Daikin RXQ25AMV1B User manual

Service manual
Split Sensira R32 BBOP
RXQ25AMV1B
RXQ35AMV1B
ARXQ25AMV1B
ARXQ35AMV1B
FTXQ25AMV1B
FTXQ35AMV1B
ATXQ25AMV1B
ATXQ35AMV1B

Disclaimer
Service manual
2
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
Disclaimer
The present publication is drawn up by way of information only and does not constitute an offer binding upon
Daikin Europe N.V.. Daikin Europe N.V. has compiled the content of this publication to the best of its knowledge.
No express or implied warranty is given for the completeness, accuracy, reliability or fitness for particular purpose
of its content and the products and services presented therein. Specifications are subject to change without prior
notice. Daikin Europe N.V. explicitly rejects any liability for any direct or indirect damage, in the broadest sense,
arising from or related to the use and/or interpretation of this publication. All content is copyrighted by Daikin
Europe N.V..

Version log
Service manual
3
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
Version log
Version code Description Date
ESIE21-16 Document release February 2022

Table of contents
Service manual
4
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
Table of contents
1 Safety precautions 6
1.1 Meaning of warnings and symbols................................................................................................................................. 6
1.2 Dangers ........................................................................................................................................................................... 7
1.3 Warnings ......................................................................................................................................................................... 7
1.4 Cautions .......................................................................................................................................................................... 13
1.5 Notices ............................................................................................................................................................................ 13
2 Troubleshooting 14
2.1 To display the error code on the user interface ............................................................................................................ 14
2.2 To reset the error code via remote controller ............................................................................................................... 14
2.3 To reset the error code via outdoor unit ....................................................................................................................... 14
2.4 To perform a test run...................................................................................................................................................... 14
2.4.1 To perform a test run in winter season ......................................................................................................... 15
2.5 Error based troubleshooting........................................................................................................................................... 15
2.5.1 A1-00 – PCB abnormality ............................................................................................................................... 15
2.5.2 A5-00 – Outdoor unit: High pressure peak cut / freeze protection problem ............................................... 16
2.5.3 A6-00 – Indoor unit fan motor abnormality .................................................................................................. 17
2.5.4 C4-00 – Heat exchanger temperature sensor problem................................................................................. 17
2.5.5 C9-00 – Room thermistor abnormality.......................................................................................................... 18
2.5.6 E1-00 – Outdoor unit: PCB defect.................................................................................................................. 18
2.5.7 E5-00 – Outdoor unit: Overheat of inverter compressor motor................................................................... 19
2.5.8 E6-00 – Outdoor unit: Compressor startup defect........................................................................................ 20
2.5.9 E7-00 – Outdoor unit: Malfunction of outdoor unit fan motor .................................................................... 21
2.5.10 E8-00 – Outdoor unit: Power input overvoltage ........................................................................................... 21
2.5.11 EA-00 – Outdoor unit: Cool/heat switchover problem ................................................................................. 22
2.5.12 F3-00 – Outdoor unit: Malfunction of discharge pipe temperature............................................................. 23
2.5.13 F6-00 – Outdoor unit: Abnormal high pressure in cooling............................................................................ 24
2.5.14 F8-00 – System shutdown due to compressor internal temperature abnormality...................................... 25
2.5.15 H0-00 – Outdoor unit: Voltage/current sensor problem .............................................................................. 25
2.5.16 H6-00 – Outdoor unit: Malfunction of position detection sensor ................................................................ 26
2.5.17 H8-00 – Outdoor unit: Malfunction of compressor input system................................................................. 27
2.5.18 H9-00 – Outdoor unit: Malfunction of outdoor air thermistor ..................................................................... 28
2.5.19 J3-00 – Outdoor unit: Malfunction of discharge pipe thermistor ................................................................. 28
2.5.20 J6-00 – Outdoor unit: Malfunction of heat exchanger thermistor ............................................................... 28
2.5.21 L3-00 – Outdoor unit: Electrical box temperature rise problem................................................................... 29
2.5.22 L4-00 – Outdoor unit: Malfunction of inverter radiating fin temperature rise ............................................ 30
2.5.23 L5-00 – Outdoor unit: Inverter instantaneous overcurrent .......................................................................... 30
2.5.24 P4-00 – Outdoor unit: Malfunction of radiating fin temperature sensor ..................................................... 32
2.5.25 U0-00 – Outdoor unit: Shortage of refrigerant ............................................................................................. 32
2.5.26 U2-00 – Outdoor unit: Defect of power supply voltage ................................................................................ 33
2.5.27 U4-00 – Indoor/outdoor unit communication problem................................................................................ 34
2.5.28 UA-00 – Indoor unit, outdoor unit mismatching problem ............................................................................ 35
2.6 Symptom based troubleshooting ................................................................................................................................... 36
2.6.1 Operation does not start................................................................................................................................ 36
2.6.2 Operation sometimes stops ........................................................................................................................... 36
2.6.3 Operation starts but the unit does not cool/heat ......................................................................................... 37
2.6.4 Operating noise and vibrations...................................................................................................................... 38
2.6.5 Abnormal high pressure ................................................................................................................................. 39
2.6.6 Abnormal low pressure .................................................................................................................................. 40
2.6.7 Indoor fan starts operating but the compressor does not operate.............................................................. 41
2.6.8 Operation starts and the unit stops immediately.......................................................................................... 42
2.6.9 Operation stops, unit cannot start for a while .............................................................................................. 42
2.6.10 Unit discharges white mist ............................................................................................................................. 43
2.6.11 Swing flap does not operate .......................................................................................................................... 43
3 Components 44
3.1 4-way valve...................................................................................................................................................................... 44
3.1.1 Checking procedures...................................................................................................................................... 44
3.1.2 Repair procedures .......................................................................................................................................... 47
3.2 Compressor ..................................................................................................................................................................... 50
3.2.1 Checking procedures...................................................................................................................................... 50
3.2.2 Repair procedures .......................................................................................................................................... 56
3.3 Compressor thermal protector....................................................................................................................................... 61
3.3.1 Checking procedures...................................................................................................................................... 61
3.3.2 Repair procedures .......................................................................................................................................... 62

