mypros+
Error code reference

Daikin Air Conditioner Error Code A3

Drain water level system abnormality

Daikin codesDaikin air conditioner codes
Avg. service call
$285
National average. Trip fee plus diagnostic plus labor. Before parts.
MyPros+ 3-day pass
$9.95
Same diagnostic steps, on your phone. Start now.
You keep in your pocket
~$275
Even before you buy the part.
Skip the service call. Fix it yourself.
Full procedure unlocks instantly.
Get Started

What the A3 error code actually means

Your Daikin air conditioner detected that water inside the unit has built up to a level that could cause it to overflow, so it shut itself down to prevent water damage to your home. This is usually caused by a clogged drain line or a problem with the small pump that removes condensation water. The unit will not restart until the water level drops and the underlying issue is resolved.

Diagnostic procedure

The full A3 procedure

Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.

MyPros+ · DiagnosticsStep 1 preview
1
First diagnostic step
Check if drain pump mechanism is connected; check short circuit connector X15A on PCB.
Unlock with pass
Unlock with pass
Unlock with pass
More steps, wiring diagram references, and verified part numbers
Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.
Unlock A3 procedure $9.95

Or subscribe: $29/month for unlimited access to all codes plus Max AI diagnostics.

Most common causes of A3

Ranked by how often they cause this code
  1. 1Missing or disconnected short circuit connector X15A
  2. 2Clogged or obstructed condensate drain line
  3. 3Failed or disconnected drain pump
  4. 4Float switch stuck in raised position
  5. 5Improperly pitched drain line

Most DIYers save hundreds by diagnosing before ordering parts.

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass

Questions people ask about A3

What does A3 mean on a Daikin air_conditioner?
The A3 code indicates a drain water level system abnormality. Specifically, the float switch inside the drain pan has detected that condensate water has reached its upper limit. Daikin units display this code and shut down to prevent overflow and water damage. The root cause can be a genuine drainage problem or a wiring issue with connector X15A on the PCB.
Is it safe to keep running my Daikin air conditioner with an A3 error?
No, you should not attempt to bypass or ignore the A3 error. The unit shuts down automatically to prevent condensate water from overflowing the drain pan, which can cause ceiling damage, mold growth, and electrical hazards. Resolve the drainage issue before restarting the system.
How much does it cost to repair an A3 error on a Daikin air conditioner?
Repair costs vary depending on the cause. Clearing a clogged drain line is a straightforward service call, typically in the range of $75 to $200 including labor. Replacing a failed condensate pump can run $150 to $400 depending on the pump model and labor rates in your area. Replacing a faulty float switch is generally less expensive, often $100 to $250 for parts and labor combined.
How do I fix an A3 error on my Daikin air conditioner?
Start by checking connector X15A on the indoor unit PCB to confirm it is securely seated, particularly if no drain pump is installed. Next, inspect the condensate drain line for blockages and flush it clear if needed. If a drain pump is part of the system, verify it is connected and operational. Once the water level drops and the underlying cause is corrected, the error should clear.
Will resetting my Daikin unit clear the A3 error code?
A power reset may temporarily clear the fault display, but the A3 error will return quickly if the underlying cause is not addressed. If the drain pan still contains standing water or the drain pump is not functioning, the float switch will activate again as soon as the unit begins producing condensate. Diagnose and fix the drainage problem first.

Related Daikin air conditioner error codes

All Daikin air conditioner codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass