Most ACs have a digital display panel in the indoor unit. This panel is there to convey important information such as the temperature setting, timer or different modes such as a fan or cool modes. But sometimes you will also see some codes that are generally 2 alphabets or 1 alphabet and 1 number like CH or F5 etc.
These codes are generally displayed when there is any small or big problem with the AC. This is because the codes are issued by the manufacturer to represent the reasons why your AC is malfunctioning. For example, a CH pop up on your display screen means that the air filters of the Ac are clogged and you need to clean it.
These codes will help you understand which part of your AC is not functioning properly which will, in turn, allow you to talk to the repairing expert or even solve the problem yourself. You can also use these codes to gauge if the problem in your AC is major or minor.
In today’s article, we have listed some of the common codes that pop up in a Daikin AC. Go through each one of them to find out what they represent;
00: If 00 pops up in the display then your system is normal. This means that there is no error in your system. If your AC is facing some problem, then it is due to a unique error that has not been predetermined by the manufacturer. In this case, you need to talk to a technician to figure out where the problem might be.
UA: This code in a Daikin AC means that there is a power supply issue. This generally represents that there is a problem with the power supply in either the indoor or the outdoor unit. You can check the power outlet of the AC to see if there is a proper supply of power to the AC. Other reasons might:
- Faulty or defective PCB. The circuit board or the PCB of the AC is either not installed correctly or is not working properly anymore. This will disrupt the power supply and you will get the UA code error.
- This can also happen if the refrigerant used in the indoor unit is different from the outdoor unit
- This might also occur if there is a lack of compatibility between the indoor or outdoor unit. If you have recently changed any part of the AC and this code pops up then it means that the new part is not compatible with the AC and you need to get it replaced.
U0: This code means that there is a shortage of refrigerant in the ac. This might be due to a couple of reasons:
- There is a refrigerant leakage in the AC. You should call a technician soon because refrigerant can be toxic if inhaled for a long duration.
- There is something wrong with the thermistor. The thermistor is the brain of the AC and this controls the temperature of the room according to your input. A defect in the thermistor will also prompt the U0 error code
- If the PCB in the outdoor unit is not working properly then also this error code will pop up
- A low-pressure sensor measures the pressure in the refrigerant to ensure that it moves smoothly. If this sensor is damaged then also it will prompt a UO error because your Ac will detect a low refrigerant level.
U2: U2 error is also related to power supply issues. But here the issue lies with abnormal power supply. If there is a sudden increase or decrease in the power supply then U2 error will pop up. This error will also happen if there is a sudden power failure in your home. Similarly, a defective main circuit wiring will prompt an abnormal power supply within the AC which will result in the U2 error code.
U4: This code generally pops up when there is an issue with the transmission between outdoor and indoor units. This could be because of the following reasons:
- There is a short circuit between the wiring of the indoor and outdoor unit.
- The outdoor unit is switched off, check to see if the power is on
- It can also be because the PCB of either the outdoor or indoor unit is not working properly
- You need to check the connection between the two-unit to ensure that there is a smooth network between the two
A1: This problem arises when there is a PCB error in the indoor unit of the AC. In this case, you need to get the PCB repaired or replaced by a professional.
A5: This error could be due to a couple of reasons. But in general, it is because there is high-pressure control in heating or if there is a freeze-up protection control in cooling.
- This could be due to a short circuit in the indoor unit of the AC
- You could also clean the air filters in your indoor unit as a dirty and blocked air filter can also cause disruption in the pressure control or cause freezing.
- There could also be an issue with the thermistor in the indoor unit
For all the above problems you need to get it checked with an expert.
A6: This is related to the fans of the AC. When the motor of the fan is malfunctioning then you get the A6 error. This malfunction in the motor of the fan could be due to the following reasons:
- Indoor unit PCB is not working properly
- The wires of the fan could be broken or there could be a short circuit in the fan motor
- There could also be a disconnection in the fan motor harness which could result in improper fan motor functioning.