Table of contents
Service manual
5
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
3.4 Expansion valve............................................................................................................................................................... 65
3.4.1 Checking procedures...................................................................................................................................... 65
3.4.2 Repair procedures .......................................................................................................................................... 69
3.5 Indoor unit fan motor ..................................................................................................................................................... 72
3.5.1 Checking procedures...................................................................................................................................... 72
3.5.2 Repair procedures .......................................................................................................................................... 73
3.6 Indoor unit main PCB...................................................................................................................................................... 74
3.6.1 Checking procedures...................................................................................................................................... 74
3.6.2 Repair procedures .......................................................................................................................................... 77
3.7 Inverter PCB .................................................................................................................................................................... 80
3.7.1 Checking procedures...................................................................................................................................... 80
3.7.2 Repair procedures .......................................................................................................................................... 81
3.8 Main PCB ......................................................................................................................................................................... 81
3.8.1 Checking procedures...................................................................................................................................... 81
3.8.2 Repair procedures .......................................................................................................................................... 89
3.9 Outdoor unit fan motor .................................................................................................................................................. 90
3.9.1 Checking procedures...................................................................................................................................... 90
3.9.2 Repair procedures .......................................................................................................................................... 92
3.10 Plate work ....................................................................................................................................................................... 94
3.10.1 Outdoor unit ................................................................................................................................................... 94
3.10.2 Indoor unit ...................................................................................................................................................... 100
3.11 Reactor ............................................................................................................................................................................ 104
3.11.1 Checking procedures ...................................................................................................................................... 104
3.11.2 Repair procedures .......................................................................................................................................... 105
3.12 Swing flap motor............................................................................................................................................................. 106
3.12.1 Checking procedures ...................................................................................................................................... 106
3.12.2 Repair procedures .......................................................................................................................................... 107
3.13 Thermistors ..................................................................................................................................................................... 108
3.13.1 Refrigerant side thermistors .......................................................................................................................... 108
3.13.2 Other thermistors........................................................................................................................................... 115
4 Third party components 118
4.1 Electrical circuit............................................................................................................................................................... 118
4.1.1 Checking procedures...................................................................................................................................... 118
4.1.2 Repair procedures .......................................................................................................................................... 119
4.2 Refrigerant circuit ........................................................................................................................................................... 120
4.2.1 Checking procedures...................................................................................................................................... 120
4.2.2 Repair procedures .......................................................................................................................................... 124
4.3 External factors ............................................................................................................................................................... 127
4.3.1 Checking procedures...................................................................................................................................... 127
5 Maintenance 129
5.1 To clean the outdoor unit heat exchanger..................................................................................................................... 129
5.2 To clean the indoor unit heat exchanger ....................................................................................................................... 129
5.3 To clean the indoor unit heat exchanger in extreme condition .................................................................................... 130
5.4 To clean the front panel ................................................................................................................................................. 130
5.5 To clean the air filters ..................................................................................................................................................... 130
6 Technical data 132
6.1 Detailed information setting mode ................................................................................................................................ 132
6.1.1 Detailed information setting mode: Indoor unit ........................................................................................... 132
6.1.2 Detailed information setting mode: Outdoor unit ........................................................................................ 132
6.1.3 Detailed information setting mode: Remote controller................................................................................ 132
6.2 Wiring diagram................................................................................................................................................................ 133
6.2.1 Wiring diagram: Indoor unit........................................................................................................................... 133
6.2.2 Wiring diagram: Outdoor unit........................................................................................................................ 137
6.3 Piping diagram ................................................................................................................................................................ 141
6.3.1 Piping diagram: Indoor unit............................................................................................................................ 141
6.3.2 Piping diagram: Outdoor unit......................................................................................................................... 142
6.4 Component overview...................................................................................................................................................... 144
6.4.1 Component overview: Indoor unit................................................................................................................. 144
6.4.2 Component overview: Outdoor unit.............................................................................................................. 145
6.5 Field information report ................................................................................................................................................. 146
6.6 Service tools .................................................................................................................................................................... 149
6.7 Field settings ................................................................................................................................................................... 150
6.7.1 Field settings: Indoor unit .............................................................................................................................. 150
6.7.2 Field settings: Outdoor unit ........................................................................................................................... 151

