When the scorching Queensland heat returns in summer, many of us will be cranking our Daikin air conditioner to keep us in blissful comfort. Unfortunately, the system has to work hard to fight the oppressive heat, and as it grinds away for hours on end, its refrigerant depletes, its parts wear down faster, and eventually it’ll give up with a sad splutter, and you’ll be drenched with sweat faster than you can say “Crown Power.”
If you’re in a sticky situation like this, and you’d rather attempt your own fix before calling in the professionals, this Daikin air conditioner troubleshooting guide will help you on your way. We tackle the most common questions that we receive from clients whose Daikin air conditioner has suddenly thrown down its tools and refused to work—everything from “why is my Daikin aircon not working?” to “what does this flashing green light mean?”
Daikin troubleshooting doesn’t have to be arduous. In this Daikin AC troubleshooting guide, we offer quick and easy tips on how to fix almost every issue you can think of, including whether it’s safe for you to do so.
To troubleshoot, or not to troubleshoot?
You may be surprised to learn that if you’re having air con problems, you don’t necessarily need to call a technician out. Often, there’s an easy solution to get your air con up and working again, which is why we’ve created this Daikin inverter troubleshooting guide.
If troubleshooting your Daikin air conditioner isn’t going as planned, and none of the suggestions below work, we recommend giving us a call. We’re authorised Daikin specialists, and are able to offer fast, affordable help.
Table of contents
- Daikin air con won’t turn on
- Daikin aircon is not cooling
- Daikin air conditioner has a flashing green light
- Daikin air conditioner has a flashing orange light
- Daikin indoor air con is leaking
- The mould proof/cleaning lamp is flashing green on my Daikin air conditioner
- Daikin AC remote control is not working
- Daikin AC remote control digital display doesn’t show
- The remote control works intermittently, or the display is faded
- I’ve lost the remote control for my Daikin air con
- Daikin air con is making a noise
- Daikin air con smells
- Daikin heat pump won’t turn on
- Daikin AC keeps switching off automatically
- Daikin’s heating stopped unexpectedly, and I hear water flowing
- Daikin air conditioner won’t turn off
- Daikin air con won’t reach the set humidity level
- My outdoor air con unit is releasing water or steam
- Daikin air con is tripping the breaker or fuse
- The flap (louvre) doesn’t close when my Daikin air con is turned off
- Daikin AC stops after 24 hours
- Daikin zone controller is not working
- Daikin air conditioner fault codes
Daikin aircon troubleshooting—the full list
Daikin air con won’t turn on
Wondering why your Daikin inverter isn’t turning on? Here are a few simple checks you can do to figure out the problem, and reset your Daikin air conditioner.
If the on/off button is off
- Check that the fuse isn’t blown and that there isn’t a power failure
- Make sure that the power cord is properly connected to the outlet
- Double check the batteries in the remote
- Check to see if the timer has been set
If the operation lamp is flashing (green flashing light)
- Unplug from power or turn off the circuit breaker
- Wait for at least a minute, then turn the power back on
- If the operation lamp continues to flash, you should contact your retailer, or call an air conditioning expert for professional advice
Daikin aircon is not cooling
Before starting these tests, close all windows and doors to the room you’re cooling, to seal the air inside.
If your air conditioner is not producing cold air:
1. Double check the temperature on your remote
Your remote will display a number in degrees Celsius. Here’s how to set temperature on a Daikin air conditioner:
- Find your air con remote
- Press the up/down buttons on the remote to set the temperature. The best temperature depends on the season and your location.
- In 15 minutes, test that the room reaches the temperature you set using a thermometer.
2. Check that the air filters are clean
Our experts recommend cleaning your air con filters once every two weeks in summer, when it’s used heavily. Otherwise, it’s okay to wash your air-purifying filter once every six months.
Unsure how to clean your Daikin’s air filters? Follow the simple steps in our guide to maintaining your air conditioner.
3. Check that the air con is clear of obstructions
Check that the areas surrounding the air con aren’t blocked by furniture or decor items.
4. Check your doors and windows
Check that the doors and windows to the area are closed, as this will prevent the unit from cooling the area effectively.
5. Check that the sensor is working
If your Daikin aircon is not cooling your room effectively, it may be a Daikin sensor problem. Sometimes, the sensor doesn’t detect people who are far away from the indoor unit. You can troubleshoot this by moving closer to the air con and checking that the air quantity and direction are properly controlled, and that the ventilation fan is moving.