C4: C4 error generally occurs when there is a problem with the refrigerant lines inside the AC. To be specific, when the temperature sensor or the thermistor for the refrigerant starts malfunctioning, it disrupts the refrigerant movements which in turn displays the C4 error. There could also be a couple of other reasons for this error:
- The PCB of the indoor unit is not working properly
- The connectors might be disconnected
- The thermistor is malfunctioning
C9: This is very similar to the C4 error but here the defect lies in the thermistor of the suction air instead of the refrigerant lines. But the issues could be the same i.e. an indoor PCB error or the connectors disconnection will also cause this error to pop up. There could also be a simple malfunction in the thermistor that is causing the problem.
E1: If the PCB or the circuit board on the outdoor unit is damaged then you will see this error code. You need to either get it repaired or replaced. The problem could also be because the outside or inside relay wires have a connection error.
E5: This could be an overheating issue. This could also be due to an inverter, compressor or motor defect. The reasons for this can range from defective inverter PCB to inverter compressor lock issues and more. It is safe to say that you need to get it checked by a technician in order to resolve the issue.
E6: The E6 error might be due to issues with the compressor of the AC. It could also be due to a defect in the outdoor PCB. If the stop valve which connects the indoor and outdoor unit is not completely opened then also the E6 error will be prompted.
E7: This happens when the fan system in the outdoor unit is facing some problems. This could be due to a malfunction in the motor or if the blades of the fan are blocked by something. You can easily check the fan of the outdoor unit to see if there is something stuck in the blade or not.
The problem will also arise if the fan motor and the PCB of the outdoor unit do not have a smooth connection.
E8: This error relates to either the outdoor inverter or compressor. The problem could be a malfunction in the compressor or if the PCB of the outdoor unit is not working then also the E8 error will pop up. The problem could also lie with the power transistor or the main circuit capacitor.
F3: F3 error occurs when the temperature of the discharge pipe becomes either too low or too high. It can also be due to a problem in the thermistor of the discharge pipe. A defective outdoor PCB or connector will also result in an F3 error.
F6: This could be because of the abnormally high pressure inside the AC unit. The problem could also occur if the refrigerant is being overcharged. Outdoor PCB defects will also cause this error. There could be a problem with the thermistor which will also result in abnormally high pressure inside the unit.
H0: H0 refers to the malfunction in the sensor system of the compressor. This could be the result of a defective PCB or a faulty connection. You need to get the compressor checked or replaced as need be, to resolve the issue.
H6: Here the problem could be either a defective PCB or the compressor. Either of these results in malfunction of the position detection centre which will prompt the H6 error. This could also be from an unstable cable or compress.
H8: The compressor unit (CT) system is not functioning properly. This could be because of a faulty power transistor or reactor. If the wiring system of the inverter is faulty then this code might be displayed. If the power transistor is not working then also this error will be displayed.
H9: This is an air thermistor problem, the issue lies with the outdoor thermistor. It could also be because the connection to the thermistor is damaged or the PCB in the outdoor unit is not working properly.
J3: This code will be displayed when the thermistor of the discharge pipe is malfunctioning or if the connection of the thermistor is disrupted. It could also be if the outdoor PCB is malfunctioning.
J6: Like the H9 error this is also an air thermistor problem and could be because of a defective thermistor or if the connection of the thermistor is interrupted. A damaged PCB will also cause this error.
L3: This could be because of multiple reasons like:
- Defective outdoor fan motor
- Defective PCB or power transistor
- Outdoor PCB malfunctions
- Abnormal temperature rise due to short circuit
L4: This is possible if the Fin temperature rises due to the malfunction of the inverter. The rise in the fin temperature could be because of a short circuit or if the fin thermistor is not working properly.
L5: If there are any issues with the compressor coil such as disconnected wiring or insulation failure then the L5 error code will pop up. This error will show if the compressor is not starting up properly or the inverter PCB is malfunctioning.
P4: If the thermistor that measures the radiation fin temperature is malfunctioning then also the P4 error code will be displayed. Any malfunction in the PCB of the inverter will also give this error code. It could also be due to a defective fan motor or compressor. The radiation fin thermistor malfunctions also sometimes result in the P4 error code.
There are so many codes in the above list where the issues or problems are similar or even the same. The codes are there only to narrow down the reasons that might be causing issues in the AC but they do not pinpoint the exact reason why the problem is occurring. Further diagnosis should be done by AC repairing experts to resolve the issue. We hope the above list at least helped you to narrow down the reason your AC is malfunctioning and talk to the expert accordingly.