1 | Safety precautions
Service manual
6
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
1 Safety precautions
The precautions described in this document cover very important topics, follow
them carefully.
All activities described in the service manual must be performed by an authorized
person.
If you are NOT sure how to install, operate or service the unit, contact your dealer.
In accordance with the applicable legislation, it might be necessary to provide a
logbook with the product containing at least:
information on maintenance, repair work, results of tests, stand-by periods, …
Also, at least, following information must be provided at an accessible place at the
product:
▪Instructions for shutting down the system in case of an emergency
▪Name and address of fire department, police and hospital
▪Name, address and day and night telephone numbers for obtaining service
In Europe, EN378 provides the necessary guidance for this logbook.
1.1 Meaning of warnings and symbols
DANGER
Indicates a situation that results in death or serious injury.
DANGER: RISK OF ELECTROCUTION
Indicates a situation that could result in electrocution.
DANGER: RISK OF BURNING/SCALDING
Indicates a situation that could result in burning/scalding because of extreme hot or
cold temperatures.
DANGER: RISK OF EXPLOSION
Indicates a situation that could result in explosion.
WARNING
Indicates a situation that could result in death or serious injury.
WARNING: FLAMMABLE MATERIAL
CAUTION
Indicates a situation that could result in minor or moderate injury.
NOTICE
Indicates a situation that could result in equipment or property damage.

1 | Safety precautions
Service manual
7
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
INFORMATION
Indicates useful tips or additional information.
1.2 Dangers
DANGER: RISK OF BURNING/SCALDING
▪Do NOT touch the refrigerant piping, water piping or internal parts during and
immediately after operation. It could be too hot or too cold. Give it time to return
to normal temperature. If you MUST touch it, wear protective gloves.
▪Do NOT touch any accidental leaking refrigerant.
DANGER: RISK OF ELECTROCUTION
▪Turn OFF all power supply before removing the switch box cover, connecting
electrical wiring or touching electrical parts.
▪Where applicable, stop the equipment's operation first and allow (refrigerant)
pressure to equalize, before turning OFF the power.
▪Disconnect the power supply for more than 10minutes, and measure the voltage
at the terminals of main circuit capacitors or electrical components before
servicing. The voltage MUST be less than 50VDC before you can touch electrical
components. For the location of the terminals, see the wiring diagram. If the
measured voltage is still higher than 50VDC, discharge the capacitors in a safe
manner by using a dedicated capacitor discharge pen to avoid possibility of
sparking.
▪Do NOT touch electrical components with wet hands.
▪Do NOT leave the unit unattended when the service cover is removed.
▪Protect electric componennts from getting wet while the service cover is opened.
1.3 Warnings
WARNING
Improper installation or attachment of equipment or accessories could result in
electrical shock, short-circuit, leaks, fire or other damage to the equipment. ONLY
use accessories, optional equipment and spare parts made or approved by Daikin.
WARNING
Do NOT apply any permanent inductive or capacitance loads to the circuit without
ensuring that this will NOT exceed the permissible voltage and current permitted for
the equipment in use.

