Drain Water Level System Abnormality

What it means

This code appears on Daikin air conditioners, most often on ducted and cassette units fitted with a drain pump and float switch. It means the condensate level in the indoor drain pan has risen too high or the drain system is not working properly. The unit stops cooling to prevent water leaks, 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: A1A6A5

Symptoms4

• Cooling stops and code A3 appears.
• Water leaks or drips from the indoor unit or around a ceiling cassette.
• The drain pump runs constantly or is not heard at all.
• A damp or musty smell near the indoor unit.

Possible causes6

• A drain line or drain pan blocked by dust, algae and sludge.
• A failed or weak drain pump on units fitted with one.
• A float switch that is stuck, dirty or faulty.
• Wrong drain line slope, or a lift after the pump higher than the installation manual allows.
• A loose drain pump or float switch connector on the board.
• A faulty indoor PCB, which is the least common cause.

How to diagnose5

1. Switch the unit off at the breaker before any check.
2. Check the drain outlet outside or at the waste point and confirm water flows out freely.
3. A technician opens the unit and inspects the drain pan for standing water or dirt.
4. The technician pours water into the pan and watches the drain pump run and empty it.
5. The technician checks the float switch movement and connector, and the drain slope and lift against the installation manual.

How to fix5

1. Flush the drain line and pan and clear the blockage.
2. Clean and free a stuck float switch, and replace it if faulty.
3. Correct the drain line slope or routing so water flows without pooling.
4. Replace the drain pump if it does not run or pumps weakly.
5. Run the unit in cooling for an hour and confirm water drains and the code does not return.

Repair cost

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

A drain line cleaning is the cheapest and most common fix; the cost rises when the drain pump or float switch must be replaced or a ceiling unit is hard to reach.

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