In Australia, air conditioning has become a crucial part of our homes. Not only does a high-quality unit provide comfort for the whole family, but it can also ensure overall health and safety in our country’s harsh climate.
Like any other complicated piece of machinery, you are bound to run into some issues over the lifespan of your air conditioning unit. This includes those with Daikin air conditioners.
Some air conditioning issues may require consultation with a qualified air conditioning technician to fix, while some are more or less a “turn on and off” troubleshooting situation. The lack of distinction between the two is why we have put together this guide.
Access to Daikin air conditioner solutions and error codes can help you cut through the noise. Then, you can decide whether it is a DIY situation or a more pressing issue requiring a professional’s insight.
Having provided air conditioning services to NSW for nearly two decades, Alliance Climate Control’s (ACC) technicians have been there and seen it all. That is why we recognise that sometimes the seemingly costly problem with your air conditioner is a matter of simple diagnostics and easy-to-follow solutions.
So, why pay more for a solution you can apply yourself?
ACC believes in helping out the everyday Australian with their Daikin air conditioning unit. That is why we have provided detailed solutions to the most common problems associated with Daikin products, covering both indoor and outdoor units:
If you are looking for a more general troubleshooting guide, be sure to check out our main air conditioning troubleshooting guide. It contains simple-to-follow video instructions and a collection of other brand-specific guides.
Whether you have an outdoor or indoor unit from Daikin, there is bound to be a moment when your AC is not working as optimally as desired. It can be hard to identify what is wrong with your unit, which is why we have identified some of the most common problems a Daikin product can face:
Dirty air filters are one of the most common causes of air conditioning malfunction. The build-up of debris in the unit can become blockages that prevent air circulation or proper temperature control.
To prevent this issue, the air filters should be changed regularly on a schedule advised by the manufacturer of your system. Failing to do this will result in the air conditioner working slowly, using more energy and eventually freezing and failing to function or failing to start at all.
More frequent changes of the air filters may be required if your home has:
Set yourself a reminder when your air filters need cleaning or changing to stay on top of this issue.
If your system is leaking water, there might be a hole or a crack in the drain pan which controls the overflow of water in the system. A crack or a hole in the drain pan can often be seen by simply using a flashlight, although not always so easily identified.
A blocked air filter may also be the cause of the leakage. By being clogged with dirt, the filter doesn’t allow sufficient airflow. Hence, condensation occurs and the system begins to leak.
The clogged air filters can be diagnosed by visually checking them and also testing the airflow to see how efficiently air is being produced through them.
If you are unable to identify a crack or clogged air filter in your Daikin AC unit, it is best to get an expert technician in to offer aid.
Leakages from the refrigerant tank of an AC unit can be brought about by vibration during the usage of the system. It can also be caused by a knock or a bump to the system and its piping. To evade such occurrences, when installed, your system should be mounted and well-grounded.
A refrigerant leak can be extremely detrimental to health, so if you suspect that the refrigerant is leaking you should call an AC expert for repair or replacement ASAP. Do not try to fix this issue yourself to prevent any harm to you or other occupants’ wellbeing.
A blown fuse is another issue that can cause the air conditioner to break down.
The fuse protects the motor and the compressor. If the fuse blows there might be bigger problems underlying your air conditioning system, which can be traced to its installation or a fluctuating amount of power from the power source.
Alternatively, if the fuse looks to be okay but the power supply is still not available, make sure the circuit breaker is not turned off. Additionally, the power cord plug may not be connected securely to the service outlet.
These simple checks and corrections can help ensure your AC unit is operating optimally without the need to bring in Daikin air conditioning specialists.
There may be times when your Daikin remote controller is not having any effect on your AC unit. In this case, the first thing to do is change the batteries in the remote. If the remote control display is faded, this supports the chance that the controller’s batteries are low in power.
If your AC is still not responding to the remote controller, try resetting said remote. Just hold down the on/off button for a few seconds. Then, power the remote back on and attempt to control the AC unit once again.
In the case that your remote has stopped working, you can also turn your air conditioner on/off by manually pressing the respective button on the unit. If nothing changes, you may have a power supply issue. Check if the circuit breaker is switched on in your electrical box or reach out to an air conditioning technician if the problem cannot be identified.