Daikin air conditioner has a flashing green light
If your Daikin air conditioner has a flashing green light, don’t panic. While there are a few different issues that can be indicated by a blinking green light, most of them are pretty easy fixes.
Here are some steps to follow:
- First, slide off the cover of your remote
- Locate the cancel button
- Hold the cancel button down for five to ten seconds
- Release when the temperature disappears from the screen and is replaced by two flashing zeros
- As the zeros begin to flash, continually press the cancel button in time with the blinking
- As you press the button, new two-digit figures will pop up. This is a list of all the possible faults that your air con is experiencing
- If your air con beeps once on a number, it is not the right number for the fault
- If your air con beeps twice, one of the two numbers are correct
- If your air con emits a long continuous beep, both of the numbers are correct. This gives you the correct code to identify the issue
- Search the Daikin air conditioning error codes page for your code. You can match the letter to the number to find out what is wrong, and contact your Daikin air con specialist.
I have a Daikin air conditioning error code—what does it mean?
You can access the full list of Daikin air conditioner fault codes from this page.
Daikin air conditioner has a flashing orange light
If the timer lamp on your AC unit is flashing orange, the Streamer unit needs to be cleaned. To clean the unit, you can follow the instructions on page 36 (under Streamer unit) of this Daikin guide.
Daikin indoor air con is leaking
If water is leaking from your indoor air con, unplug it and contact a professional. It is common for air conditioning units to produce some condensation, but a considerable leak could be a major safety issue, so do not touch the air con unit or attempt to fix it yourself.
The mould proof/cleaning lamp is flashing green on my Daikin air conditioner
This means that the dust box needs to be cleaned. To clean the dust box, you can follow the instructions on page 37 (under Dust box) of this Daikin guide.
Daikin AC remote control is not working
If your Daikin aircon remote isn’t working, first try to reset your Daikin remote or controller.
Here’s how to reset a Daikin air conditioner remote:
- Locate the ‘ON/OFF’ button on your Daikin air con’s remote.
- Press and hold the button for 2 seconds.
- Press the ON/OFF switch once to stop operation.
- Press it a second time to start it again.
If this button on your remote or air conditioning unit is not working, unfortunately, you will need to contact the retailer who sold you the unit, or professional air conditioning technicians such as Crown Power.
Daikin AC remote control digital display doesn’t show
Sounds like a case of flat batteries. Replace the batteries, and if the issue doesn’t improve, contact your distributor.
The remote control works intermittently, or the display is faded
If your remote control seems to be working intermittently, or if the digital display is looking faded, replace the batteries for the controller.
I’ve lost the remote control for my Daikin air con
If you’ve lost the remote control, you can turn the air conditioner unit on and off by pressing the ON/OFF button on the main unit. When this button is used, the AC will use its automatic settings.
Daikin air con is making a noise
If your Daikin air con is making a noise, the first thing to identify is the type of sound. Here are some possibilities:
- Abnormal sound—unplug the power and contact your retailer.
- Clicking sound—the refrigerant control valve or electric component may be operating.
- Buzzing sound—the louvre (the flap that controls the airflow direction) is moving
- Rattling or creaking sound—this is the adjustment of louvres as the unit is starting up
- Bubbling sound—this may be outdoor air entering the drain hose. Generally, this is normal and tends to happen in a well-sealed house, or if you’re living in an apartment.
- Soft rumbling sound—check the ventilation mode. If it’s operating in “fan” it will sometimes make this noise.
- Hissing sound—This is the discharge of humidified or ventilated air. This can occur when it’s humid outside, or during other temperature extremes.
- Abnormal sound when you’re cleaning the filter—unplug the power and contact a professional for advice.
Daikin air con smells
If your air conditioning unit is producing unpleasant smells, the odour may be a sign of bigger problems.
If you smell something burning, switch off power immediately and contact a professional.
If the smell is unpleasant, it’s probably discharge from the unit’s purifying operation. It isn’t hazardous, and should dissipate quickly.
Please don’t apply cleaning spray or odour spray to your air conditioning unit at any stage. It’s not necessary and may cause damage that will void your warranty.
Daikin heat pump won’t turn on
During summer
If your Daikin air conditioner is not producing heat in summer, you may have:
- A clogged filter
- A refrigerant leak
- Dirty coils that block heat transfer
If the filter is clogged and filthy, you can clean this easily by following the instructions in our Daikin Air Conditioner Maintenance guide. If you’ve found a refrigerant leak, or believe that the coils are dirty, turn off your air con immediately to prevent further damage and call a reputable professional for assistance.
