit, reverse cycle
mode will not occur.
2. There is a 3 minute minimum compressor
run time at any setting to prevent it from
short-cycling. The indoor fan motor will
start before the compressor and stop after
the compressor has cycled off.
3. Pushing the “S1” on the DIP SWITCHES to
the UP (ON) position will prevent the unit
from operating in reverse cycle mode .
4. When frost builds up on the evaporator
coils, the unit will automatically defrost
and the compressor will cycle off.
Up/Down Buttons (+/-)
Push the UP or DOWN buttons to increase or
decrease the temperature setting of the unit
in cooling or heating mode. The temperature
can be adjusted in increments of 1°F (1°C) with
each press of the button. The set temperature
will show on the unit display. NOTE: Pressing
and holding the + and - buttons together will
alternate the temperature display between
°F and °C.
SPEED (Fan Speed)
Every push of this button will change the fan
speed setting to either HIGH, MEDIUM, and
LOW.
Constant Fan Mode
In cooling mode, press the button to turn
the constant fan setting on or off. When this
function is turned on, the constant fan light will
illuminate. This indicates the fan is continuously
running for cooling. When this function is
turned off, the constant fan light will no longer
be illuminated, and the fan will go back to
cycling with the compressor.
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Fig. 2.1

Control Panel Operation
Page 8mrcool.com
Displays
The display panel on the unit will show the
set temperature in either °F or °C. While in
Fan-Only Mode, the display will show the room
temperature.
Control Codes (on some models):
LC - Keypad on the control panel is not
available. The unit can only be set using the
wire controller.
FC - Keypads on the control panel and wire
controller are not available. The unit can only
be set by using the Front Desk Control only.
Error Codes:
AS - Room temperature sensor error;
ES - Evaporator temperature sensor error;
CS - Condenser temperature sensor error;
OS - Outside temperature sensor error;
HS - Exhaust temperature sensor error;
LE - Wire controller error;
NOTE: When an error occurs, unplug the unit
and plug it back in. If the error repeats, call a
service professional.
Other Codes:
LO - Room temperature is lower than 32°F
(0°C);
HI - Room temperature is higher than 99°F
(37°C);
FP - Low temperature protection;
Unit Operating Temperature Ranges
* Outdoor temperature range for special
tropical models 64°F-125°F (18°C-52°C) .
NOTE: This air conditioner is designed to be
operated in the temperature ranges listed
in the table above. If the unit is operated
outside of these temperature ranges,
performance could be reduced.
Accessory
NOTE: When the unit displays LC, the keypad
on the control panel may not available. The
unit can be set by using the wire controller
only. You can install the controller on the
control panel.
NOTE: For some models, there may be a
3 second delay after pressing any button
before the selected operation will occur.
NOTE: When there are wide differences
between the User’s Manual and Remote
Controller Illustration when describing
the functions, what is written in the User’s
Manual will take precedence.
NOTE: All illustrations contained in
this manual are for demonstration and
explanation purposes only. Your actual
unit may vary in shape, size, and general
appearance.
Cooling
Operation
Heating
Operation
Outdoor
Temperature*
Indoor
Temperature
Outdoor
Temperature
Indoor
Temperature
64°F - 109°F
(18°C - 43°C)
62°F - 90°F
(17°C - 32°C)
23°F - 76°F
(-5°C - 24°C)
32°F - 80°F
(0°C - 27°C)
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THIS UNIT IS CONTROLLED BY A WALL MOUNTED THERMOSTAT

DIP Switch Configuration (Optional) 3
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Remove the Front Panel
The DIP switch controls are located behind
the front panel through an opening that is
beneath the control panel. To gain access to
this, the front panel will need to be removed.
Please refer to Fig. 3.1 for the proper
procedure of removing the front panel.
The DIP switches are accessible without
opening the control box. Please refer to
Fig. 3.2.
Always make sure the unit is powered off
before making adjustments to the DIP
switches.
DIP Swtiches Configuration
Refer to Table 1 and Fig. 3.3 for the DIP
Switches configurations and the functions of
each DIP switch.
2
1
1. Pull the front panel out from the bottom to
release it from the tabs.
2. Then lift the panel upward.
Fig. 3.1
Fig. 3.2
Fig. 3.3
No.
