Dealing with a malfunctioning air conditioning system can be frustrating, but resetting your Daikin air conditioner can often resolve many common issues. This updated guide for 2024 provides step-by-step instructions on resetting Daikin ducted, split-system, and multi-split system units, decode error codes, and troubleshoot common problems.
The remote controller can receive relevant error codes from the indoor unit.
When 
is held down for about 5 seconds, “00” blinks in the temperature display section.
repeatedly until a long beep is produced.| SYSTEM | CODE | MEANING |
|---|---|---|
| 00 | NORMAL | |
| UA | INDOOR-OUTDOOR UNIT COMBINATION FAULT | |
| U0 | REFRIGERANT SHORTAGE | |
| U2 | DROP VOLTAGE OR MAIN CIRCUIT OVERVOLTAGE | |
| U4 | FAILURE OF TRANSMISSION (BETWEEN INDOOR UNIT AND OUTDOOR UNIT) | |
| INDOOR UNIT | A1 | INDOOR PCB DEFECTIVENESS |
| A5 | FREEZE-UP PROTECTOR | |
| A6 | FAN MOTOR FAULT | |
| C4 | FAULTY HEAT EXCHANGER TEMPERATURE SENSOR | |
| C9 | FAULTY SUCTION AIR TEMPERATURE SENSOR | |
| OUTDOOR UNIT | E1 | CIRCUIT BOARD FAULT |
| E5 | OL STARTED | |
| E6 | FAULTY COMPRESSOR START UP | |
| E7 | DC FAN MOTOR FAULT | |
| E8 | OVERCURRENT INPUT | |
| F3 | HIGH TEMPERATURE DISCHARGE PIPE CONTROL | |
| F6 | HIGH PRESSURE CONTROL (IN COOLING) | |
| H0 | SENSOR FAULT | |
| H6 | OPERATION HALT DUE TO FAULTY POSITION DETECTION SENSOR | |
| H8 | DC CURRENT SENSOR FAULT | |
| H9 | FAULTY SUCTION AIR TEMPERATURE SENSOR | |
| J3 | FAULTY DISCHARGE PIPE TEMPERATURE SENSOR | |
| J6 | FAULTY HEAT EXCHANGER TEMPERATURE SENSOR | |
| L3 | ELECTRICAL PARTS HEAT FAULT | |
| L4 | HIGH TEMPERATURE AT INVERTER CIRCUIT HEATSINK | |
| L5 | OUTPUT OVERCURRENT | |
| P4 | FAULTY INVERTER CIRCUIT HEATSINK TEMPERATURE SENSOR |
While a reset can fix minor issues, more complex problems with your Daikin air conditioner might require expert attention. If your Daikin AC is not turning on after a reset, or you’re encountering repeated error codes, it’s time to call in the professionals.
At PenAir, we specialise in Daikin air conditioning systems. Our team of skilled technicians is equipped to handle everything from tricky troubleshooting to new installations, regular maintenance, and repairs.
For any air conditioning issues in Sydney, contact PenAir for reliable and expert service. Our commitment to excellence and customer satisfaction ensures your needs are met with professionalism and care.
We offer installation and maintenance services for air conditioning in Northern Beaches, Inner West, and Eastern suburbs, including Bondi, Randwick, Vaucluse, and more. Find your suburb in our complete list of Sydney service areas.
The reset function for a Daikin air conditioner is typically activated through the remote control. Instead of a separate reset button, the On/Off button acts as the Daikin Air Conditioner reset button.
To manually reset your Daikin AC unit, press and hold the On/Off button (Daikin AC reset button) on the remote for two seconds, then release it and press it twice more. This sequence acts as a reset for the unit.
To reset a Daikin fault, you must enter the diagnostic mode using the remote control to retrieve the fault code. Then, use the On/Off button to reset the unit. If the fault persists, professional assistance may be required.
If you experience issues like your Daikin AC not turning on, check for any power supply issues first. If the power supply is fine, try resetting the unit using the remote control. Persistent starting issues might indicate a more serious problem needing professional attention.
If you used to have a silent or relatively silent air conditioning system and suddenly it starts to be noisy, it might be time to call in an expert. Most noise is due to clogged or dirty fans and filters. Cleaning all these parts is best left to someone who knows what they are getting into. Aside from débris, the culprit can also wear belts or loose attachments or tightenings. The latter possibility is more serious and will necessitate a proper diagnosis. To avoid potential damage, it is best to check any suspicious noise immediately.