During winter
When it comes to Daikin heat pump troubleshooting in winter, here are some possible reasons:
- Your unit is failing to defrost due to faulty relays, controls or sensors
- There is an issue with the reverse valve that switches your unit from heat to cooling
- Your outdoor fan is damaged, or the motor is failing or dead
- Your heat pump is slowly leaking refrigerant
Unfortunately, you’ll need to contact a professional to fix these problems.
Daikin AC keeps switching off automatically
If your air con suddenly stops, or turns on and off repeatedly, this is usually nothing to worry about. When the unit stops unexpectedly, it’s usually protecting itself from voltage fluctuations, and should start working again within a few minutes.
When the temperature in your room reaches the set level the unit switches to “breeze mode” to maintain the temperature. When the temperature fluctuates, the unit will increase the volume of air flow. A stable room temperature is the goal of a good unit, so if this is happening, our Daikin air conditioning troubleshooting guide recommends leaving this well alone.
Daikin’s heating stopped unexpectedly, and I hear water flowing
If your heating stops unexpectedly and you hear the sound of water flowing, your outdoor unit is running its defrost operation. This should resolve itself in about 10 minutes.
Daikin air conditioner won’t turn off
If you’ve turned off the dehumidifier, dry cooling, and cooling settings, and your air con is still working, check your mould proof setting. If it’s on, this is what is preventing your air con from turning off.
Daikin air con won’t reach the set humidity level
If the humidity goes below the set level or doesn’t reach it, there’s a simple fix. If your unit is on “humidifying heating” mode, lower the setting for the temperature. If it’s in “humidifying” mode, increase the humidity setting and select “continuous” operation.
My outdoor air con unit is releasing water or steam
This may be caused by frost on the unit. The pipes on the outdoor unit will get cold during cooling, which produces condensation and causes water to drip. This is usually nothing to worry about unless it causes other problems.
Daikin air con is tripping the breaker or fuse
If your Daikin AC is tripping the breaker or fuse, turn it off immediately and contact the retailer.
The flap (louvre) doesn’t close when my Daikin air con is turned off
If the flap has been touched during operation, it may not close properly. This can easily be fixed by turning the unit on, giving it time to start, and then turning it off again.
Daikin AC stops after 24 hours
If your auto filter cleaning setting is on, your Daikin AC will stop after 24 hours of continuous operation, complete the filter cleaning process, and resume normal operation. This is nothing to worry about.
Daikin zone controller is not working
If you have a ducted air conditioner and your Daikin zone controller is not working, we recommend contacting an air conditioning specialist immediately.
Daikin air conditioner fault codes
Here’s the full list of Daikin air conditioner fault codes, lifted directly from this PDF from Daikin.
If there’s a fault with the Daikin system, this will sometimes show on the remote control or wall-mounted controller. Or you may have to complete a sequence on the remote controller to get the code to appear, which Daikin explains in this document.
It’s highly unlikely that you will be able to fix the fault yourself, but it can give you an idea of what might have gone wrong with the air conditioner. You can also pass the fault code onto the air conditioning technician when you call them so that they come fully prepared.