When there is a flashing green light on your Daikin air conditioner unit, this indicates a fault or operational alert. Common issues indicated by this green light include:
If you cannot identify any of these issues or the flashing green light persists, it is best to call an air conditioning technician for maintenance support.
A smelly air conditioner can be a serious cause of discomfort in your working environment and home. Bacteria build up within your air conditioning system can be responsible for the bad odour. This buildup can only occur when the system has not been regularly cleaned.
When your air conditioner will not start, or if the unit stops unexpectedly between cooling, it more than likely means that it is having a mechanical problem.
The best thing to do in such an instance is to get a professional service technician to look at the issue. The technician will provide a full assessment and if the system is damaged beyond restoration he can provide you with advice on a replacement.
Mechanical breakdowns are often brought about by the lack of regular maintenance of the air conditioning system. The air conditioner should be assessed once or twice a year to check if it is in good condition and to prevent minor issues before they turn into major repairs.
There are a multitude of reasons why your Daikin air conditioner is running but its air flow is not changing in temperature. The usual suspects are:
Most of these problems tend to cause incorrect signals to be sent to the AC unit, prevent efficient heating/cooling, or block air from flowing optimally. However, cooling issues can also be caused by refrigerant leaks or levels.
It can be helpful to check the refrigerant levels of your AC unit if you notice it is no longer cooling effectively. Low levels can cause poor cooling, leaving your home feeling overly warm as cold air fails to be transmitted.
Now that you have read up on some of the most common causes for a Daikin AC breakdown, here are some simple solutions that may help rectify these issues.
A Daikin air conditioner can fail to start due to a blown fuse, wherein there is no completion of the circuit needed to supply power. It can be solved by replacing the fuse.
Otherwise, the power source itself could be the root cause. If the fuse is working well, make sure to check and test your power source for glitches.
Air conditioner leakage originates from the destroyed drainage pan. If you notice leaks, the first place to asses is if there might be cracks or holes in the drain pan.
To remedy this issue, you will need to replace the drain pan, which will often require the expertise of an AC technician. It can also be beneficial to keep the air conditioner clean from dirt since this can add to leakage issues by causing the drain pan to overflow.
If your Daikin air conditioner fails to turn off, the wiring aspect of the system could be the problem. A qualified technician can check your wiring and correct the problem.
If you notice such a problem, it is important to not switch on the AC system until the problem is resolved. This is because wiring issues can expose you to electrical shocks. For your health and safety, it is best to trust such an issue to a trained professional.
Heating or cooling malfunctions in an air conditioner might arise from a thermostat that is not working well. If the thermostat is set to the correct temperature but is not putting out the appropriate airflow, you may need to reset the unit. If the problem persists, it may be an internal issue.
One of the more notable examples of internal AC issues causing temperature mishaps can be a frozen evaporator coil. Evaporation is vital for cooling, and if it, or a condenser coil, is damaged it can prevent cool air from flowing through a unit. Only professionals can amend such an issue.
The other possible cause of heating and cooling issues in an AC system is a clog in the condensate drain line. If you notice a buildup of water in its respective pan, this part should be cleaned to get the cool air flowing once more.
A smelly air conditioner will almost always be attributed to clogged or dirty air filters. This also reduces the efficiency of your air conditioning system, often resulting in more energy consumption and significantly higher energy bills.
To stop this from happening, we need to clean our air conditioning system regularly. During this process, it is best to also use coil cleaners and filter deodorisers to chemically clean your unit.
The prevention of odours is not the only reason to ensure regular AC cleaning. Healthy indoor environments cannot be maintained with an unclean AC unit as it can spread bacteria and other germs. Put your health and safety first by regularly cleaning your air conditioner and its most vital components.
Noise from the air conditioning system results from a clogged air filter. In turn, this causes the system to experience hardship while doing its function as air can only leave the area through a small gap. The air being pushed through this limited space can create a noticeable noise that can become distracting over time.
