Daikin air conditioner flashing green light U4 [Fixed]

As an Amazon affiliate, we earn a commision from qualifying purchases.

if your Daikin AC is flashing error code and a green light is simultaneously blinking, then you can quickly repair your AC by trying the following repairs..

Daikin air conditioner flashing green light U4 – meaning of Daikin AC error code U4 and how to fix Daikin VRV U4 error code

The Daikin u4 error code simply says that your Daikin air con dust box is dirty and you need to clean it well.

In other words, the reason why your  Daikin aircon is blinking the green light  and displaying U4 fault code is to communicate to you that it is time to do the important maintenance chore of cleaning its dust box.

Indeed, that green light that you’re seeing flashing is the cleaning (mould proof) lamp, which only starts to blink when the dust box (streamer unit) is full of dirt/dust.

Needless to say, such dust build-up makes the system work harder to cool, which can lead to a lot of Discomfort for you and other occupants of the room.


Daikin air conditioner flashing green light U4 (How to fix Daikin error code U4 and Daikin blinking green light)

You by now know that the solution to the problem of your Daikin air conditioner flashing green light and throwing error code U4 is cleaning its dust box.

So below is how you can do that:

Removing the streamer

Bear in mind that you can remove your AC’s streamer unit without first removing the AC’s front panel

error code u4 daikin

Removing the dust box

daikin vrv u4 error code

1.       Start by sliding the left and right knobs(on dust box)inward and removing the dust box

2.       Slide the cover(to the left) and un-lock it.

3.       Turn the cover then open dust box.

4.       Pull out dust brush.

daikin u4 error code reset

Remember you need to un-plug it from power(you can flip circuit breaker off as well) before you start to clean the dirty dust box.

Note that it is a must you reset the green lamp after you have cleaned the dust box. 

Below is how to do that quickly:

  1. After cleaning dust box, connect power cable back to your AC’s outlet or flip your AC’s circuit breaker back on.
  2. Next, with your AC off, go ahead and press and then hold onto the filter cleaning light reset button for around 2 seconds.

That resets the AC filter and the green warning light should go off.

Make sure you wait for like 10 minutes (or more) after turning off power supply before disassembling work.


Daikin AC flashing green light – final thoughts

Daikin error code u4 can also mean the outdoor unit of the AC can’t communicate with the system’s indoor unit.

This is, in general, caused by a problem in the wiring so disassemble it to access the PCB and see if all the wiring is fine.

Otherwise, it can be due to a defective control board which means you may need to spend on a replacement (if your parts warranty is expired).

Below is a good YouTube video to help you troubleshoot Daikin air conditioner flashing green light U4 fault if cleaning the dirt box did not work.



Daikin air conditioner not turning on [What to check]

Daikin air conditioner fault codes, meaning, and fixes

Daikin thermostat reset – step by step instructions

Is it necessary to clean ac outdoor unit? 

Leave a Comment