S1
S2
S3
S4 & S5
S6
S7
S8
S9 (with
S3 Up)
S9 (with
S3 Down)
Sw11
Electric Heat Only Electric Heat and Heat Pump
Up Position (ON) Down Position (OFF) Remarks
For Heat Pump unit only
Temperature Display in °F
Wall Thermostat Enabled
Up & Up: 61°F - 86°F (16°C - 30°C)
Up & Down: 65°F - 78°F (18°C - 26°C)
Down & Up: 63°F - 80°F (17°C - 27°C)
Down & Down: 68°F - 75°F (20°C - 24°C)
Control Panel Enabled
Temperature Display in °C
The setting of two switches
(S4 & S5) combine to select
temperature range of unit
Continuous Fan Operation for
Heating
Continuous Fan Operation for
Cooling
Fan Cycle for Heating
Fan Cycle for Cooling
Low Temp. Protection Enabled
To use some types of Wall
Thermostat
Use Control Panel Only
Load Delay for 3 seconds
To use PTAC or other wall
thermostat
To use Control Panel or some
types of wall thermostat
Normal
Consult with retailer or
manufacturer for details
Use control Panel or types of
wall thermostat, the other
one must be turned off
Optional
Low Temp. Protection Disabled Optional
Table 1 - DIP Switch Configurations
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DIP Switch Configuration
Page 10mrcool.com
NOTE: On Heating Mode, the temperature
cannot be set higher than 84°F (29°C).
Enable Wall Thermostat
A wired wall thermostat can be connected to
the unit. If this is the case, the corresponding
dip switch (Refer to Table 1) must be switched
to the position to enable the Wall Thermostat
before it can begin controlling the unit.
Low Temperature Protection (optional)
If the unit that the room temperature is below
32°F (0°C), the fan motor and electric heat
strip will activate and warm the room to a
temperature of 40°F (4.4°C). Shortly after this
temperature has been reached, the fan will
stop.
Electric Heat Only (for heat pump units only)
This setting is typically used for emergency
heating.
Heat and Cool Fan CON/CYC DIP-switches
These switches allow the fan to either operate
continuously or in cycle mode while the unit is
operating in heating or cooling mode.
CON (Continuous)
Enables the fan to run continuously allowing
air to circulate even after the set temperature
has been reached. This switch helps to
maintain the room temperature closer to the
set temperature on the unit.
CYC (Cycle)
This setting enables the fan to cycle on and
off with the compressor or electric heater.
The fan will stop a short time after the set
temperature has been reached.
Temperature Set-Point Limits
Enables a restricted rang of temperature
control.
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DIP Switch Configuration by
Panel Control (Optional) 4
Page 11 mrcool.com
DIP Switch Configuration by Panel Control
Turn off the unit.
Press the up (+) and down (-) buttons together for 3 seconds
to activate the DIP switch configurations on the control panel.
Refer to Fig 4.1.
Refer to Table 1 below for the control panel DIP switch
configurations and functions. NOTE: Press the up (+) and down
(-) buttons together for 3 seconds again (or do not complete
any further operations for 30 seconds) to exit the DIP switch
configuration and the unit will save the last settings
entered.
Display function settings, with 2 digits in the LED display
window. The first digit will represent the high (left) for DIP
switches. The second digit will represent the low (right) for
functions. Please refer to Fig. 4.1 and the table below.
Press the up (+) button to set the dip switches, press the
down (-) button to set the functions.
Fig. 4.1
No. High
(left)
S1
/0
1
2
S2
S3 & S9 3
4
6
7
8
A
B
S4 & S5
S6
S7
S8
SW7
Sw11
1 - Electric Heat Only
1 - by Control Panel 0 - by DIP switches
0 - Electric Heat and Heat Pump
Low (right) Remarks
For Heat Pump units only
1 - Temperature Display in °F
4 - 62°F - 86°F (17°C - 30°C)
3 - 61°F - 86°F (16°C - 30°C)
2 - 65°F - 78°F (18°C - 26°C)
1 - 63°F - 80°F (17°C - 27°C)
0 - 68°F - 75°F (20°C - 24°C)
3- Use Control Panel or Some Types of Wall Thermostat;
2- Use Some Types of Wall Thermostat;
1- Use PTAC or Other Wall Thermostat;
0- Enable Control Panel
0 - Temperature Display in °C
Consult with the retailer
or manufacturer for
details
1 - Continuous Fan
Operation for Heating
1 - Continuous Fan
Operation for Cooling
0 - Fan Cycle for Heating
0 - Fan Cycle for Cooling
1 - Low Temperature
Protection Enabled
1 - Front Desk Control
Disabled
0 - Front Desk Control
Enabled
1 - Load Delay for
3 seconds
0 - Normal
Optional
Optional
0 - Low Temp. Protection Disabled Optional
Not available for use
PTAC other wall
thermostat
Table 1 - DIP Switch Configurations by Control Panel
NOTES:
1. The LED display window will show “00” when you first enter the setting mode, only when you set “01” can you move
onto the next setting.