Air conditioner outdoor units require adequate ventilation to provide the best air conditioning. The condensers are located outside and should be in a clear area. Any furniture, plants, or the like should be removed if it is blocking proper ventilation to the outdoor condenser. A sufficient inflow and outflow of air from outside will make the air indoors fresher and colder. It also prevents heat buildup in the air compressor. This ensures a longer life for your air conditioning system. Keeping the compressor at least three feet away from anything blocking airflow is wise.
Your ducted air conditioning system is designed to drain water and collect it into a pan that drains through a line away from your house. However, the pan will sometimes overflow or the line will clog. As a result, drainage issues arise. Drainage issues can also result in a working air conditioner, but one that does not actually produce cold air. Backed-up water may also cause damage to the building, house and surrounding areas. Water damage is no laughing matter and can be very expensive if left unchecked as time goes on. Leaks and water spots may be the most apparent signs of drainage issues. A specialised HVAC technician should investigate this issue and act quickly to prevent the most damage.
Believe it or not, many air conditioning issues are more related to your household habits than the unit itself. Closing all windows and doors is essential for better air conditioning efficiency. Also, applying a sealant to window air conditioning systems will keep warm air from entering and cold air from exiting. Sealing your door spaces underneath with a special cloth roll will also help prevent air from escaping. Using curtains that are known to block sunlight and heat will also boost the efficiency of every air conditioning system. Another alternative to curtains is using blinds on windows for better insulation. If your stove does not have a ventilation hood to suck away the hot air from cooking, it might be time to buy one – this will also make your AC unit work less.
Your system might be noisy depending on where the noise is coming from.
Check your filters are clean. If they are clogged, this restricts the airflow, and the system overworks and gets noisy trying to draw in the required air.
A fan could be out of balance or have a problem with the fan motor. Contact Peninsula Air Conditioning for service.
If you have a ducted system with zones, one of the zone motors may be faulty. Contact Peninsula Air Conditioning for service.
Slide the remote panel down to reveal the other buttons. Find the mode button. This will toggle between various operation modes: Dry (raindrops), Cool (snowflake), Heat (sun), Fan (fan), and Auto (A in a box). Each press of the mode button will switch between these different modes. Select which mode you would like.
Note for Multi-Split systems: One outdoor unit is needed for multiple indoor units. When more than one indoor unit operates, priority is given to the first unit turned on. In this case, set the units to turn on later in the same operation mode as the first unit. Otherwise, they will enter the ‘Standby Mode’, and the operation lamp will flash — THIS DOES NOT INDICATE A MALFUNCTION COOL / DRY and FAN mode may be used simultaneously. However, if AUTO / COOL / HEAT is required, then the mode necessary has to be selected on the first unit to switch on, with the others to follow suit.
There will be a mode button on the wall controller. This will toggle between various operation modes: dry (raindrops), Cool (snowflake), Heat (sun), Fan (fan), and Auto (A in a box). Each press of the mode button will switch between different modes. Select which mode you would like.
This happens when the smells of the room, furniture or cigarettes are absorbed into the unit and discharged with airflow. An internal cleaning of the system is recommended. Contact Peninsula Air Conditioning for service.
Vermin can rip holes in the duct and make it their home, especially if it’s underfloor. Live and dead vermin have been found in ductwork on several occasions. Contact Peninsula Air Conditioning. We can assess and remove the offending animal if possible. We may advise that you need a pest controller to attend as well.
Anything is possible. However, moving a system can be time-consuming and expensive. Sometimes, there is no choice due to building work, etc, but please be aware of what is involved. The system must be pumped down (refrigerant gas reclaimed into the outdoor unit), disconnected, moved to the new location and reconnected. Depending on the new location, more materials may be required or be in a more difficult area to install. So we would do this in 2 visits. The first visit would be to disconnect the system and store it in a safe, dry and dust-free location at your premises. Whilst we are there, we will discuss the new location installation with you and forward this information back to the office, where a quote for reinstallation will be generated. Moving a system after installation may invalidate the manufacturer’s warranty.
As a general rule, you should clean your air filter when the filter light flashes, but this will vary depending on the air quality in your home and other environmental factors. In dusty or polluted environments, you should clean your filters more regularly. As a rule, you should clean your filters once every season in a typical domestic environment and once a month for commercial applications.
These generally have two types of filters: a standard filter and a bio-antibody filter. We can order the system’s model number before your service if you have the system’s model number. Alternatively, we can provide general service, take details, and order the filters. Daikin Split System Air Conditioners feature air-purifying filters that trap most microscopic airborne particles, help decompose odours, and absorb and deactivate bacteria and viruses.
This depends upon your setup, the location of your return air, and the filter type; sizes can also vary. The main ones are…
Cloth filter/media—which can be washed and vacuumed. Over time, the filter media will need replacing, or a whole new filter with a frame will be ordered for you. These are not always standard sizes and generally have to be custom-made.
