U5 error code might appear on Daikin wired remote, when Daikin wired remote is connected/disconnected, or our CoolPlug is connected/disconnected This error can be easily overcome by resetting pow...

Power supply fault, capacitor wiring error · • · • · • · • · U3 · Check operation not executed Check operation not carried out at · commissioning or after main PCB replaced · • · U4 · Communication failure, between indoor & outdoor · Wiring fault, defect of PCB, pump wired · across communication wiring · • · • · • · • · • · U5 ·

transmission error · Check operation is not executed. k k k k k k k · U4 · Malfunction of transmission · between indoor and outdoor unit · Short circuit in indoor-outdoor or outdoor-outdoor · transmission wiring (F1 / F2), or wrong wiring · Outdoor unit power supply is OFF · System address does not match · Defective indoor unit PCB · Defective outdoor unit PCB · k k k k k k k · U5 ...

July 20, 2025 - Easily identify Daikin HVAC system faults with this complete list for simple self-diagnosis & troubleshooting. Includes VRV, SkyAir, HRV systems, and more.

April 2, 2026 - U5 – Communication error between indoor unit and remote controller – A possible mistake with the interconnection wires, or a PCB fault with the indoor/outdoor remote controller.

December 22, 2022 - U0 System Shortage of refrigerant or EEV failure U1 System Negative phase, Open phase U2 System Power supply insufficient U3 System Wiring check operation not executed U3 System Mismatch of indoor and outdoor units – Split only U4 System Transmission between indoor units U5 System Transmission to remote controller U6 System Malfunction transmission outdoor to BP unit U7 System Transmission between outdoor units U8 System Transmission between master and slave RC U9 System Transmission error between indoor to outdoor UA System Excessive number of fancoils UC System Address duplication of central controllers UE System Transmission error between indoor and central UF System Refrigeration system not set wiring – piping UF System Terminals 1 and 3 crossed (Split Skyair) UH System System error Refrigeration system set up

October 28, 2025 - An overloaded compressor can either be from lack of maintenance or there’s an issue with the sensor (or the wiring) that reads the overload. To fix an E5 error, performing a compressor chemical wash (for an initial price of $80) might do it.

A Daikin technician came over and reset it in like 5 sec by just long pressing the Mode selection button...

By checking the error code, you are able to identify the status and the issue of the air conditioner/air conditioning system.

February 24, 2025 - Fault U5 is a Transmission error between indoor unit and remote controller. For more information open the Daikin Service App on your mobile. 1. Ensure you are logged into the Daikin Service App. You will see Engineer as below. 2. Click on the related product group.

November 10, 2025 - 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. The code indication changes as shown below, and notifies with a long beep. While a reset can fix minor issues, more complex problems with your Daikin air conditioner might require expert attention.

The error code #21 comes up on the controller. I was told this was due to not enough air getting to the unit. I have ... Disclaimer: The customer and expert messages presented herein may have been altered or modified to enhance readability and safeguard the privacy of individuals. These modifications do not change the intent or substance of the original messages. ... U5 error often relates to communication failures or outdoor unit shutdowns in the 24k system.

Complete Daikin error code list for mini-splits, VRV systems, and air conditioners. Find meanings, causes, and troubleshooting solutions for all Daikin fault codes.

May 2, 2023 - Download the app here if you are yet to do so. ... (2) Press CANCEL button for about 5 seconds while pointing the remote control at your indoor unit. The screen/display on your remote controller will now show an error code (and beep)

May 16, 2024 - Indoor Group Address (centralized address) is required for proper CoolMasterNet operation. Without Group Address Indoor unit is not visible and can not be controlled by CoolMasterNet or any other Daikin equipment. Group Address is set with wired remote controller.

April 22, 2026 - Complete Daikin error code list with clear meanings, causes, and fixes. Diagnose your AC step by step and know when to call HVAC repair.

January 22, 2026 - The list below features all the malfunction error codes for Daikin air conditioners and their potential causes.

The electronics involved are complex due to that error code. This is not a repair suitable for DIY. The good news is that Daikin was the pioneer in these types of systems and is significantly better than others, with their dealers generally being very competent.

April 21, 2026 - 💡 How to Check Your Daikin Error Code Using the Remote: Hold the “Cancel” button for about 5 seconds until you hear a beep and “00” flashes on the screen. Press “Cancel” repeatedly to cycle through the codes. When you hear a long, continuous beep, that is your correct error code. ⚠️ Pro Safety Tip: While issues like cleaning blocked filters to stop a freeze-up (A5) or topping up refrigerant (U0) are straightforward fixes, errors involving the inverter PCB (L1), reverse phase wiring (U1), or Intelligent Power Module protections should always be handled by our licensed HVAC technicians.