2. To activate front desk control function, you need to flip the SW7 dip switch in the down (off) position, and then set the
panel control to “A0.”
3. After all the settings have been set, press the up (+) and down (-) buttons together for 3 seconds to exit the operation
interface and turn off the power. Once power is turned back on, the settings will be activated.
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For Heat Pump units only
Wall Thermostat Terminal (Optional) 5
Page 12
Only trained, qualified personnel should access
the electrical panel on the unit and install
electrical accessories. Please contact your local
electrical contractor, dealer, or distributor for
assistance.
Thermostat Wire Routing
Thermostat wire is field supplied. Recommended wire
gauge is 18 to 20 gauge solid thermostat wire. NOTE:
It is recommended that extra wires are run to the
unit in case any are damaged during installation.
The thermostat wire should always be routed
around or under, NEVER through the wall sleeve.
The wire should then be routed behind the front
panel to the easily accessible terminal connector.
Please refer to Fig. 5.1.
NOTE: Refer to the thermostat installation
instructions for further details installing the
wall thermostat.
Installation instructions of some types of wall
thermostats (it may be necessary to consult with
the retailer or manufacturer for details.)
Pull the DIP switch to the Down (Off) position
as shown in Fig. 5.2.
mrcool.com
Fig. 5.1
Insert the wire connector of the wall
thermostat into the corresponding terminal
as shown below. The correct terminal to use
is dependent upon the shape of the wall
thermostat connector. Refer to Fig. 5.3.
Installation Instructions of PTAC other Wall
Thermostat
Remove the two screws and take the cover
panel down, as shown in Fig. 5.4 below. Refer
to Fig. 5.5 on the next page for the terminal
diagrams.
IMPORTANT
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Fig. 5.2
Fig. 5.3
Fig. 5.4

CAUTION
Wall Thermostat Terminal (Optional)
Page 13 mrcool.com
Unit damage or improper operation could occur if the points listed in this caution are not followed.
Improper wiring could damage unit electronics. Common busing is not permitted. Damage or erratic
operation may result.
Only use 4-way terminal for heat pump connection only.
It is recommended to set the compressor protection time for more than 3 minutes on the wall
thermostat. If it is set for less than 3 minutes, the compressor will still delay restart for 3 minutes.
Wall thermostat must have a 4-way valve for heating change-over.
For thermostats that have only one fan speed output (on or auto), the fan speed is determined by
how the terminal connector is wired. If low fan speed is desired, wire the G output from the
thermostat to (LOW-FAN) on the unit’s terminal block. If high fan speed is desired, wire the G output
from the thermostat to (HI-FAN) on the unit’s terminal block.
The temperature range of the wall thermostat must correspond with the DIP switch setting of the
unit.
The wall thermostat must be of a type that is compatible with the unit type: heat pump or no heat
pump.
If the wall thermostat has only one electrical heater output, connect the two terminals of HEAT 1
and HEAT 2. The unit can operate two electrical heaters (if the unit has two electrical heaters).
DO NOT remove the control panel.
Front Desk Control
The controller can handle a switch signal from
FC(L) and FC(N) input, referred to as front desk
control. The input must be 24VAC. If the system
does not receive a 24VAC signal, it will turn
off. Otherwise, the unit will run under normal
control.
The DIP switch can control the FRONT DESK
CONTROL feature. If the DIP switch is in
the DOWN position, the unit will be turned
off, otherwise, the unit will run under normal
control. Refer to Fig. 5.6 below.
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Fig. 5.5
Fig. 5.6

CAUTION
Installation 6
Page 14mrcool.com
Installation Preparation and Overview
If using an existing sleeve, you should measure
the wall sleeve dimensions.
Install the new air conditioner according to these
installation instructions to achieve the best
performance.
All wall sleeves used to mount the new air
conditioner must be in good structural condition. It
must also have a rear grille that securely attaches to
the sleeve, or the flange of the sleeve, in order to
secure the new air conditioner.