To avoid this noise pollution, clean the system regularly and also replace your air filter regularly.
| Type of Error Code | Malfunction Contents | Potential causes |
| A1 | Micro-computer in PCB is not working | PCB assembly issue or external noise |
| A3 | Drain level is too high | Clogged drain or faulty drain pump |
| A5 | Overheating or freezing of indoor heat exchanger | Dirty air filter, short circuit, or sensor issue |
| A6 | Fan motor error | Fan motor locked, overloaded, or faulty connection |
| A7 | Swing flap motor error | Swing flap motor fault or faulty connection |
| AH | Dust collector error | Dust collector fault or dirty element |
| AJ | Capacity setting error | Faulty capacity or address setting |
| C3 | Abnormal water level sensor resistance | Disconnected, short circuited, or faulty sensor |
| C4 | Abnormal resistance level of indoor heat thermistor | Disconnected or short circuited thermistor |
| C9 | Abnormal resistance of indoor unit suction air thermistor | Cable disconnection or short circuit |
| CE | Abnormal radiation thermistor resistance | Faulty, disconnected, or short circuited thermistor |
| CJ | Abnormal remote controller thermistor resistance | Built-in remote controller fault |
| E0 | Outdoor unit protection devices activated | Clogged refrigerant piping, insufficient refrigerant, or compressor/fan motor fault |
| E3 | High pressure is too high (HPS activation) | Short circuited or overloaded condenser, dirty heat exchanger |
| E4 | Low pressure is too low (LPS activation) | Clogged piping, insufficient refrigerant, or faulty LPS switch |
| E5 | Overheating of compressor (OL activation) | Clogged piping, low refrigerant, or faulty OL/connection |
| F3 | Outdoor unit discharge temperature is too high | Insufficient refrigerant, clogged piping, or faulty thermistor |
| H9 | Abnormal resistance of the outdoor air temperature thermistor | Faulty thermistor, cable disconnection, or short circuit |
| J5 | Abnormal resistance of the suction pipe temperature thermistor | Faulty thermistor, cable disconnection, or short circuit |
| J6 | Abnormal resistance of the outdoor heat exchanger thermistor | Faulty or short circuited thermistor, or disconnected cable |
| P1 | Open phase power voltage imbalance | Three phase or open phase voltage imbalance |
| U0 | Suction pipe temperature is too high | Clogged piping, lack of refrigerant, or faulty expansion valve |
| U1 | Reverse phase | Reversed three phase power supply |
| U2 | Open phase or power voltage imbalance | Open phase, voltage imbalance, power failure, or low DC voltage of fan motor |
| U4 | Communication error between indoor and outdoor/BS units | Wiring mistake or PCB fault |
| U5 | Communication error between indoor unit and remote controller | Wiring mistake or PCB fault in remote controller |
| UA | Combination or setting error of indoor/BS/outdoor unit | Incorrect quantity or models combination |
This troubleshooting guide for Daikin air conditioning units is fairly comprehensive, covering the most common issues you may encounter. However, if your current issue is not covered here, chances are it is a more serious problem with a technical aspect of your air conditioner.
In these cases, you should get a professional Alliance Climate Control service technician to act on the problems as soon as possible. That way, you can resolve the concerns before they develop into major issues, which would evidently cost a lot more time and money to fix.
In more severe cases, such as an air conditioning system going years without servicing, the unit may need to be replaced entirely.
Ideally, it is better to get an experienced team to work on your air conditioner and service it regularly in order to prevent major breakdowns. At ACC, our HVAC family is equipped with highly qualified experts in air conditioning repair.
Although we always encourage our customers to stick with the most effective solution within their budget, there are times when repairing the AC unit may not be the most cost-effective option. In some cases (especially when the air conditioning system is significantly outdated), the parts required to fix the system may end up costing you a fortune.
Our friendly ACC technicians will always provide tailored recommendations for your specific AC model. These recommendations will always come with transparent pricing that weighs up the pros and cons of repair. Usually in these cases, however, it can be far more beneficial to opt for air conditioner replacement over repair.
We are all about sustainable HVAC practices, so you can also save a pretty penny by trading in your old malfunctioning system as part of our exclusive online promotions for air conditioner replacement.
If you are looking for qualified Daikin air Conditioning replacement or repair, Alliance Climate Control is here to help! With over 15 years of experience in all things Daikin and air conditioning, we provide NSW residents with high-quality cooling and heating solutions tailored to their needs.
If you have noticed a problem with your Daikin AC unit, give us a call and we will drive out to anywhere in NSW for a free quote anytime!
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