Daikin Air Conditioner Error Code U
1. Error Code U0
+ Error Name: Low Refrigerant Warning.
+ Causes and Solutions: Low refrigerant or gas leakage (pipeline construction error); temperature sensor malfunction (R4T, R7T); low pressure sensor malfunction; outdoor unit circuit board malfunction.
2. Error Code U1
+ Error Name: Phase Reversal, Phase Loss.
+ Causes and Solutions: Power supply phase reversal; power supply phase loss; outdoor unit circuit board malfunction.
3. Error Code U2
+ Error Name: Insufficient Power Supply or Rapid Voltage Drop.
+ Causes and Solutions: Insufficient power supply; instantaneous power supply failure; phase loss; Inverter board malfunction; outdoor unit control board malfunction; main circuit wire failure; compressor malfunction; fan motor malfunction; signal transmission wire failure.
4. Error Code U3
+ Error Name: Operation Check Failure.
+ Causes and Solutions: Perform system check again.
5. Error Code U4
+ Error Name: Signal Transmission Failure Between Indoor and Outdoor Units.
+ Causes and Solutions: Wiring between indoor-outdoor units, outdoor-outdoor units cut, short circuit, or incorrectly connected (F1, F2); outdoor or indoor unit power loss; incompatible address system; indoor unit circuit board malfunction; outdoor unit circuit board malfunction.

6. Error Code U5
+ Error Name: Signal Transmission Failure Between Indoor Unit and Remote Control.
+ Causes and Solutions: Check signal transmission between indoor unit and remote control; recheck settings if one indoor unit uses two remotes; remote control board malfunction; indoor unit circuit board malfunction; possible interference.
7. Error Code U7
+ Error Name: Signal Transmission Failure Between Outdoor Units.
+ Causes and Solutions: Check connection between outdoor unit and C/H control adapter; inspect signal wires between outdoor units; check outdoor unit circuit board; C/H control adapter malfunction; incompatible C/H control adapter; incorrect address (outdoor unit and C/H control adapter).
8. Error Code U8
+ Error Name: Signal Transmission Failure Between Main and Sub Remotes.
+ Causes and Solutions: Check signal transmission wire between main and sub remotes; remote control board malfunction; auxiliary control connection failure.
9. Error Code U9
+ Error Name: Signal Transmission Failure Between Indoor and Outdoor Units in the Same System.
+ Causes and Solutions: Check internal and external signal transmission wires in the system; inspect electronic expansion valve on the indoor unit of the system; system indoor unit circuit board malfunction; connection failure between outdoor and indoor units.
10. Error Code UA
+ Error Name: Exceeding the Number of Indoor Units.
+ Causes and Solutions: Check the number of indoor units; outdoor unit circuit board malfunction; incompatibility between outdoor and indoor units; failure to reset the outdoor unit when replacing; duplicate addresses on central remote; verify system addresses and reset if necessary.

11. Error Code UE
+ Error Name: Signal Transmission Failure Between Central Control Remote and Indoor Unit.
+ Causes and Solutions: Check signal between indoor unit and central control remote; master control signal transmission failure; central control board malfunction; indoor unit circuit board malfunction.
12. Error Code UF
+ Error Name: Improper Installation of Cooling System, Incompatible Control Wiring / Gas Line.
+ Causes and Solutions: Check signal between indoor and outdoor units; malfunctioning indoor unit board; unclosed shut-off valve; failure to perform system check.
13. Error Code UH
+ Error Name: System Malfunction, Gas System Address Undefined.
+ Causes and Solutions: Check signal between outdoor unit-indoor unit, outdoor unit-outdoor unit; malfunctioning indoor unit board; malfunctioning outdoor unit board.
Error Code P Daikin Air Conditioner
1. Error Code P4
+ Error Name: Inverter Heat Sink Temperature Sensor Malfunction.
+ Causes and Solutions: Malfunction of heat sink temperature sensor; Inverter circuit board malfunction.
2. Error Code PJ
+ Error Name: Outdoor Unit Power Setting Error.
+ Causes and Solutions: Failure to set outdoor unit power; Incorrect outdoor unit power setting when replacing the outdoor unit board.

Error Code F for Daikin Air Conditioners
1. Error Code F3
+ Error Name: Abnormal Discharge Pipe Temperature
+ Causes and Solutions: Connection error of the discharge pipe temperature sensor; Discharge pipe temperature sensor malfunction or misplacement; Outdoor unit board malfunction.

To check what exact error your Daikin air conditioner is facing, press and hold the Cancel button on the remote for 5 seconds or until the display shows code 00. Continue pressing Cancel one click at a time (do not hold) to cycle through the error codes. When the error code appears along with a beep, that is the Daikin air conditioner error code.
Explore some of the standout Daikin air conditioner models available today: Daikin Inverter 1 HP FTKB25WMVMV; Daikin Inverter 1.5 HP FTKB35WMVMV; Daikin Inverter 2 HP FTKY50WVMV; Daikin Inverter 1 HP ATKC25UAVMV; Daikin Inverter 1.5 HP FTKA35VMVMV; Daikin Inverter 2.5 HP FTKY60WVMV…