Filter Boxes—These cardboard filters come in standard sizes and generally need regular replacement. Green filters are the standard pleated filters, while white filters have better filtration with a finer media blend—great for Asthma sufferers.
Purtech filters—These filters fit Purtech return air grilles. They have a plastic surround with nylon mesh and come in 3 different sizes. They will last a long time and can be washed with warm, soapy water.
Click here to see our warranty periods, this includes the manufacturer’s warranty.
Peninsula Air Conditioning offers a Domestic Maintenance Program. For each year you continue with the program, we will extend the installation warranty up to a maximum of 5 years. See here for more details. It does not cover every eventuality but is a worthwhile investment.
You can download a Daikin domestic warranty card here. However, your system’s model and serial number should be enough for you to log a warranty call with the manufacturer directly.
We may be able to give you a rough indication of the cost over the phone. However, a firm price will not be given until we have assessed your property/premises. All recommendations will be emailed.
Every home is different, and the right air conditioner will depend on many factors, such as room orientation, window size and ceiling insulation, to name but a few. It’s an important decision to get right, as an air conditioner that’s too small won’t adequately heat or cool your home, but one that’s too large will be inefficient and expensive.
No, we only install systems we supply.
Read our article on air conditioning running cost to get an idea.
Generally speaking, in summer, thermostats should be set 24°C–26°C. Every 1°C lower can increase running costs by up to 15%. If there is a hot day forecast, pre-cool your house the night before. This is especially effective if your house has a high thermal mass, such as solid brick. This will allow your air conditioner to work optimally during the cool evening, saving the unit’s power and wear and tear. It also allows the unit to keep on top of the heat load as it begins to warm up during the day’s heat. In winter, on the reverse cycle, around 19°C–22°C is usually a good temperature.
On extremely hot days, an air conditioner may not drop the temperature to the set temperature. If it’s 40°C outside, and your air conditioner is set to 18°C, it’s unlikely to reach this set temperature. The air conditioner only has a differential of about 10 °C-12 °C. To help reach your set temperature, check the following:
– All doors and windows to the outside are shut.
– Close all blinds.
– Keep doors to unconditioned areas closed. (laundries, bathrooms, etc.)
– Air is coming out of all outlets.
– The correct thermostat has been selected. (Ducted systems)
Air Conditioning systems contain refrigerant gas, and to work with refrigerant gas, you need to be licensed. The governing body is the Australian Refrigeration Council, which has strict guidelines on handling gases to protect our environment. Companies will have a Refrigerant Trading Authorisation licence, and individuals will have a Refrigerant Handling Licence. Always check that the person coming to install/service your air conditioner has the ARCTick!
This can vary depending on the type of air conditioner, location, and difficulty of access. Generally, a split air conditioner will take anything from a couple of hours to a whole day and a ducted air conditioner a day or two. When we discuss your requirements, we can assess your property and gauge how long it will take.
A suitably qualified technician should install an air conditioner. Installation by anyone else will invalidate the manufacturer’s warranty and be illegal.
Mould and bacteria can build up in an air conditioner; regular maintenance can prevent this. Daikin Split air conditioners also have photocatalytic filters that work as an antibacterial agent for better filtration. The outdoor unit removes carbon monoxide, exhaust gases and foul odours via a thermal catalyst. The indoor unit’s flash streamer technology removes mould, formaldehyde and other allergens from the air. The National Asthma Council rewarded Daikin’s advanced air purifying filtration system, making it the only split system authorised to use the Sensitive Choice symbol.
The Daikin Cora Split system also has a sophisticated titanium apatite photocatalytic air purification filter that traps microscopic airborne dust particles, absorbs bacteria and viruses, and even breaks down odours. A well-maintained air conditioning system can only contribute to a healthier environment.
Because it controls humidity, air conditioning reduces the growth of dust mites and moulds. It maintains humidity levels of 40 – 60%, which is a great feature for people with allergies.
All units are equipped with a filter. A filter’s effectiveness includes catching dust, pollen, bacteria, viruses, odours, and even microbes and smoke.
Additionally, extreme heat harms intellect and physical activity; air conditioning can help rectify this.
It improves comfort levels at work and leisure.
Improves job performance.
It can result in increased physical and intellectual activity.
A lower temperature reduces the presence of insects and parasites.
Lower temperatures mean less sweating, reducing the risk of dehydration.
If the air conditioning installation is sound and well-maintained, it renews and improves air quality.
