Why You Might Need to Reset Your Daikin Air Conditioner
Imagine it's a 38°C Saturday afternoon on Sydney's North Shore and your Daikin split system has stopped responding after last night's storm knocked out the power. The indoor unit is flashing an error code, the remote isn't doing anything useful, and the house is heating up fast. A Daikin air conditioner reset is usually the quickest fix in this situation, and in most cases you can do it yourself in under two minutes.
Daikin units need a reset for a handful of common reasons: a power outage or surge that leaves the system in a fault state, a communication error between the indoor and outdoor unit, a frozen coil that has triggered a protection mode, or a filter indicator light that needs clearing after routine maintenance.
This article covers three reset methods in order of simplicity: a soft reset using the remote control, a hard reset via the circuit breaker at your switchboard, and a filter indicator reset to clear the maintenance reminder.
Key takeaways
- A Daikin air conditioner reset clears temporary faults and restores communication between units in under two minutes.
- Start with a soft reset using the remote, then try a hard reset via the circuit breaker if needed.
- If the same error code returns after resetting, the unit has a hardware fault requiring professional inspection.
Three Ways to Do a Daikin Air Conditioner Reset
Most Daikin faults clear with one of three reset procedures. Start with the softest option and work down the list only if the problem persists. Each method takes a different approach to clearing the system's memory, so choosing the right one depends on what triggered the fault in the first place.
Soft Reset Using the Remote Control
A remote soft reset clears minor communication glitches between the indoor unit's control board and the remote receiver. It takes about 30 seconds and should always be your first step before trying anything else. This procedure works across Daikin's most popular residential models including the Daikin Cora (e.g. FTXM25Y), the Daikin Alira X (e.g. FTXM35Y) and the Daikin Lite series.
- Point the remote directly at the indoor unit's signal receiver, usually located on the front panel below the display.
- Press the On/Off button to turn the unit off. Wait for the unit to fully shut down and for any indicator lights to stop flashing.
- Wait 30 seconds. This gives the control board time to clear its active fault state.
- Press the On/Off button again to restart the unit. Check whether the error code has cleared and whether the unit resumes normal operation.
If the unit starts up normally and holds its set temperature without re-displaying the fault code, you're done. If the error returns within a few minutes, move on to the circuit breaker reset below.
Hard Reset via the Circuit Breaker
A circuit breaker reset cuts power completely to both the indoor and outdoor units, allowing capacitors to fully discharge and the system's firmware to restart from scratch. This is the recommended method after a power outage, a voltage surge, or any fault that the remote reset couldn't clear.
- Turn the unit off using the remote control and wait for it to fully shut down.
- Go to your home's main switchboard. In most Sydney homes this is in the garage, laundry or a hallway cupboard.
- Locate the dedicated AC circuit breaker. It is usually labelled 'Air Con', 'AC' or 'Split System'. Note that older homes in suburbs like Balmain or Leichhardt may have original switchboards where breakers are unlabelled or grouped under a general 'Appliances' circuit. If you're unsure which breaker controls the AC, call a licensed electrician rather than guessing.
- Flip the breaker to the OFF position.
- Wait a full 60 seconds. Thirty seconds is not enough. The outdoor unit's capacitors need the full minute to discharge safely.
- Flip the breaker back to ON.
- Return to the indoor unit and restart it using the remote. Check that the fault code is gone and the system runs through a full cooling or heating cycle.
If the same fault code reappears after a circuit breaker reset, the issue is likely a hardware fault rather than a software glitch. At that point, the unit needs a professional inspection rather than another reset attempt.
Clearing the Filter Reset Indicator
The filter indicator light is not a fault code. It is a maintenance reminder that appears after a set number of operating hours, typically around 250 hours, to prompt you to clean the filters. Clearing it is a separate process from the system resets above and only affects the indicator light, not the unit's operating state.
- Locate the Filter button on your remote control. On most Daikin remotes it is labelled 'Filter' in small text or shown as a grid icon. On entry-level models like the Daikin Lite (e.g. FTXF25D), the button layout can differ slightly from the Cora and Alira X remotes, so check your model's manual if you can't find it.
- Hold the Filter button down for five seconds until the filter indicator light on the indoor unit turns off.
One important point: clearing the indicator does not clean the filter. The reminder exists for a reason, and running a clogged filter reduces airflow, strains the compressor and can cause the unit to ice up. Make sure you have actually cleaned the filters before you reset the light. For a full walkthrough on how to do this properly, see our guide to cleaning your air conditioner.
Common Daikin Error Codes and What They Mean
Daikin units display alphanumeric error codes on the indoor unit's display or via flashing LED patterns when a fault is detected. Some codes clear permanently after a reset because they were triggered by a temporary condition like a power surge or a momentary airflow restriction. Others will reappear within minutes because they point to a hardware fault that no amount of resetting will fix.