Fault codes – A to C
Fault code | Fault explanation | Possible causes | Origin of fault |
A0 | External protection device activated | External protection device connected to the terminal strip T1-T2 of indoor unit is activated | Indoor unit |
A1 | Malfunction of indoor unit PCB | Defective indoor unit OCB. | Indoor unit |
A3 | Drain Level Control System Abnormality | Drain clogging, upward slope, etc. Defective drain pump Defective float switch or short circuit connector | Indoor unit |
A4 | Malfunction of freezing protection | Shortage of water volume Low water temperature setting Defective water temperature thermistor | Indoor unit |
A5 | High pressure control in heating, freeze-up protection control in cooling | Clogged air filter of indoor unit and short circuit Defect of indoor unit heat exchanger thermistor | Indoor Unit |
A6 | Malfunction of fan motor | Broken wires in, short circuit of, or disconnection of connectors from the fan motor harness Defective fan motor Defective indoor unit PCB | Indoor unit |
A7 | Malfunction of swing flap motor | Defective swing flap motor Defective indoor unit PCB Defective connection cable Defective airflow direction adjusting flap-cam | Indoor unit |
A8 | Malfunction of power supply or AC input overcurrent | Defective power supply voltage Defective connection on signal line Defective wiring | Indoor unit |
A9 | Malfunction of electronic expansion valve | Defective electronic expansion valve coil Defective indoor unit PCB Defective relay cables | Indoor unit |
AA | Heater overheat | 26WH is activated | Indoor unit |
AF | Malfunction of a humidifier system | Humidifier unit (optional accessory) leaking Defective drain piping (upward slope, etc.) Defective indoor unit PCB | Indoor Unit |
AH | Malfunction of dust collector of air cleaner | Defect of dust collecting element Stained insulator part Defect of high voltage power supply unit Defect of indoor unit PCB | Indoor Unit |
AJ | Malfunction of capacity setting (Indoor unit PCB) | The capacity setting adaptor was not installed when replacing PCB. Defective indoor unit PCB | Indoor unit |
C1 | Failure of transmission (between indoor unit PCB and sub PCB) | Defective connection of the connector between indoor unit PCB | Indoor unit |
C4 | Malfunction of liquid pipe thermistor for heat exchanger | Defective thermistor for liquid pipe Defective indoor unit PCB Defective connector contac | Indoor unit |
C5 | Malfunction of gas pipe thermistor for heat exchanger | Defective thermistor for gas pipe Defective indoor unit PCB Defective connector contact | Indoor unit |
C6 | Malfunction of fan motor sensor or fan control driver | Defective fan PCB Defective connection of capacity setting adaptor Field setting error | Indoor unit |
C7 | Front panel driving motor fault | Defective front panel driving motor Defective limit switch | Indoor unit |
C9 | Malfunction of suction air thermistor | Defective thermistor for suction air Defective indoor unit PCB Defective connector contact | Indoor unit |
CA | Malfunction of discharge air thermistor | Defective thermistor for discharge air Defective indoor unit PCB Defective connector contact | Indoor unit |
CC | Malfunction of humidity sensor system | Defective humidity sensor Defective connector contact | Indoor unit |
CJ | Room temperature thermistor in remote controller abnormality | Defective room temperature thermistor in remote controller Defective remote controller PCB External factor (Noise etc.) | Indoor unit |
Fault codes – E to H
Fault code | Fault explanation | Possible causes | Origin of fault |
E0 | Protection devices activated (unified) | Protection device connected to outdoor unit PCB actuated Defective protection device connector contact | Outdoor unit |
E1 | Protection devices activated (unified) | Defective outdoor unit PCB Defective connection of inside/ outside relay wires | Outdoor unit |
E3 | Actuation of high pressure switch (HPS) | Dirty outdoor unit heat exchanger Defective high pressure switch Clogged refrigerant piping Defective connector contact | Outdoor unit |
E3 | System No.1 Actuation of high pressure switch (HPS) | Dirty outdoor unit heat exchanger Shortage of water volume Clogged refrigerant piping Defective connector contact Defective HPS | Outdoor unit |
E4 | Actuation of low pressure switch (LPS) | Abnormal drop in low pressure Defective low pressure sensor Defective outdoor unit PCB Defective connector contact | Outdoor unit |
E5 | Inverter compressor motor or overheat | Inverter compressor lock High differential pressure Defective inverter PCB UVW connection error Defective connector contact | Outdoor unit |
E6 | STD compressor motor overcurrent/lock | Defective compressor Defective control PCB The stop valve is not opened | Outdoor unit |
E6 | System No.1 Compressor overcurrent | Defective electronic expansion valve Shortage of refrigerant amount Defective compressor | Outdoor unit |
