Outdoor PCB Defect

What it means

This code appears on Daikin split, ducted and cassette air conditioners and means the outdoor unit's control board has detected an internal fault that prevents it from running the compressor and fan safely. Cooling stops completely, and the same code can mean something else on other brands.

Models covered: Daikin split air conditioners and Daikin ducted/cassette (SkyAir) units, which share the same error code system; the code shows on the wired remote or via the wireless remote check function.

Related codes: U4U2L5H8

Symptoms4

• The indoor unit runs fan-only with no cooling and E1 appears.
• The outdoor unit does not start at all, or runs for seconds and stops.
• The code may return right after a restart.
• A burning smell or heat marks near the outdoor unit in some cases.

Possible causes5

• A temporary error from a voltage fluctuation or sudden power cut.
• A failed outdoor board damaged by high heat, overvoltage or moisture.
• A loose or burnt connector on the outdoor board.
• Insects or heavy dust inside the outdoor electrical box.
• Board damage caused by another failure such as the compressor or fan.

How to diagnose5

1. Switch the unit off at the breaker for several minutes, restart and watch for the code.
2. Check that the supply voltage is stable and a suitable protector is fitted.
3. A technician inspects the outdoor board only after isolating power and waiting for the capacitors to discharge, because an inverter board keeps a dangerous charge.
4. The technician checks the connectors and looks for insects or burn marks.
5. Before replacing the board, the technician checks the compressor and fan so the new board is not damaged by the same cause.

How to fix5

1. Restart the unit after a power reset; if the code never returns, a brief glitch was the likely cause.
2. Fit a voltage protector if the supply is unstable.
3. Clean the electrical box and repair burnt or loose connectors.
4. Replace the outdoor PCB with a genuine part matching the model at an authorized service center.
5. Run and test the unit under load and confirm the code does not return.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

A reset or connector repair is cheap, while an outdoor inverter board is one of the most expensive parts of the unit and its price varies widely by model.

Prices are rough estimates including the part and the technician’s fee, and vary with brand, model and part source.
Prices last updated: September 2026

Frequently asked questions