Daikin Air Conditioner Troubleshooting Guide (8 Problems Solved!)

Australian giant air conditioner brand Daikin promises an array of air conditioning units you can count on annually. But even so, these ACs malfunction or fail at some point, thus requiring a Daikin air conditioner troubleshooting guide.

With a troubleshooting guide, you can troubleshoot a Daikin air conditioner that won’t turn on, respond to its remote control, blow cold or hot air, or turn off. Moreover, you can troubleshoot an option that stops unexpectedly or whose light blinks to indicate a fault.

Those are the key issues I’ll help you troubleshoot. We’ll also look at some common error codes, especially those accompanied by blinking lights, that you can troubleshoot DIY.

The idea is to fix the AC yourself and bypass an expert technician where necessary. Once you do so, you’ll save time and money. So, let’s get into it!  

Daikin air conditioner troubleshooting guide

In a hurry? See below a simple troubleshooting guide for your Daikin air conditioner

Quick Daikin Air Conditioner Troubleshooting Guide

Problem Likely CauseRecommended Fix
1.Daikin AC Won’t Turn On (Lamp Off)Lack of power (power outage, AC not turned on, loose power cord, tripped breaker or blown-up fuse), non-responsive remote, incorrectly set timer, or burnt PCBEnsure your AC has power. Ensure it’s turned on and firmly plugged in. Reset a tripped breaker, and replace a blown-up fuse. Ensure the remote is working and set the timer correctly. But if it still doesn’t turn on, replace the PCB
2.Daikin AC Won’t Respond To The RemoteLow battery (for the remote), incorrect loading, long obstructed range, or damaged sensor or buttonsReplace the batteries and load them correctly. Operate the remote near the AC and away from apparent barriers/walls. Replace the remote if the LED sensor or buttons are damaged
3.Daikin Air Conditioner Not Blowing Cold Air  A high-temperature setting, dirty air filter, surrounding obstruction, open windows and doors, small AC, refrigerant leak, frozen unit, clogged drain or faulty sensor or fanLower the temperature by at least 24 degrees, clean dirty filters, and clear any surrounding obstruction. Shut some doors and windows or upgrade the AC if it’s small. Call an expert to handle a refrigerant leak, frozen unit, clogged drain or faulty sensor, or fan
4.Daikin Air Conditioner Not Blowing Hot AirA low-temperature setting, dirty filter, closed windows and doors, or a faulty fan Raise the Ac temperature, clean the dirty filter, open some windows and doors and replace a faulty fan 
5.Daikin AC Won’t Turn OffMold-Proof setting or faulty wiringDisable the Mold-Proof setting but call an expert to fix faulty wiring
6.Daikin AC Stops Unexpectedly Voltage fluctuation Reset the AC
7.Blinking Lights Green blinking light (dirty dust box)
Orange blinking light (dirty streamer)
Clean the AC and then reset it

7 Common Daikin Air Conditioner Problems

Below are the seven common issues that call for a Daikin air conditioner troubleshooting guide.

1. Daikin Air Conditioner Not Turning On (Lamp Off)

If the Daikin air conditioner doesn’t turn on, which you can tell by an off lamp, the reason could be any of these:

  • Lack of power – There could be a power outage, the AC might not be on, or the power plug could be loose. Furthermore, the AC might not receive power due to a tripped breaker or blown-up fuse. 
  • Non-responsive remote – The remote control’s batteries could be low, and that’s why the AC is not responding, or the remote could be faulty.
  • Incorrectly set timer – If the AC’s timer is incorrectly set, the AC won’t turn on. So, you’ve to examine the timer to ensure it is correctly set. 
  • Burnt PCB – The last option when your air conditioner won’t turn on is a faulty Printed Circuit Board (PCB). The PCB connects to the AC’s electronic components, and so once it burns, which is less likely, the AC won’t turn on. 


Before anything, note that the Daikin AC may take up to 3 minutes after pressing the power switch before running if you’ve just turned it down. But once that’s not the case, ensure you’ve power (there’s no outage) and that the on/off switch is on.

Then check the power cord to ensure it is properly plugged in. 

If the breaker is tripped, reset it, and if the fuse is blown (if it lacks continuity), replace it. You can test the fuse’s continuity with a multimeter.

As for the remote control, you can replace the batteries, especially if you have been using them for over a year, and try operating the remote near the AC.

Then check the timer to ensure it’s set correctly. If the Daikin AC still won’t turn on, replace the PCB. 

2. Your Daikin Air Conditioner Not Responding to Remote Control

I remember mentioning that a non-responsive remote control could be why your Daikin air conditioner won’t turn on. So, you should check it to ensure it’s working.

If it’s not, the reason could be:

  • Low battery power – The Daikin remote control batteries have a 1-year lifespan. Once a year is over, their power drops, making the remote non-responsive. 
  • Incorrect loading – If you wrongly place the batteries into the AC remote control, they won’t work. So, check the battery’s polarity.
  • Long or obstructed range – If you are operating your Daikin AC remote at a distance, perhaps over 20ft, the remote won’t work. Likewise, the remote won’t work if there are barriers or walls.
  • Damaged sensor or buttons – If the remote LED/sensor or its buttons are damaged, the remote won’t work. So, you have to check that.