E7 | Malfunction of outdoor unit fan motor system | Fan motor failure Neglect to connect or defective connection of harness/ connector between the fan motor and the PCB Fan does not rotate due to foreign matters caught in it | Outdoor unit |
E8 | Overcurrent of inverter compressor | Defective compressor Defective inverter main circuit capacitor Defect of outdoor unit PCB Defect of power transistor | Outdoor unit |
E9 | Malfunction of electronic expansion valve coil | Disconnection of connectors from electronic expansion valves | Outdoor unit |
EA | Malfunction of four way valve or cool/heat switch | Defective four way valve Shortage of gas Defective outdoor unit PCB Defective thermistor | Outdoor unit |
EC | Malfunction of entering water temperature | Cooling water temperature abnormality Defective outdoor unit PCB Defective thermistor | Outdoor unit |
F3 | Malfunction of discharge pipe temperature | Defective discharge pipe thermistor Abnormal discharge pipe temperature Defective outdoor unit control PCB Defective connector contact | Outdoor unit |
F6 | Abnormal high pressure or refrigerant overcharged | Refrigerant overcharged Disconnection of heat exchanger deicer thermistor Disconnection of outdoor air thermistor Disconnection of liquid pipe temperature thermistor Defective outdoor unit PCB | Outdoor unit |
H0 | Malfunction of sensor system of compressor | Harness is disconnected, or defective connection Defective PCB | Outdoor unit |
H1 | Malfunction of room temperature sensor or humidifier unit damper | Defective limit switch Defective damper | Outdoor unit |
H3 | Malfunction of high pressure switch (HPS) | Defective high pressure switch Broken wire Defective outdoor unit PCB | Outdoor unit |
H4 | Malfunction of low pressure switch (LPS) | Defective low pressure switch Broken wire Defective outdoor unit PCB Defective connector contact | Outdoor unit |
H4 | Malfunction of low pressure switch (LPS) | Defective low pressure switch Broken wire Defective outdoor unit PCB Defective connector contact | Outdoor unit |
H5 | Malfunction of compressor motor overload thermistor | Defect of compressor motor overload thermistor Defective connector contact | Outdoor unit |
H6 | Malfunction of position detection sensor | Faulty contact of compress or cable Defective Defective outdoor unit PCB | Outdoor unit |
H7 | Malfunction of outdoor unit fan motor signal | Abnormal signal from fan motor (Circuit failure) Disconnection/Short circuit in fan motor leads or disconnection of connector Defective inverter PCB | Outdoor unit |
H8 | Malfunction of compressor input (CT) system | Defective power transistor Defective reactor Faulty wiring of inverter system Defective outdoor unit PCB | Outdoor unit |
H9 | Malfunction of outdoor air thermistor | Defective connection of thermistor Defective outdoor unit PCB Defective outdoor air thermistor | Outdoor unit |
HC | Malfunction of (hot) water temperature thermistor | Defective connection of thermistor Defective outdoor unit PCB Defective water temperature thermistor | Outdoor unit |
HF | Alarm in thermal storage unit or storage controller | Thermal storage group defective wiring Defective setting Excess of thermal storage tank numbers | Outdoor unit |
HJ | Malfunction of thermal storage tank water level | Low water level Defective switch setting Water level detecting sensor failure Defective connector contact | Outdoor unit |
Fault codes – J to M
Fault code | Fault explanation | Possible causes | Origin of fault |
J1 | Malfunction of pressure sensor | Defective pressure sensor connector contact Defective pressure sensor Defective outdoor unit PCB | Outdoor unit |
J2 | Malfunction of current sensor of compressor | Defective current sensor Defective compressor Defective outdoor unit PCB | Outdoor unit |
J3 | Malfunction of discharge pipe thermistor | Defective connection of thermistor Defective discharge pipe thermistor Defective outdoor unit PCB | Outdoor unit |
J4 | Malfunction of low pressure equivalent saturated temperature sensor system | Defective connection of thermistor Defective thermistor Defective outdoor unit PCB | Outdoor unit |
J5 | Malfunction of suction pipe thermistor | Defective connection of thermistor Defective suction pipe thermistor Defective outdoor unit PCB | Outdoor unit |
J6 | Malfunction of heat exchanger thermistor | Defective connection of thermistor Defective heat exchanger thermistor Defective outdoor unit PCB | Outdoor unit |
J7 | Malfunction of thermistor (Refrigerant circuit) | Defective connection of thermistor Defective liquid pipe thermistor Defective outdoor unit PCB | Outdoor unit |
J8 | Malfunction of thermistor (Refrigerant circuit) | Defective connection of thermistor Defective liquid pipe thermistor Defective outdoor unit PCB | Outdoor unit |
J9 | Malfunction of thermistor (Refrigerant circuit) | Defective connection of thermistor Defective gas pipe thermistor Defective outdoor unit PCB | Outdoor unit |
JA | Malfunction of high pressure sensor | Defective connector contact Connection of low pressure sensor in mistake for high pressure sensor Defective high pressure sensor Defective outdoor unit PCB | Outdoor unit |
JC | Malfunction of low pressure sensor | Defective connector contact Connection of high pressure sensor in mistake for low pressure sensor Defective low pressure sensor Defective outdoor unit PCB | Outdoor unit |
JE | Malfunction of oil pressure sensor or sub-tank thermistor | Defective connector contact Defective sub-tank thermistor Defective outdoor unit PCB | Outdoor unit |
JF | Malfunction of oil level sensor or heating heat exchanger thermistor | Defective connector contact Defective heat exchanger thermistor Defective outdoor unit PCB | Outdoor unit |
L0 | Malfunction of inverter system | Shortage of power supply capacity Defective power transistor Defective outdoor unit PCB | Outdoor unit |
L1 | Malfunction of inverter PCB | Defective compressor wiring Defective outdoor unit fan motor Blown fuse Defective inverter PCB | Outdoor unit |
L3 | El.compo. box temperature rise | Fin temperature rise due to short circuit Defective outdoor unit fan motor Defective power transistor Defective outdoor unit PCB | Outdoor unit |
L4 | Malfunction of inverter radiation fin temperature rise | Fin temperature rise due to short circuit Defective fin thermistor | Outdoor unit |
L5 | Inverter instantaneous overcurrent (DC output) | Defective compressor coil (such as wiring disconnection or insulation failure) Compressor startup failure (mechanical lock) Defective inverter PCB | Outdoor unit |
L6 | Inverter instantaneous overcurrent (AC output) | Overcharge of refrigerant amount Shortage of power supply capacity Defective compressor Defective inverter unit | Outdoor unit |
L8 | Malfunction of overcurrent inverter compressor | Compressor overloaded Wiring disconnection in compressor coil Disconnection of compressor wiring Defective inverter PCB | Outdoor unit |
L9 | Malfunction of inverter compressor startup error (Stall prevention) | The stop valve is not opened Defective compressor Error in wire connections to compressor Large differential pressure before compressor startup Defective inverter PCB | Outdoor unit |
LA | Malfunction of power transistor | Defective power transistor Defective compressor Defective inverter PCB | Outdoor unit |
LC | Malfunction of transmission between control and inverter PCB | Defective connection between the inverter PCB and the control PCB External factors (e.g. noise) Defective inverter compressor Defective control PCB (transmission block) | Outdoor unit |
M1 | Malfunction of central remote controller PCB | Defective central remote controller PCB | Outdoor unit |
M8 | Malfunction of transmission between optional controllers for centralised control | Other centralised control power disconnection Centralised control reset switch ON Defective transmission wiring Central remote controller address change | Outdoor unit |
MA | Improper combination of optional controllers for centralised control | Improper combination of optional controllers for centralised control More than one master controller is connected Faulty setting of centralised control Defect of centralised control | Outdoor unit |
MC | Address duplication, improper setting | Address duplication of central remote controller | Outdoor unit |
Fault codes – P to U
Fault code | Fault explanation | Possible causes | Origin of fault |
P0 | Shortage of refrigerant amount (thermal storage unit) | Shortage of refrigerant Clogged refrigerant piping | Outdoor unit |
P1 | Power voltage imbalance or inverter PCB | Open phase Interphase voltage imbalance Defective capacitor in the main circuit Defective wiring in the main circuit Defective inverter PCB | Outdoor unit |
P2 | Automatic refrigerant charge operation stop | The stop valve is not opened Closed valve of refrigerant tank | Outdoor unit |
P3 | Malfunction of thermistor in switch box | Defective connection of thermistor Defective reactor thermistor Defective inverter PCB | Outdoor unit |
P4 | Malfunction of radiation fin temperature sensor | Defective radiation fi n temperature thermistor Defective inverter PCB Defective INV. compressor Defective fan motor | Outdoor unit |
P8 | Heat exchanger freezing protection during automatic refrigerant charging | (Close the refrigerant cylinder. Start again from step 1.) | Outdoor unit |
P9 | Malfunction of fan motor (humidifier unit) | Defective fan motor Defective outdoor unit PCB Broken relay harness Defective connector contact | Outdoor unit |
PA | Refrigerant cylinder during automatic refrigerant charging | Refrigerant cylinder of master unit is empty | Outdoor unit |
PA | Broken wire of heater (humidifier unit) | Defective heater unit Defective thermistor Defective outdoor unit PCB | Outdoor unit |