Looking after your air conditioner will help improve its longevity. Also, consider the environment your air conditioner is situated in, such as close to the sea or a commercial environment that might have a large amount of footfall passing through. In these cases, maintenance may be suggested more regularly. If regularly maintained, an air conditioner can last well over 10 years. However, it may be time to consider a replacement when the air conditioner starts having marginally cost-effective problems.
An annual service is usually sufficient for most domestic environments. However, there may be times when we advise more often.
This can vary and depends upon location and usage type, such as server rooms, medical areas, etc. For some clients, an annual visit is sufficient; however, others may require service as frequently as monthly. If you want a commercial maintenance contract, contact Peninsula Air Conditioning to arrange a technician to assess your best action.
Regular maintenance will help prolong your air conditioner’s life. It will also ensure a healthy environment, keep the system running efficiently, save money on your electricity bills, and prevent unwanted call-outs for problems arising from a lack of maintenance.
Cleaning filters is part of what we do when we service your air conditioner. It is one of the more important maintenance tasks, but there are other things that we can check and do, such as clearing your condensate drain, which would be difficult for you to do yourself. So, even if you clean your filters regularly, we would still suggest regular maintenance.
A general service usually takes about an hour for one system; sometimes, it can take longer if it needs extra attention or has difficult access. Multiple systems in the exact location can reduce the time per system required. For example, for three systems in the same house, we would allow two hours, not three.
Discover what we do in our air conditioning services when we carry out a service on a Ducted, Split and Multi-Split system.
A General Service is a clean system that ensures it works to the best of its ability. This includes checking items that can become troublesome if not cleaned regularly, such as condensate drains. A diagnostic callout occurs when your system has malfunctioned, and a highly qualified technician must test the system to diagnose its fault(s).
It takes about a week on average, but it depends on the time of year and what’s already scheduled. At quieter times, we can usually fit you in sooner; at busy times, there can be a two—to three-week wait. So, if it’s just a service you want, contact us during Spring and Autumn rather than waiting until Summer/Winter.
Quote for the installation of a new system
Again, it depends on the time of year, but it takes about a week on average. Again, Spring and Autumn are good times to start thinking about getting quotes. At busy times, such as October/November, we can get booked up to three weeks in advance. If this happens, we will stop taking on bookings and ask you to contact us again in a week or two if you still want us to quote.
We always try to book appointments for the soonest available date. In quieter times, this could be just a few days; in busier times, it can be a few weeks. We can advise at the time of acceptance.
This comes on after a certain number of running hours. It reminds you to check your filter for cleaning or replacement. If you haven’t had an air conditioner service within the last 12 months, it’s a good time to contact Peninsula Air Conditioning and book one. If you have, you can clear the filter sign by pressing and holding the clear button for at least 3 seconds.
It is OK to turn the power off, especially if you are away for long periods. Most units have a low-wattage crankcase heater that keeps the compressor warm. If the compressor is cold at start-up, damage may occur. If you turn off your air conditioner for long periods, ensure it’s turned on at least 12 hours before use. It is also okay to turn the power off to reset the system.
Check to see if there is a power failure. Wait until power is restored. If a power failure occurs during operation, the system automatically restarts immediately after the power supply recovers. Check if a fuse has blown or the circuit breaker has tripped.
Change the fuse or reset the circuit breaker. Switch off and leave for 20 minutes, then switch back on again. If the system fails again or there is no power, call Peninsula Air Conditioning for repair.
Note the fault code and contact Peninsula Air Conditioning for repair.
Check if obstacles block the air inlet or outlet of the outdoor or indoor unit. If so, remove them and make the area well-ventilated.
Check if the air filter(s) is/are clogged. Clean the air filter(s) (This is done with a soft clean cloth – if stains are difficult to remove use water. The filters should be cleaned at the start of summer and the start of winter.)
Check the following:
See if obstacles block the air outlet of the indoor or outdoor unit. If so, remove the obstacle and make the area well ventilated.
If the air filter is clogged. Clean the filters.
What temperature is the system set to?
If the fan speed control is set to a low speed.
If the doors or windows are open, shut them to prevent external air from entering.
See if direct sunlight enters the room. (When cooling) Use curtains or blinds.
When there are too many occupants in the room, the cooling effect is decreased, as there is too much heat.
Check if the room’s heat source is excessive. The cooling effect decreases if the room’s heat gain is too significant.
Turn OFF the main power switch, leave it for a few minutes and switch it on. If the problem still occurs, please contact Peninsula Air Conditioning for repair – DO NOT keep resetting the system as this could cause further malfunctions.
Switch OFF at the isolator switch or mains switchboard and contact Peninsula Air Conditioning. Failure to do so under such circumstances may result in a power failure, electric shock, or a fire.