Replace the remote’s batteries and place them correctly. Ensure there are no barriers when operating the remote and move closer. If the LED or buttons look damaged, replace the remote. 

Daikin air conditioner problems

3. Daikin Air Conditioner Not Cooling

Several issues could prevent your Daikin air conditioner from blowing cold air, some of which are avoidable. The issues in question include:

  • High-temperature setting – If the room temperature is lower than the Daikin thermostat setting, the AC won’t cool. You need the AC temperature to be at least 24 degrees lower than the room temperature. 
  • Dirty air filter – If the air filters are dirty, they’ll obstruct airflow, and the AC will fail to blow cold air. That’s why Daikin recommends cleaning them once in two weeks after heavy AC use (in the summer) and every six months in the other seasons.
  • Surrounding obstructions – Things like heavy furniture and decor could obstruct airflow, thus affecting the AC’s cooling. 
  • Open windows and doors – If all the windows and doors are open, the AC won’t be able to cool your space correctly. You may need to shut some.
  • Small AC – If the air conditioner is too small for your space, it won’t cool; even if it does, you’ll likely not feel the effect.
  • Frozen unit – If the coils are frozen, the air conditioner won’t be able to blow any air and will therefore fail to cool.
  • Refrigerant leak – Issues like vibrations and knocks could lead to a refrigerant leak. Sadly, once the refrigerant level drops, it cannot absorb the extra heat. So, your Daikin air con won’t cool. 
  • Clogged drain – If the condensate drain line is clogged, especially by mold, the AC won’t cool. It won’t blow cold air until you unclog the line. 
  • Faulty sensor or fan – If the Daikin sensor malfunctions, the unit won’t be able to detect temperature changes and will, therefore, not cool. Likewise, a broken fan won’t blow cold air.


Start by ensuring the thermostat setting is at least 24 degrees lower than the room temperature. If it’s not, adjust it accordingly. Then inspect the air filter for dirt clogging and clean them. 

And if there are obstructions around the air conditioner, such as heavy furniture and decor, remove them. 

If all your windows or doors are open, close them and if the AC is too small for your space, upgrade it. However, call an expert in case of a clogged drain, frozen unit, faulty sensor, or fan.

4. Daikin Air Conditioner Not Heating

The Daikin air conditioner may fail to heat up and blow hot air during the winter due to any of these reasons:

  • Low-temperature setting – If the thermostat setting is pretty low, the Ac won’t heat but will cool. So, check that to ensure the thermostat reading is higher than your room temperature.
  • Dirty air filter –Dirty filters will block warm air the same way they block cold air. 
  • Closed windows and doors – If you shut all the windows and doors are closed, the room will feel too hot, preventing the AC from kicking in.
  • Faulty fan – A broken fan cannot effectively blow hot air, and the AC will fail to heat. 


Ensure the AC thermostat setting is higher than the room temperature if that’s not the case. Inspect the air filters for dirt and clean them, especially if it has been over six months.

If all the windows or doors are shut, open some, and if the fan is broken, replace it. 

5. Daikin Air Conditioner Won’t Turn Off

The Daikin air conditioner may sometimes fail to turn off, suggesting a major issue. The problem could be the Mold-Proof setting which is ON.

The setting prevents the AC from turning off. But still, it could be due to a wiring fault. 


Turn off the Mold-Proof setting if it’s on. But if it’s not, call an expert to inspect and fix the wiring. 

Daikin air conditioner fault codes

6. Daikin Air Conditioner Stops Unexpectedly

If your air conditioner stops unexpectedly, but the operation lamp isn’t off, the reason is likely to be a voltage fluctuation. If so, nothing is alarming, as the unit will likely self-restart in 3 minutes. 


Since the AC is likely to restart in 3 minutes, you don’t have to do anything. But if it doesn’t, then you should reset it.  Here’s how to reset Daikin air conditioner:

  • Locate the on/off switch on your remote and press it for 2 seconds
  • Release the switch and then press it once (this time around without holding it down)
  • Press it once for the last time to restart the AC

7. Daikin Air Conditioner Not Working Light Flashing

The timer lamp often blinks to indicate that the unit is dirty and needs cleaning. It’s essential, however, to note the color of the blinking light as follows:

  • Green blinking light shows a dirty dust box
  • An orange blinking light indicates a dirty streamer unit


Clean the AC when you notice the blinking light and then reset it to restart it

8. Blinking Lights with Daikin Air Conditioner Fault Codes

Sometimes the Daikin air conditioner won’t just blink but will also display an error code. In such a case, you should understand what the error code means and resolve it.

Here’s a table to guide you:

Fault Code Interpretation What To Do
U5A low battery or transmission malfunctionCheck the remote control to ensure its working
U0/E6/PORefrigerant leak Check the refrigerant level
A5Clogged filter Clean the air filter
UH/U7Faulty wiring/power cordCheck the power cord and wiring

Closing Remarks 

Now you have a quick Daikin air conditioner troubleshooting guide to use when your air con fails or won’t work correctly. Thus, consider using it before calling Daikin or your local HVAC technician.

After all, Daikin encourages DIY troubleshooting on their websites, and that’s why you’ll get lots of guides and manuals. 

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