PC | Refrigerant cylinder during automatic refrigerant charging | Refrigerant cylinder of slave unit 2 is empty | Outdoor unit |
PH | Automatic refrigerant charge operation nearly completed | Defective heater unit Defective connector contact Defective thermistor Defective outdoor unit PCB | Outdoor unit |
PJ | Malfunction of capacity setting (Outdoor unit PCB) | Capacity setting adaptor is not installed Improper capacity setting adaptor Defective outdoor unit PCB | Outdoor unit |
PJ | Improper combination between inverter and fan driver | Mis-matching of type of PCB Improper (or no) field setting after replacing outdoor unit main PCB | Outdoor unit |
U0 | Shortage of refrigerant | Refrigerant shortage and refrigerant clogging (wrong piping) Defective thermistor Defective low pressure sensor Defective outdoor unit main PCB | System |
U1 | Reverse phase, open phase | Power supply reverse phase T phase open phase Defective outdoor unit PCB (A1P) | System |
U2 | Malfunction of power supply or instantaneous power failure | Abnormal power supply voltage Instantaneous power failure Defective main circuit wiring | System |
U3 | Check operation not executed or transmission error | Check operation is not executed. | System |
U4 | Malfunction of transmission between indoor and outdoor unit | Short circuit in indoor-outdoor or outdoor-outdoor transmission wiring (F1 / F2), or wrong wiring Outdoor unit power supply is OFF System address does not match Defective indoor unit PCB Defective outdoor unit PCB | System |
U5 | Malfunction of transmission between indoor unit and remote controller | Transmission error between indoor unit and remote controller Connection of 2 main remote controllers (when using 2 remote controllers) Defective indoor unit PCB Defective remote controller PCB Transmission error caused by noise | System |
U6 | Malfunction of transmission between indoor units | Faulty wiring External factor (Noise etc.) Defective indoor unit PCB | System |
U7 | Malfunction of transmission between outdoor units or outdoor storage unit | Connection error of transmission wirings between outdoor unit and external control adaptor for outdoor unit Connection error of transmission wirings between outdoor units Defective outdoor unit PCB | System |
U8 | Malfunction of transmission between remote controllers | Transmission error between main and sub remote controller Connection between sub remote controllers Defective remote controller PCB | System |
U9 | Malfunction of transmission (other system) | Transmission error between other indoor and outdoor units Defective electronic expansion valve of other indoor unit Defective indoor unit PCB of other indoor unit | System |
Fault codes – U to 7C
Fault code | Fault explanation | Possible causes | Origin of fault |
UA | Defect of indoor/outdoor power supply | Wrong model connections Improper power supply Wrong PCB connected Defective PCB | System |
UA | Improper combination of indoor and outdoor units | Excess of connected indoor units Defective outdoor unit PCB Mismatch of the refrigerant type of indoor and outdoor unit Setting of outdoor unit PCB was not carried out after replacing to spare PCB | System |
UA | Remote temperature setting wire disconnection | Remote temperature setting wire disconnection Defective connector contact | System |
UC | Malfunction of setting of centralised control equipment address | Address duplication of centralised control equipment Defective indoor unit PCB | System |
UE | Malfunction of transmission between indoor unit and centralised control equipment | Transmission error between optional controllers for centralised control equipment and indoor unit Connector for setting main controller is disconnected.(or disconnection of connector for independent / combined use changeover switch.) Defective PCB for central remote controller Defective indoor unit PCB | System |
UF | System is not set yet | Improper connection of transmission wiring between indoor-outdoor units and outdoor-outdoor units Failure to execute check operation Defective indoor unit PCB Stop valve is not opened | System |
UH | Malfunction of system | Improper connection of transmission wiring between indoor-outdoor units and outdoor-outdoor units Defective indoor unit PCB Defective outdoor unit PCB | System |
UJ | Malfunction of transmission (accessory device) | Defect of accessory devices Faulty wiring | System |
60 | External protection device activated (Heat reclaim ventilator) | Actuation of external protection device Defective output signal wiring Defective control PCB | Other |
64 | Malfunction of indoor air thermistor (Heat reclaim ventilator) | Defective connector contact Defective indoor air thermistor Defective control PCB | |
65 | Malfunction of outdoor air thermistor (Heat reclaim ventilator) | Defective connector contact Defective outdoor air thermistor Defective control PCB | |