1 | Safety precautions
Service manual
8
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
WARNING
If a fault exists that could compromise safety, Do NOT connect electrical supply to
the circuit until it is satisfactorily dealt with. If the fault CANNOT be corrected
immediately but it is necessary to continue operation, an adequate temporary
solution MUST be used. This MUST be reported to the owner of the equipment so all
parties are advised.
Initial safety checks MUST include that:
▪capacitors are discharged: this MUST be done in a safe manner to avoid
possibility of sparking,
▪NO live electrical components and wiring are exposed while charging, recovering
or purging the system.
WARNING
Make sure that the refrigerating piping and components are installed in a position
where they are unlikely to be exposed to any corroding substance.
WARNING
Make sure installation, testing and applied materials comply with applicable
legislation (on top of the instructions described in the Daikin documentation).
WARNING
Make sure the work site environment is clean and safe to work in. Beware of spilled
fluids, like water, oil or other substances.
Protect bystanders from injury and property from possible damage cause by service
works.
WARNING
If any work is to be conducted on the refrigerating equipment or any associated parts
which involves brazing, an appropriate dry powder or CO2 fire extinguisher MUST be
present.
When charging the unit, an appropriate dry powder or CO2 fire extinguisher MUST be
present.
WARNING
No person carrying out work in relation to a refrigerating system which involves
exposing any pipe work shall use any sources of ignition in such a manner that it may
lead to the risk of fire or explosion. All possible ignition sources, including cigarette
smoking, MUST be kept sufficiently far away from the site of installation, repairing,
removing and disposal, during which refrigerant can possibly be released to the
surrounding space. Prior to work taking place, the area around the equipment is to
be surveyed to make sure that there are no flammable hazards or ignition risks. "No
Smoking" signs MUST be displayed.
WARNING
Tear apart and throw away plastic packaging bags so that nobody, especially
children, can play with them. Possible risk: suffocation.
WARNING
During tests, NEVER pressurise the product with a pressure higher than the
maximum allowable pressure (as indicated on the nameplate of the unit).

1 | Safety precautions
Service manual
9
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
WARNING
Make sure the total refrigerant charge is in accordance with the room size in which
the unit is installed: please consult the detailed instructions on charging and allowed
room sizes in the installation manual.
WARNING
▪NEVER mix different refrigerants or allow air to enter the refrigerant system.
▪NEVER charge recovered refrigerant from another unit. Use recovered refrigerant
only on the same unit where it was recovered from, or have it recycled at a
certified facility.
WARNING
When reconnecting a connector to the PCB, make sure to connect it on the correct
location and do NOT apply force, as this may damage the connector or connector
pins of the PCB.
WARNING
ALWAYS recover the refrigerant. Do NOT release them directly into the environment.
Use a vacuum pump to evacuate the installation.
WARNING
Removal of refrigerant MUST be according to the following:
When breaking into the refrigerant circuit to make repairs, be sure to remove the
refrigerant from the system first. The refrigerant charge MUST be recovered into the
correct recovery cylinders.
WARNING
Take sufficient precautions in case of refrigerant leakage. If refrigerant gas leaks,
ventilate the area immediately. Possible risks:
▪Excessive refrigerant concentrations in a closed room can lead to oxygen
deficiency.
▪Toxic gas might be produced if refrigerant gas comes into contact with fire.
WARNING
▪Under no circumstances, potential sources of ignition SHALL be used in the
searching for or detection of refrigerant leaks. A halide torch (or any other
detector using a naked flame) MUST NOT be used.
▪Ensure that the detector is NOT a potential source of ignition and is suitable for
the detection of R32.
▪If a leak is suspected, all naked flames MUST be removed or extinguished.
▪Leak detection fluids are also suitable for use with most refrigerants but the use
of detergents containing chlorine MUST be avoided as the chlorine may react
with the refrigerant and corrode the copper pipe-work.
▪If a leakage of refrigerant is found which requires brazing, all of the refrigerant
MUST be recovered from the system, or isolated (by means of shut‑off valves) in
a part of the system remote from the leak.
▪Only use the electronic leak tester for R32. The old flame leak tester CANNOT be
used on a system with HFC refrigerant because there is no chlorine component in
the refrigerant. In case of R32 (HFC) refrigerant, any flame in contact with
(leaking) refrigerant is extremely dangerous.

