Is your Daikin Air Conditioning displaying fault codes? Do you want to know how you can fix them?
Booth AC is here to provide expert advice on the most common Daikin air conditioning fault codes.
In this blog post, we at Booth Air Conditioning will guide you through the top five most common Daikin air conditioning fault codes, explaining what they mean and providing insights on how to address these issues effectively.
Most Common Daikin Air Conditioning Fault Codes
Fault Code: J6
Description: Abnormal resistance of the outdoor heat exchanger thermistor.
Impact:
The outdoor heat exchanger thermistor monitors the temperature of the heat exchanger to ensure the system operates efficiently.
If the thermistor is faulty, short-circuited, or the cable is disconnected, the air conditioner may not properly regulate cooling or heating, leading to inefficiencies in operation. This can result in poor temperature control, system shutoffs, or the unit running in a limited capacity.
Causes:
- Faulty thermistor.
- Short-circuited thermistor.
- Disconnected or damaged wiring to the thermistor.
Fix:
- Inspect the outdoor heat exchanger thermistor for physical damage or disconnection.
- Test the thermistor’s resistance using a multimeter. Replace it if the reading is outside the manufacturer’s specified range.
- If the thermistor and wiring are intact, inspect the control board for issues and replace it if necessary.
Fault Code: U4
Description: Communication error between indoor and outdoor units or between outdoor and BS units.
Impact:
The communication between indoor and outdoor units is vital for synchronised operation.
A U4 error indicates a disruption in this communication, which can prevent the system from functioning properly.
It may cause the unit to stop working, reduce cooling or heating efficiency, or make the unit unresponsive.
Causes:
- Incorrect wiring between indoor and outdoor units.
- Faulty indoor or outdoor PCB (Printed Circuit Board).
Fix:
- Check and verify the interconnection wiring between the indoor and outdoor units. Ensure the cables are properly connected, and the wiring is correct according to the system’s wiring diagram.
- Inspect both indoor and outdoor unit PCBs for signs of damage or malfunction. Replace faulty PCBs if needed.
Fault Code: U5
Description: Communication error between the indoor unit and the remote controller.
Impact:
A U5 error can cause the remote controller to lose communication with the indoor unit, making it impossible for the user to control the air conditioning system.
The unit may continue operating on its last settings but without user input, or it may fail to respond entirely.
Causes:
- Incorrect or faulty wiring between the indoor unit and the remote controller.
- Faulty PCB in either the indoor unit or the remote controller.
Fix:
- Inspect the interconnection wiring between the remote controller and the indoor unit for loose connections or damage.
- Check for wiring mistakes, such as crossed wires that may interfere with communication.
- Test the remote controller on another indoor unit if possible. If the problem persists, replace the remote controller or its PCB.
Fault Code: AH
Description: Dust collector error.
Impact:
The dust collector is responsible for keeping the air clean by trapping dust particles.
If there is a fault with the dust collector, or if it becomes excessively dirty, the air quality in the space could deteriorate. This might also put extra strain on the system, reducing its efficiency and potentially causing it to overheat or shut down.
Causes:
- Malfunctioning dust collector.
- Dust collector elements are dirty or clogged.
Fix:
- Clean the dust collector and its components. This may involve removing filters and cleaning them thoroughly.
- If cleaning does not resolve the issue, inspect the dust collector’s electrical connections or sensors for faults.
- Replace any damaged or non-functional parts of the dust collector.
Fault Code: AJ
Description: Capacity setting error.
Impact:
The capacity setting determines how the air conditioning system matches the room or building’s heating or cooling load.
A capacity setting error could lead to an imbalance, where the system either overworks or underperforms, leading to inefficient temperature control or increased energy consumption.
Causes:
- Incorrect capacity or address setting during installation or configuration.
Fix:
- Verify the capacity settings in the system’s control panel or configuration menu. Make sure they match the size and type of the installed units.
- If the settings are incorrect, reset them to the proper values according to the system’s specifications.
- In case of address setting errors, check the DIP switches or configuration tools and ensure all devices have unique addresses.
Contact Us
Booth AC is a leading provider of air conditioning maintenance in Manchester and the north-west
Our expert maintenance services are relied upon by over 350 organisations each year to care for thousands of systems.
For more information on the most common Daikin air conditioning fault codes, contact Booth Air Conditioning by calling 01706 769282 or emailing sales@booth-ac.com.