To avoid vibration and noise, ensure the unit is
installed securely and firmly.
When installing the sleeve, ensure there are no
objects or obstructions within 20 in (508 mm) of the
rear of the unit that could interfere with heat
radiation and exhaust airflow.
Preparation of Sleeve Assembly
Refer to the installation instructions of the sleeve
assembly for further details.
Preparation or Rear Grille Assembly (optional)
Refer to the installation instructions of the rear grille
assembly for further details.
Unit Installation
1. Carefully remove shipping tape from the front panel.
Please refer to Fig. 6.1.
2. Then, remove the front panel. Please refer to Fig. 6.2.
3. Remove the shipping screw from the vent door.
Please refer to Fig. 6.3.
Dimensions of Air Conditioner Unit
Dimensions of Assembly Sleeve (optional)
42 in (1067 mm)
16 in (408 mm)
23.9 in (606 mm)
42 in (1067 mm)
16 in (408 mm)
14.8 in (376 mm)
2
1
Steps To Remove Front Panel
1. Pull the front panel out from the bottom to
release it from the tabs.
2. Then lift the panel upward.
Fig. 6.2
Fig. 6.1
Fig. 6.3
Use caution when picking up or moving the unit as
there are sharp edges that can cause injury.
Use two people when lifting the air conditioner as
it is heavy.
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CAUTION
Unit Installation
Page 15 mrcool.com
Unit Installation (Continued)
5. Rotate the vent control lever to open or close the
vent door.
NOTE: When the vent control lever is set to CLOSE,
only the air inside the room is circulated and
filtered. When it is set to OPEN, some outdoor air
will be drawn into the room. This will reduce the
heating and cooling efficiency.
6. Lift the unit until it is level and slide it into the
wall sleeve until it is firmly against the front of the
wall sleeve. Then, secure it with 4 screws and
washers (supplied with the sleeve assembly) through
the unit flange holes. Refer to Fig. 6.4 and Fig. 6.5.
7. Using the image below as a guide, reinstall the
front panel by first placing the tabs of the panel over
the top rail of the unit. Second, push inward at the
bottom of the panel until it snaps into place.
Please refer to Fig. 6.6.
DO NOT put obstacles around the air-inlet
or inside of the air outlet of the unit (such
as a window curtain, etc.).
Always insert the filter securely.
Be sure to clean the filter once every two
weeks as required.
1
2
Fig. 6.4
Fig. 6.5
Fig. 6.6
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CAUTION
Care and Cleaning 7
Page 16mrcool.com
Front Panel and Case
To clean the front panel and case, first turn off
the power to the unit and disconnect the power
supply. Only use water and a mild detergent to
clean the unit. DO NOT use bleach or abrasives.
Some commercial cleaners could damage the
plastic parts of the unit.
Outdoor Coil
The coil located on the outdoor side of the unit
should be checked regularly. The unit will need
to be removed in order to inspect the dirt build
up that will occur on the inside of the coil. If
the coil is clogged with dirt and soil, it should
be professionally cleaned. The inside and
outside of the outdoor coils should be cleaned
on a regular basis. NOTE: Never use a high
pressure spray on the coil, as it could cause
damage.
Air FIlters
Ensure the unit is turned off before attempting
to clean the filters. Cleaning the air filters is the
most important maintenance you can do to
maintain unit efficiency. Clogged air filters will
reduce cooling, heating, and airflow. Clean the
filters once every two weeks. Cleaning the filters
regularly will offer the following benefits:
Decrease the cost of operation
Save energy
Prevent indoor coil from clogging
Reduce the risk of premature component
failure
To clean the air filters follow the steps below
and refer to Fig. 7.1 and Fig. 7.2:
1. Remove the two air filters, by pulling
up on the top of each filter located on the
front panel of the unit.
2. Vacuum any heavy soil that has
accumulated on the filters.
3. Run water through the filters.
4. Dry the filters thoroughly before replacing.
5. To replace the air filters, insert each filter
back into their respective slots on the front
panel and push down until it slides back into
place.
Removing the Air Filter
Replacing the Air Filter
Fig. 7.1
Fig. 7.2
Failure to read and follow these cautions
could result in equipment damage or
improper operation.
Any airflow restrictions could cause
damage to the unit.
DO NOT operate the unit without the
filters installed. If a filter becomes torn or
damaged it should be replaced
immediately. Operating the unit without
filters installed, or with a damaged filter,
will allow dirt and dust to reach the indoor
coil and reduce cooling, heating, airflow,
and efficiency.
