Daikin | Split/ Multi Split

Error Code U1

Troubleshooting guide for the Daikin Split/ Multi Split system fault U1.

Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.

System Diagnosis

Reverse phase, open phase

Potential Causes & Solutions

  • Power supply reverse phase.
  • T phase open phase.
  • Defective outdoor unit PCB (A1P).

Diagnose with Confidence

Use the ACLogics AI assistant to walk through this error code step-by-step.

Get the App

Included in Diagnosis Workflow

1

Ask

Upload nameplate & symptoms

2

Diagnose

AI identifies error U1

3

Report

Generate professional PDF