Daikin Error Code E1 — What It Means & Fix

What Does This Error Mean?

Daikin Error Code E1 means the outdoor unit main PCB (printed circuit board) has detected a fault. This is not a DIY repair — power off the system at the isolator and contact a Daikin-certified technician.

Affected Models

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

Common Causes

Outdoor unit main PCB failure
Faulty connection between indoor and outdoor unit wiring
Power supply voltage fluctuation damaging the PCB
Moisture ingress into the outdoor unit control board

How to Fix It

Turn the system off at the isolator.

Locate the outdoor unit isolator switch — a lockable switch on the wall near the outdoor unit. Switch it off to fully cut power to the outdoor unit. Do not attempt to restart the system — continued operation with a PCB fault can cause further damage.
Check the power supply.

Confirm the AC is receiving stable power — voltage fluctuations and power surges are a common cause of Daikin PCB failures. If the E1 followed a power outage or storm, mention this to the technician.
Note the full error code sequence.

Some Daikin models display a flashing LED sequence rather than a number — count the flashes and note the pattern. E1 on the indoor display may show as a specific flash code on the outdoor unit. Provide this information to the technician for faster diagnosis.
Check for visible damage at the outdoor unit.

Inspect the outdoor unit for water ingress, insect nests in the control box, or damaged wiring. Do not touch internal components. Report any visible issues to the technician.
Contact a Daikin-authorised service agent.

Daikin E1 requires PCB diagnosis and likely replacement. Use the Daikin website's service agent locator to find a licensed technician in your area. Attempting PCB repair without refrigeration licensing may void your warranty.

When to Call a Professional

Error E1 is an outdoor PCB fault and cannot be resolved without specialised refrigeration tools and replacement parts. Turn off the system at the isolator switch and call a Daikin-authorised service agent.