1 | Safety precautions
Service manual
10
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
WARNING
▪In order to prevent oxygen deficiency and R32 combustion, keep the room well-
ventilated for a healthy work environment. Do NOT work in a confined space. If a
refrigerant leak is detected in a confined room or an inadequately ventilated
location, do NOT start the work until the area has been ventilated appropriately.
▪If the work area is NOT located in the open air, make sure the work area is
adequately ventilated before breaking into the system or conducting any brazing.
The ventilation MUST continue to operate during the period that the work is
carried out to prevent accumulation of refrigerant in the work area. The
ventilation should safely disperse any released refrigerant and preferably
ventilate to the open air.
WARNING
Ensure that no external live wiring is exposed while charging, recovering or purging
the system. Sparks created when live wiring is short-circuited might ignite the
refrigerant if it is leaked into the room while charging, recovering or purging the
system.
WARNING
Ensure that the unit is properly earthed prior to conducting maintenance or service
or charging the system with refrigerant. Do NOT earth the unit to a utility pipe, surge
absorber, or telephone earth. Incomplete earthing may cause electrical shock.
WARNING
▪ONLY use copper wires.
▪Make sure the field wiring complies with the applicable legislation.
▪All field wiring MUST be performed in accordance with the wiring diagram
supplied with the product.
▪NEVER squeeze bundled cables and make sure they do NOT come in contact with
the piping and sharp edges. Make sure no external pressure is applied to the
terminal connections.
▪Make sure to install earth wiring. Do NOT earth the unit to a utility pipe, surge
absorber, or telephone earth. Incomplete earth may cause electrical shock.
▪Make sure to use a dedicated power circuit. NEVER use a power supply shared by
another appliance.
▪Make sure to install the required fuses or circuit breakers.
▪Make sure to install an earth leakage protector. Failure to do so may cause
electrical shock or fire.
▪When installing the earth leakage protector, make sure it is compatible with the
inverter (resistant to high frequency electric noise) to avoid unnecessary opening
of the earth leakage protector.
WARNING
Make sure the markings on the unit remain visible and legible after inspection or
repair work. Markings and signs that are illegible shall be corrected.
WARNING
▪After finishing the electrical work, confirm that each electrical component and
terminal inside the electrical components box is connected securely.
▪Make sure all covers are closed before starting up the unit.

1 | Safety precautions
Service manual
11
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
WARNING
▪The area MUST be checked with an appropriate refrigerant detector prior to and
during work, to ensure the technician is aware of potentially toxic or flammable
atmospheres.
▪Ensure that the leak detection equipment being used is suitable for use with all
applicable refrigerants, i.e. non-sparking, adequately sealed or intrinsically safe.
▪Prior to and during work, the area MUST be checked with an appropriate
refrigerant detector capable of detecting R32 refrigerant, to ensure a work
environment free of refrigerant.
WARNING
▪Equipment MUST be labelled stating that it has been de-commissioned and
emptied of refrigerant.
▪The label MUST be dated and signed.
▪For appliances containing flammable refrigerants, ensure that there are labels on
the equipment stating the equipment contains flammable refrigerant.
WARNING
Before carrying out refrigerant recovery procedure, it is essential that the technician
is completely familiar with the equipment and all its details. It is recommended good
practice that all refrigerants are recovered safely. Prior to the task being carried out,
an oil and refrigerant sample MUST be taken in case analysis is required prior to re-
use of recovered refrigerant. It is essential that electrical power is available before
the task is commenced.
▪Become familiar with the equipment and its operation.
▪Isolate system electrically.
▪Ensure that mechanical handling equipment is available, if required, for handling
refrigerant cylinders.
▪Ensure that all personal protective equipment is available and is used correctly.
▪Ensure that the recovery process is supervised at all times by a competent
person.
▪Ensure that recovery equipment and cylinders are conform to the appropriate
standards.
▪If a vacuum is NOT possible, make a manifold so that refrigerant can be removed
from various parts of the system.
▪Make sure that cylinder is situated on the scales before recovery takes place.
▪Start the recovery machine and operate in accordance with instructions.
▪Do NOT overfill cylinders (no more than 60% volume liquid charge).
▪Do NOT exceed the maximum working pressure of the cylinder, NOT even
temporarily.
▪When the cylinders have been filled correctly and the process completed, make
sure that the cylinders and the equipment are removed from site promptly and
all isolation valves on the equipment are closed.
▪Recovered refrigerant MUST NOT be charged into another refrigerating system
unless it has been cleaned and checked.
WARNING
All maintenance staff and others working in the local area MUST be instructed on the
nature of work being carried out.

1 | Safety precautions
Service manual
12
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
WARNING
Provide adequate measures to prevent that the unit can be used as a shelter by small
animals. Small animals that make contact with electrical parts can cause
malfunctions, smoke or fire.
WARNING
Prior to start working on systems containing flammable refrigerant, safety checks are
necessary to ensure that the risk of ignition is minimised. Therefore, some
instructions should be followed.
Please refer to the service manual for more information.
WARNING
▪In case refrigerant recovery is required, use the appropriate service ports.
▪If applicable for your unit, use the appropriate recovery mode or field setting to
smoothly recover the refrigerant.
▪ONLY use leak free hoses, couplings and manifolds in good working condition.
▪ONLY use recovery cylinders designated and labelled to recover R32. Note that
thread connection to the cylinder is counter clock.
▪Always use a calibrated scale in good condition prior and during the refrigerant
recovery process to determine the weight of the recovered refrigerant into the
external refrigerant cylinder.
▪Read the operation instructions of the recovery unit prior to connecting the
recovery unit. Verify the recovery unit is suited for R32 refrigerant, check that it is
in good working condition, has been properly maintained and that any associated
electrical components are sealed to prevent ignition in the event of a refrigerant
release. Consult manufacturer if in doubt.
▪Do NOT overfill the refrigerant cylinder, confirm with the supplier of the
refrigerant cylinder about maximum filling ratio if NOT mentioned on the
refrigerant cylinder itself. Generally the maximum filling amount should be
limited to 60% of the maximum volume of the cylinder.
▪Do NOT exceed the maximum working pressure of the refrigerant cylinder, NOT
even temporarily.
▪When the cylinders have been filled correctly, and the refrigerant recovery
process is completed, make sure that the cylinders and the equipment are
removed from site promptly and all stop valves on the equipment are (kept)
closed.
▪The recovered refrigerant MUST be returned to the refrigerant supplier in the
correct recovery cylinder, and the relevant waste transfer note arranged. Do NOT
mix refrigerants in recovery units and especially NOT in cylinders.
▪Recovered refrigerant MUST NOT be charged into another refrigerant system
unless it has been cleaned and checked.
WARNING
If compressor is to be removed, ensure that the compressor has been evacuated to
an acceptable level to make sure that flammable refrigerant does NOT remain within
the lubricant. The evacuation process MUST be carried out prior to returning the
compressor to the supplier. During the refrigerant recovery, confirm that the
crankcase heater of the compressor body is energized to accelerate this process.
When oil is drained from a system, it MUST be carried out safely.

1 | Safety precautions
Service manual
13
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
1.4 Cautions
CAUTION
Wear adequate personal protective equipment (protective gloves, safety glasses,…)
when installing, maintaining or servicing the system.
CAUTION
To avoid injury, do NOT touch the air inlet or aluminium fins of the unit.
CAUTION
▪Do NOT place any objects or equipment on top of the unit.
▪Do NOT sit, climb or stand on the unit.
1.5 Notices
NOTICE
▪Make sure water quality complies with EU directive 2020/2184.
▪Check the system for leaks after each repair/modification of the water side.
▪Check drainage system(s) after repairs.
▪Be careful when tilting units as water may leak.
NOTICE
Make sure refrigerant piping installation complies with applicable legislation. In
Europe, EN378 is the applicable standard.
NOTICE
Make sure the field piping and connections are NOT subjected to stress.

2 | Troubleshooting
Service manual
14
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
2 Troubleshooting
2.1 To display the error code on the user interface
1Hold for about 5seconds.
Result: blinks in the temperature display section.
2Press repeatedly until a continuous beep is heard.
Result: The code is now displayed on the display.
INFORMATION
▪A short beep and 2 consecutive beeps indicate non-corresponding codes.
▪To cancel the code display, hold for 5seconds. The code will also disappear
from the display if the button is NOT pressed within 1minute.
2.2 To reset the error code via remote controller
Prerequisite: Problem is solved.
1Press the ON/OFF button of the remote controller to reset the error.
2.3 To reset the error code via outdoor unit
Prerequisite: Problem is solved.
1Perform a power reset to reset the error code.
2.4 To perform a test run
INFORMATION
If the unit runs into an error during commissioning, see the service manual for the
detailed troubleshooting guidelines.
Prerequisite: Power supply MUST be in the specified range.
Prerequisite: Test run may be performed in cooling or heating mode.
Prerequisite: Test run should be performed in accordance with the operation
manual of the indoor unit to make sure that all functions and parts are working
properly.
1In cooling mode, select the lowest programmable temperature. In heating
mode, select the highest programmable temperature. Test run can be
disabled if necessary.
2When the test run is finished, set the temperature to a normal level. In cooling
mode: 26~28°C, in heating mode: 20~24°C.
3The system stops operating 3minutes after the unit is turned OFF.