The table below covers the five error codes most commonly reported on Daikin residential split systems in Australia. The third column tells you honestly whether a reset is likely to help.
| Error Code | Meaning | Can a Reset Fix It? |
|---|---|---|
| U4 | Communication error between the indoor and outdoor unit | Sometimes. A reset clears the fault if it was caused by a power interruption. If the code returns, the wiring or control board needs inspection. |
| E3 | High pressure fault in the refrigerant circuit | Possibly. If a dirty filter or blocked return air grille caused the pressure spike, cleaning the filter and resetting may resolve it. If the code returns, call a technician. |
| E7 | Outdoor fan motor fault | Unlikely. This code almost always indicates a failed motor or capacitor. A reset will not fix a mechanical fault. Call a technician. |
| L5 | Inverter overcurrent detected | Sometimes. A single reset after a power surge may clear it. If the code reappears, the inverter board or compressor needs professional diagnosis. |
| F3 | Discharge pipe temperature too high | No. This code indicates a refrigerant or compressor issue. Do not continue running the unit. Call a technician. |
As a general rule, if the same error code reappears within an hour of resetting, the unit has a fault that needs professional diagnosis rather than another reset attempt. Repeated resets on an active hardware fault can cause further damage to the inverter board or compressor. Book a same-day inspection through our air conditioning repairs service before the problem escalates.
When a Reset Won't Fix the Problem
A Daikin air conditioner reset clears temporary faults and restores communication between the indoor and outdoor units, but it cannot repair physical components. Refrigerant leaks, failed run capacitors, faulty PCBs, blocked condensate drain lines and compressor failures all require a licensed technician with the right tools and parts. No reset procedure addresses any of these.
Stop resetting and call for a professional inspection if you notice any of the following warning signs:
- The unit restarts and runs but only blows warm air in cooling mode. This points to a refrigerant or compressor issue rather than a software glitch. If this is your situation, our air conditioning not cooling article walks through the most likely causes in detail.
- Water is dripping from the indoor unit onto the wall or floor, which usually means the condensate drain line is blocked or the drain tray is cracked.
- The outdoor unit is making a grinding, rattling or high-pitched squealing noise during operation.
- The unit trips the circuit breaker again within minutes of being reset, which is a sign of an electrical fault that needs urgent attention.
- The same error code returns repeatedly across multiple reset attempts, as covered in the section above.
If your Daikin was professionally installed, it is worth checking whether the fault falls under warranty before paying for repairs out of pocket. Most Daikin residential split systems, including the Cora and Alira X ranges, carry a five-year parts and labour warranty when installed by a licensed contractor. AirFlow Australia is a licensed Daikin installer and can verify your warranty status, diagnose the fault and carry out repairs same-day across Sydney's North Shore and Inner West. To book a professional check, visit our air conditioning service page.
Still Having Trouble? AirFlow Australia Can Help
Most Daikin faults clear with one of three simple reset methods: a 30-second soft reset using the remote control, a full hard reset via the circuit breaker at your switchboard, or a quick filter indicator reset to clear the maintenance reminder. For the vast majority of minor faults on models like the Daikin Cora (FTXM25Y), Alira X (FTXM35Y) and Daikin Lite (FTXF25D), the whole process takes under two minutes.
If the fault code keeps coming back after you've worked through all three methods, the unit has a hardware problem that needs a licensed technician. AirFlow Australia are Sydney's trusted Daikin specialists, fully licensed and Arctick registered, with same-day repair availability across the North Shore and Inner West. Every installation we carry out is backed by a five-year installation warranty.
Call us on 0423 535 905 or book online and we'll have a technician out to you the same day.
Frequently Asked Questions
How to do a hard reset on AC?
A hard reset means cutting power at the circuit breaker, not just switching the unit off via the remote. Turn the unit off using the remote first, then locate the dedicated AC breaker at your switchboard and switch it off. Wait a full 60 seconds before restoring power. This is the most thorough DIY reset method and is recommended after power surges or persistent error codes.
What is the common problem of a Daikin air conditioner?
The most common Daikin air conditioner problems are error codes from communication faults between the indoor and outdoor units (often a U4 code), reduced cooling from dirty filters or low refrigerant, water leaking from the indoor unit due to a blocked drain line, and the unit failing to restart after a power outage. Dirty filters and blocked drains are straightforward DIY fixes, but refrigerant leaks and electrical faults must be handled by a licensed technician.
How do you reset a Daikin after a power outage?
To reset a Daikin after a power outage, wait at least 3 minutes after power is restored before attempting to restart the unit. Daikin inverter systems have a built-in compressor protection delay, so the unit may not respond immediately. If it still does not restart, switch the dedicated AC breaker off for 60 seconds and then back on. If an error code appears and persists after the restart, note the code and contact a technician.
How do I reset my split system?
Resetting a split system follows the same process across most brands: for a soft reset, turn the unit off via the remote, wait 30 seconds and turn it back on. For a hard reset, switch the circuit breaker off for 60 seconds and then restore power. Daikin, Fujitsu and Mitsubishi Electric all follow this general approach, though button labels on remotes differ. If you are unsure what the symbols on your remote mean, our guide to Daikin remote control symbols explains each one clearly.