This can happen when the system reverts to HEATING operation after DEFROST operation. Moisture generated by the defrost function becomes steam and is released.
This is because the room temperature has reached the set temperature. The indoor unit will switch to fan operation.
Refrigerant gas is used in air conditioners to produce heat and cooling. If there is a refrigerant gas leak, the air may not be as cool or warm as it should be. Refrigerant gas leaks can occur, sometimes due to poor installation and others because a system has been knocked or bashed accidentally, and the seals become broken. You may not be aware that this happens until the system is not working and most of the refrigerant gas leaks out, which could occur over months.
If the “Operation” lamp is on, the system operates normally. It may not restart immediately because one of its safety devices has been activated to prevent system overload. The system will turn on again after about three (3) minutes.
In cooling mode, the air conditioner will not start blowing air until it has cooled the fan coil so that any air produced is cooled. This is to avoid blowing warm air before cooling has taken effect.
Wait one minute until the microcomputer is prepared for operation.
When we come to diagnose a fault in your air conditioner, we do our utmost to fix the problem whilst we are there. However, there are specific reasons why this may not be possible…
Sometimes, the system needs much time to repair; in these circumstances, we must arrange to return to complete this. We will have other jobs booked for that day, and we cannot anticipate how long a repair will take without a technician first assessing it. If this is the case, the technician will report his findings to the office, and our repair recommendations will be emailed to you. Once this is accepted, we will schedule the repair as soon as we are available.
Air conditioning systems are made up of many parts, both electrical and mechanical, and each model has different parts that are generally not interchangeable. We can’t have every part of every system with us. If this is the case, the technician will report his findings to the office, and our repair recommendations will be emailed to you. Once this is accepted, we will order the parts, and as soon as they arrive, we will schedule you for our earliest available repair date.
The health and safety of our technicians is paramount. If the access becomes difficult and/or unsafe, we must return for further work with two technicians.
Not! Everything after the callout allotted time is charged at an hourly rate. So, if the technician returns to repair, this does not incur another callout charge.
This is the million-dollar question. Certain things must be considered when deciding whether to repair or replace.
The age of the system?
How much is it going to cost to replace the system?
How much is the repair? Other faults may occur after the initially diagnosed fault is repaired.
The warranty period on parts/repair is compared to a replacement.
Wait time for repair—Some older system parts can be unavailable or even have to be sourced from overseas, and this can take 6-8 weeks at a minimum.
We recommend paying a technician to assess the faulty system before deciding. We will credit your Diagnostic Callout fee if you choose a replacement rather than a repair.
Ducted systems can be designed so that only parts of the house (zones) are air-conditioned at any time. Check that the zone switch is turned on. If you are still having problems, Peninsula Air Conditioning offers service.
Please turn off the mains switch or isolator, leave it off for at least 20 minutes, and then switch it back on. If the problem still occurs, please contact Peninsula Air Conditioning for service.
Indoor dirt, dust, and debris can build up inside the air conditioner; mix this with humidity, and the condensate drain can get blocked. Regular servicing should keep this clear. Condensate drains can run into the house’s downpipes; if this gets clogged with leaves and debris, it can back up your condensate drain. If your water comes from the indoor unit, switch it off immediately and contact Peninsula Air Conditioning.
Indoor Units—If your indoor unit is on the roof, a safety tray will be installed to catch any condensate that overflows. This will then drain to a small pipe coming out of the side of your house, usually just above the eve. If you see this leaking, switch off your system immediately and contact Peninsula Air Conditioning.
If the remote does not display, check the batteries. To remove the batteries, slide the remote panel down to reveal the other buttons. When it stops, give it an extra tug to slide the panel off completely. The battery compartment should now be exposed. If replacing the batteries does not fix the issue, then note the model number (ARC) on the back of the remote and contact Peninsula Air Conditioning for a replacement.
Alternatively, some remotes can be purchased from our website – visit our store. If the remote has a display but is not controlling the air conditioner, there may be an issue with one of the boards inside the air conditioner. Try resting the system from the primary power source, switch the power to the air conditioner off and leave it off for 20 to 30 minutes. When you switch the system back on, leave it for 15 minutes to gather itself. If you continue to have issues, you will need a technician to assess them.
If your wall controller isn’t working, check that the main power to your air conditioner is on. Also, check the isolator switch by the outdoor system and the trip switch in your fuse box. If these are all on, contact us.
The wall controller will display a fault code when the system malfunctions. Note this code and reset your system by switching off the mains power and leaving it for 20 – 30 minutes. This reset may be all you need to fix the issue; however, if the system malfunctions again or doesn’t work after the reset, contact Peninsula Air Conditioning.
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