OEM-Specific

Useful Daikin fault codes chart for working out errors

I find this useful

Daikin field settings, i always forget the remote sensor / return temp / controller temp settings

I find this very handy for checking systems, confirming BACnet settings, and configuring IP addresses on Daikin gateways.

To connect successfully:

1. Set your laptop IP address to the same subnet as the D-BACS device.

2. Connect your laptop directly to the D-BACS network or via the same switch.

3. Open the D-BACS Setup Tool and run device search.

4. The tool will discover the gateway and allow you to view or modify BACnet/IP settings.

VRV Indoor Unit Mode Control Explanation

A common issue with Daikin VRV systems is that indoor units appear to operate only in heat or cool/vent, not switching freely between all modes. This is often mistaken as a BMS control fault, but it’s typically a system design limitation.

Only indoor units connected to their own BS box can operate independently in heat, cool, or vent modes.

When multiple indoor units share a single BS box, one becomes the master unit and determines the mode for all others on that box. For example, if the master is set to heat, the others can only run in heat/vent mode.

While the BMS can sometimes manage this by using high select or mode-forcing logic, the underlying issue is usually related to poor system design, where units with different heat loads are grouped on the same BS box.

Hi everyone,

Does anyone have a Daikin fault code list they could share?

I’m currently dealing with a U4 fault and would really appreciate any advice or information on how to fix it.

I have attached an image for reference