2 | Troubleshooting
Service manual
15
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
INFORMATION
▪Even if the unit is turned OFF, it consumes electricity.
▪When the power turns back on after a power break, the previously selected
mode will be resumed.
2.4.1 To perform a test run in winter season
When operating the air conditioner in Cooling mode in winter, set it to test run
operation using the following method.
1Press to switch the system on.
2Press the centre of and simultaneously.
3Press twice.
Result: will appear on the display. Test run operation is selected. Test run
operation will stop automatically after about 30minutes.
4To stop operation, press .
INFORMATION
Some of the functions CANNOT be used in the test run operation mode.
If a power failure occurs during operation, the system automatically restarts
immediately after power is restored.
2.5 Error based troubleshooting
2.5.1 A1-00 – PCB abnormality
Trigger Effect Reset
The system CANNOT set
the internal settings.
Unit will stop operating. Power reset via outdoor
unit.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1Check for improper combination of the indoor unit and the outdoor unit. See
the combination table in the Databook for more information.
2Perform a check of the power supply, connections, wiring,… between the
outdoor unit and the indoor unit. See "4.1Electrical circuit"[4118].
Possible cause: Faulty wiring between the outdoor unit and the indoor unit.
3Check if the power supply is compliant with the regulations. See "4.1Electrical
circuit"[4118].

2 | Troubleshooting
Service manual
16
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
Possible cause:
▪Faulty or disturbance of the power supply (power supply MUST be within
range of nominal operating voltage ±4%),
▪Power drop,
▪Short circuit.
4Perform a check of the indoor unit main PCB. See "3.6 Indoor unit main
PCB"[474].
Possible cause: Faulty indoor unit main PCB.
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
2.5.2 A5-00 – Outdoor unit: High pressure peak cut / freeze protection problem
Trigger Effect Reset
During cooling operation,
indoor heat exchanger
temperature is below 0°C
(freeze‑up protection
control).
Unit will stop operating. Automatic reset when
temperature is within
range.
During heating operation,
indoor heat exchanger
temperature is above
65°C (heating peak‑cut
control).
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1Check for objects near the indoor unit that may block the airflow. See
"4.3External factors"[4127].
Possible cause: Airflow of the indoor unit is blocked.
2Clean the air filter of the indoor unit(s). See "5Maintenance"[4129].
Possible cause: Faulty or dirty air filter.
3Clean the indoor unit heat exchanger. See "5Maintenance"[4129].
Possible cause: Dirty indoor unit heat exchanger.
4Perform a check of the indoor unit heat exchanger thermistor. See
"3.13Thermistors"[4108].
Possible cause: Faulty indoor unit heat exchanger thermistor.
5Perform a check of the indoor unit main PCB. See "3.6 Indoor unit main
PCB"[474].
Possible cause: Faulty indoor unit main PCB.

2 | Troubleshooting
Service manual
17
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
2.5.3 A6-00 – Indoor unit fan motor abnormality
Trigger Effect Reset
The rotation speed of the
fan motor is NOT
detected while the output
voltage to the fan is at its
maximum.
Unit will stop operating. Power reset via the
outdoor unit.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1Perform a check of the indoor unit main PCB. See "3.6 Indoor unit main
PCB"[474].
Possible cause: Faulty indoor unit main PCB.
2Perform a check of the indoor unit fan motor. See "3.5 Indoor unit fan
motor"[472].
Possible cause: Faulty indoor unit fan motor.
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
2.5.4 C4-00 – Heat exchanger temperature sensor problem
Trigger Effect Reset
Refrigerant liquid
thermistor detects an
open or short circuit
during compressor
operation.
Unit will stop operating. Power reset.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1Perform a check of the indoor unit heat exchanger thermistor. See
"3.13Thermistors"[4108].
Possible cause: Faulty indoor unit heat exchanger thermistor.
2Perform a check of the indoor unit main PCB. See "3.6 Indoor unit main
PCB"[474].
Possible cause: Faulty indoor unit main PCB.

2 | Troubleshooting
Service manual
18
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
2.5.5 C9-00 – Room thermistor abnormality
Trigger Effect Reset
Resistance value is out of
range. Temperature
measured <–43.6°C or
>90°C.
Unit will stop operating. Automatic reset when
resistance is within range.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1Perform a check of the indoor unit air (room) thermistor. See
"3.13Thermistors"[4108].
Possible cause: Faulty indoor unit air (room) thermistor.
2Perform a check of the indoor unit main PCB. See "3.6 Indoor unit main
PCB"[474].
Possible cause: Faulty indoor unit main PCB.
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
2.5.6 E1-00 – Outdoor unit: PCB defect
Trigger Effect Reset
Main PCB detects that
EEPROM is abnormal.
Unit will stop operating. Manual reset via user
interface.
Power reset.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1Perform a check of the main PCB. See "3.8Main PCB"[481].
Possible cause: Faulty main PCB.
2Check if the power supply is compliant with the regulations. See "4.1Electrical
circuit"[4118].
Possible cause:
▪Faulty or disturbance of the power supply (power supply MUST be within
range of nominal operating voltage ±4%),
▪Power drop,
▪Short circuit.