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Care and Cleaning
Page 17 mrcool.com
Vent Door Filter
Ensure that the unit is off before attempting to
clean the vent door filter. If the vent door is open,
access requires the removal of the unit from the
wall sleeve. Clean the filter twice a year, or as
required.
To clean the filter follow the steps below and refer
to Fig. 6.3 (in section 6) and Fig. 7.3:
1. Ensure the shipping screw has been
removed from the vent door. Refer to Fig. 6.3.
2. Rotate the vent control lever to open the
vent door.
3. Remove the four screws from the vent
door filter.
4. First, pull out the vent door steel wire from
the hole of the vent door. Then, take off the
vent door and filter.
5. Clean the filter and dry it thoroughly before
reinstalling it.
6. Reinstall the vent door, filter, and four
screws.
7. Then, reinstall the vent door steel wire into
the hole of the vent door.
Fig. 7.3

Troubleshooting 8
Page 18mrcool.com
Possible Cause Solutions
UNIT DOES NOT START
Unit may have become unplugged.
Fuse may have blown.
Circuit breaker may have been tripped.
Unit may be turned off.
Unit may be in a protection mode.
Check that the plug is plugged securely into the outlet.
NOTE: The plug has a test /reset button on it. Ensure
that the plug has not been tripped.
Replace the fuse (see note 1 below).
Reset circuit breaker (see note 1 below).
Turn the unit on (bottom right button on the keypad).
UNIT IS NOT COOLING OR HEATING THE
ROOM
Unit air discharge section is blocked.
Temperature setting is not high or low
enough. NOTE: Temperature Set-point
limits may not allow the unit to heat or
cool the room to the desired temperature.
Refer to the DIP switch configuration
section of the manual.
Unit air filters are dirty or clogged.
Room is excessively hot or cold when the unit
is started.
Vent door has been left opened.
Unit could be in protection mode.
Compressor is in time delay.
Ensure that curtains, blinds, or furniture are not
restricting or blocking unit airflow.
Reset the temperature to a higher or lower setting.
Remove and clean air filters.
Allow for a sufficient time period for the unit to heat or
cool the room. Start heating or cooling the room earlier
before the outdoor temperature, heat from cooking, or
people gathering change the room temperature.
Close the vent door.
Check DIP switch and wall thermostat settings for desired
temperature range.
Wait 3 minutes for the compressor to restart.
DISPLAY IS SHOWING STRANGE NUMBERS OR
CHARACTERS ON IT
The unit could be in protection mode.
The unit may be set for °C, instead of °F.
UNIT MAKING NOISES
WATER DRIPPING FROM THE UNIT OUTSIDE
Clicking, gurgling, and whooshing noises are normal
during operation of the unit.
If a drain kit has not been installed, condensation
runoff during extremely hot and humid weather is
normal (See note 2 below).
If a drain kit has been installed, and is connected to a
drain system, check the gaskets and fittings around the
drain for leaks and clogs.
WATER DRIPPING INSIDE
Wall sleeve has not been installed level.
Wall sleeve must be installed level for proper drainage of
condensation. Check that the sleeve has been installed
level. If it has not been, make any necessary
adjustments.
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NOTES:
1. If the circuit breaker is tripped, or a fuse has blown, more than once, please contact a qualified electrician.
2. If the unit has been installed where condensation could drip in an undesirable location, an accessory drain kit should be
installed and connected to the drain system.
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Troubleshooting
Page 19 mrcool.com
Possible Cause Solutions
ICE OR FROST FORMS ON INDOOR
COIL
Low outdoor temperature.
Dirty or clogged filters.
When the outdoor temperature is approximately 55°F
(12.8°C) or below, frost could form on the indoor coil
when the unit is operating in COOLING mode. Switch the
unit to FAN operation until the ice or frost melts.
Remove and clean filters.
COMPRESSOR PROTECTION
Power may have cycled, so compressor is in
restart protection.
Random Compressor Restart - Whenever the unit is
plugged in, or power has been restarted, a random
compressor restart will occur. After a power outage, the
compressor will restart after approximately 3 minutes.
Compressor Protection - To prevent short-cycling of the
compressor, there is a random start-up delay of 3
minutes and a minimum compressor run time of 3
minutes.
ELECTRIC HEATING FAILURE Clean the evaporator once every 3 months by a qualified
technician or professional.
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