6A | Malfunction of damper system (Heat reclaim ventilator) | Defective connector contact Defective limit switch Defective damper motor | |
70 | System No. 2 Compressor overheat | Shortage of refrigerant amount Defective connector contact Leakage of four way valve | |
71 | System No. 2 Compressor overcurrent | Shortage of refrigerant amount Short circuit Defective | |
72 | System No. 2 Compressor overcurrent | Defective fan motor connector contact Defective fan motor Defective PCB | |
73 | System No. 2 Actuation of high pressure switch (HPS) | Dirty heat exchanger Shortage of water volume Clogged refrigerant piping Defective connector contact Defective HPS | |
74 | System No. 2 Actuation of low pressure switch (LPS) | Clogged refrigerant piping Defective connector contact Shortage of gas Defective LPS | |
75 | System No. 2 Malfunction of low pressure sensor | Defective connector contact Defective low pressure sensor Defective PCB | |
76 | System No. 2 Malfunction of high pressure sensor | Defective connector contact Defective high pressure sensor Defective PCB | |
77 | System No. 1 Malfunction of fan inter lock | Defective relay contact Broken wire | |
78 | System No. 2 Malfunction of fan inter lock | Defective relay contact Broken wire | |
7A | System No. 2 Malfunction of compressor current sensor | Defective current sensor Defective compressor Defective outdoor unit PCB | |
7C | System No. 2 Malfunction of pump inter lock | Cooling water pump interlock actuated |
Fault codes – 80 to 99
Fault code | Fault explanation | Possible causes | Origin of fault |
80 | Malfunction of entering water temperature thermistor | Defective connector contact Defective entering water temperature thermistor | Other |
81 | Malfunction of leaving water temperature thermistor or drain pipe heater | Defective connector contact Defective leaving water temperature thermistor | Other |
82 | System No. 1 Malfunction of refrigerant thermistor | Defective connector contact Defective refrigerant thermistor | Other |
83 | System No. 2 Malfunction of refrigerant thermistor | Defective connector contact Defective refrigerant thermistor | Other |
84 | System No. 1 Malfunction of heat exchanger thermistor | Defective connector contact Defective heat exchanger thermistor | Other |
85 | System No. 2 Malfunction of heat exchanger thermistor | Defective connector contact Defective heat exchanger thermistor | Other |
86 | System No. 1 Malfunction of discharge pipe thermistor | Defective connecting connector Defective discharge pipe thermistor | Other |
88 | System No. 2 Malfunction of discharge pipe thermistor | Shortage of gas Defective discharge pipe thermistor Defective connector contact Clogged refrigerant piping | Other |
89 | Malfunction of brazed-plate heat exchanger freezing | Dirty heat exchanger Shortage of refrigerant amount Defective thermistor | Other |
8A | System No. 2 Malfunction of leaving water temperature thermistor | Defective connector contact Defective leaving water temperature thermistor | Other |
8E | System No. 1 Malfunction of suction pipe thermistor 1 for heating | Defective connector contact Defective suction pipe thermistor | Other |
8F | System No. 1 Malfunction of suction pipe thermistor 2 for heating | Defective connector contact Defective suction pipe thermistor | Other |
8H | Abnormal hot water high temperature | Three way valve malfunction Defective thermistor Defect of water temperature setting | Other |
90 | Abnormal chilled water quantity or abnormal AXP | Shortage of water volume Disconnection of AXP | Other |
91 | System No. 2 Malfunction of electronic expansion valve | Defective connector contact Defective electronic expansion valve coil | Other |
92 | System No. 2 Malfunction of suction pipe thermistor | Defective connector contact Defective suction pipe thermistor | Other |
94 | Malfunction of transmission (between heat reclaim ventilator and fan unit) | Malfunction of transmission (between heat reclaim ventilator and fan unit) | Other |
95 | System No. 1 Malfunction of inverter system | Defective fan inverter unit | Other |
96 | System No. 2 Malfunction of inverter system | Defective fan inverter unit | Other |
97 | Malfunction of thermal storage unit | Defective thermal storage unit | Other |
98 | Malfunction of thermal storage brine pump | Actuation of thermal storage brine pump overcurrent (OC) | Other |
99 | Malfunction of thermal storage brine tank | Low water level of thermal storage brine tank | Other |
Need a little professional help?
Crown Power are authorised Daikin air conditioning specialists. If you need help with Daikin split system troubleshooting or Daikin ducted air conditioning troubleshooting, we’re happy to answer your questions, or to fix your AC for you.
Contact Crown Power today on 0427 175 654 (Brisbane & Sunshine Coast), or 0421 376 620 (Gold Coast).