2 | Troubleshooting
Service manual
19
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
3Perform a check of the outdoor unit fan motor. See "3.9 Outdoor unit fan
motor"[490].
Possible cause: Faulty outdoor unit fan motor.
4Perform a check of the compressor. See "3.2Compressor"[450].
Possible cause: Faulty compressor or miswiring of the compressor power
supply cable.
Prerequisite: Stop the unit operation via the user interface.
Prerequisite: Turn OFF the respective circuit breaker.
5Wait until the rectifier voltage is below 10VDC.
DANGER: RISK OF ELECTROCUTION
Wait for at least 10 minutes after the circuit breaker has been turned OFF, to be sure
the rectifier voltage is below 10VDC before proceeding.
6Check that the thermal interface grease is applied properly on the (PCB or
refrigerant piping) contact surface of the heat sink. Adjust if needed.
Possible cause: Thermal interface grease NOT applied properly on the heat
sink.
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
2.5.7 E5-00 – Outdoor unit: Overheat of inverter compressor motor
Trigger Effect Reset
Compressor overload is
detected.
Unit will NOT stop
operating.
Automatic reset if the unit
runs without warning for
60seconds.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1Check that all stop valves of the refrigerant circuit are open. See
"4.2Refrigerant circuit"[4120].
Possible cause: Closed stop valve in the refrigerant circuit.
2Perform a check of the discharge pipe thermistor. See
"3.13Thermistors"[4108].
Possible cause: Faulty discharge pipe thermistor or connector fault.
3Perform a check of the outdoor unit fan motor. See "3.9 Outdoor unit fan
motor"[490].
Possible cause: Faulty outdoor unit fan motor.
4Perform a check of the compressor. See "3.2Compressor"[450].
Possible cause: Faulty compressor or miswiring of the compressor power
supply cable.
5Perform a check of the expansion valve. See "3.4Expansion valve"[465].

2 | Troubleshooting
Service manual
20
RXQ25+35AMV1B + ARXQ25+35AMV1B + FTXQ25+35AMV1B +
ATXQ25+35AMV1B
Split Sensira R32 BBOP
ESIE21-16 – 2022.02
Possible cause: Faulty expansion valve.
6Perform a check of the 4‑way valve. See "3.14-way valve"[444].
Possible cause: Faulty 4‑way valve.
7Perform a check of the main PCB. See "3.8Main PCB"[481].
Possible cause: Faulty main PCB.
8Check if the refrigerant circuit is correctly charged. See "4.2 Refrigerant
circuit"[4120].
Possible cause: Refrigerant shortage.
9Check for the presence of non‑condensables and/or humidity in the
refrigerant circuit. See "4.2Refrigerant circuit"[4120].
Possible cause: Non‑condensables and/or humidity in the refrigerant circuit.
10 Check if the refrigerant circuit is clogged. See "4.2Refrigerant circuit"[4120].
Possible cause: Clogged refrigerant circuit.
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
2.5.8 E6-00 – Outdoor unit: Compressor startup defect
Trigger Effect Reset
The motor rotor does
NOT rotate when the
compressor is energized.
Unit will NOT stop
operating.
Automatic reset after a
continuous run for
10minutes.
Unit will stop operating Manual reset via user
interface.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1Perform a check of the discharge pipe thermistor. See
"3.13Thermistors"[4108].
Possible cause: Faulty discharge pipe thermistor or connector fault.
2Check that all stop valves of the refrigerant circuit are open. See
"4.2Refrigerant circuit"[4120].
Possible cause: Closed stop valve in the refrigerant circuit.
3Check if the refrigerant circuit is clogged. See "4.2Refrigerant circuit"[4120].
Possible cause: Clogged refrigerant circuit.
4Check if the refrigerant circuit is correctly charged. See "4.2 Refrigerant
circuit"[4120].
Possible cause: Refrigerant overcharge or shortage.
5Check for the presence of non‑condensables and/or humidity in the
refrigerant circuit. See "4.2Refrigerant circuit"[4120].
Possible cause: Non‑condensables and/or humidity in the refrigerant circuit.