Refrigerant Shortage

What it means

This code appears on Daikin split, ducted and cassette air conditioners and means the unit has concluded from its temperature, current and pressure readings that the refrigerant charge is too low. It stops the compressor to protect it, and a low charge almost always means a leak that a licensed technician must repair before recharging. 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: E4F3A5E9

Symptoms4

• Cooling weakens gradually over weeks, then U0 appears.
• Air from the indoor unit is not cold enough.
• Frost on the outdoor service valves or the thin pipe in some cases.
• The compressor runs for long periods without cooling the room.

Possible causes5

• Leaks at the pipe joints at the indoor or outdoor unit from poor flaring or tightening.
• Leaks in the evaporator or condenser from corrosion.
• An undercharge at installation, or long pipe runs without the extra charge required.
• A service valve not fully open, giving the same symptoms as a shortage.
• An electronic expansion valve or thermistor fault making the system read a false shortage.

How to diagnose5

1. Switch the unit off, avoid repeated restarts, and clean the filters to rule out an airflow problem.
2. A technician confirms the service valves are fully open.
3. The technician measures pressures and pipe temperatures against Daikin specifications and the unit nameplate.
4. The technician searches for the leak with an electronic detector or soap solution, focusing on joints and oil stains.
5. The technician checks the electronic expansion valve and sensors if pressures are normal.

How to fix5

1. Open the service valves fully if they are partly closed.
2. A licensed technician remakes the leaking flare joint or repairs the leak point.
3. The technician evacuates the system with a vacuum pump, then charges the correct refrigerant type to the nameplate amount plus any extra for long pipes.
4. Replace the evaporator, condenser or expansion valve if the leak or fault is there.
5. Run the unit, check pressures and cooling, and recheck after a few days to confirm there is no leak.

Repair cost

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

The cost is lower when the leak is at an easy-to-fix joint, and rises when brazing, a coil replacement or a large charge is needed.

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