Daikin Error Code A1 — What It Means & Fix

What Does This Error Mean?

Daikin Error Code A1 means the indoor unit main PCB (printed circuit board) has detected a fault. Try a power reset first — turn the AC off at the isolator for 5 minutes and restore power. If A1 returns, a Daikin-certified technician must diagnose and replace the indoor PCB.

Affected Models

Daikin Cora Series
Daikin Alira X
Daikin US7
Daikin FTXM Series
Daikin Zena

Common Causes

Indoor unit main PCB failure
Communication error between indoor PCB and remote control receiver
Voltage spike or power surge damaging indoor electronics
Wiring fault between indoor and outdoor unit

How to Fix It

Perform a power reset.

Turn the air conditioner off using the remote or wall controller. Turn off the indoor unit's circuit breaker or isolator for 5 minutes. Restore power and switch the unit on. If A1 does not return, the error was caused by a transient fault.
Check the display panel wiring.

On split system models, the display PCB inside the indoor unit connects to the main PCB via a ribbon cable. Loose ribbon cables can cause A1 errors. This check requires opening the indoor unit — only do so if you are comfortable with electrical appliances and the unit is isolated.
Note any accompanying symptoms.

If A1 appeared alongside unusual smells, burning odours, or after a power surge, report these symptoms to the technician. Burning smells from the indoor unit can indicate a capacitor failure on the PCB.
Contact a Daikin-authorised service agent.

Use the Daikin service locator to find a licensed technician. Indoor PCB replacement on Daikin models is a relatively common and straightforward repair for experienced refrigeration technicians.
Check warranty status.

Daikin split systems typically carry a 5-year parts and labour warranty when installed by a licensed contractor. Check your installation paperwork or the Daikin website to confirm whether your unit is still under warranty before paying for parts.

When to Call a Professional

If a power reset does not clear A1, the indoor unit PCB has failed. Contact a Daikin-authorised service agent — the indoor PCB must be replaced by a licensed technician.