Daikin A3 error code

What it means

A3 means the indoor unit thinks condensate water is not being removed normally or the drain level circuit cannot be trusted. Treat visible water seriously.

Urgency

Likely causes

1. Indoor/outdoor communication wiring or terminal problem
2. Loose low-voltage connector after service or vibration
3. Power interruption during the control handshake
4. Indoor or outdoor control board fault after wiring is verified

Homeowner fix

Turn the unit off if you see water at the indoor unit. Check only for an obvious blocked drain outlet or kinked external drain hose; do not open the cabinet. If water is present or A3 remains, leave it off.

When to call a pro

Call a licensed HVAC technician if water is present, the indoor head drips, or A3 returns. Tell them the code is Daikin drain level control.

Repair vs replace

Drain faults are usually repairable and rarely justify replacing the whole system unless water damage and other major failures are already present.

• Daikin AURORA 9,000 BTU R-32 208/230V (FTXV09AVJU9 / RXT09AVJU9)

  AURORA R-32

• Daikin AURORA 12,000 BTU R-32 208/230V (FTXV12AVJU9 / RXT12AVJU9)

  AURORA R-32

• Daikin AURORA 15,000 BTU R-32 208/230V (FTXV15AVJU9 / RXT15AVJU9)

  AURORA R-32

• Daikin AURORA 18,000 BTU R-32 208/230V (FTXV18AVJU9 / RXT18AVJU9)

  AURORA R-32

Parts for this line

The parts catalog for Daikin AURORA R-32 lists 7 sourced replacement parts for this product line.

For your technician

Technician note: check drain pan, float switch, drain pump where installed, connectors, and indoor PCB drain input. Page context: Daikin maps this display to the AURORA R-32 line; source: Daikin Nineteen, ATMOSPHERA, Entra, and MXM/MXT/MXTH local service manuals; display convention: match the letter A and three marker exactly before comparing neighboring codes.

Which systems show it

• Daikin current US residential R-32 ductless single-zone systems, including AURORA R-32, ATMOSPHERA R-32, Entra R32, OTERRA R-32, and Nineteen-series style high-wall diagnostics where the same Daikin A/C/E/F/H/J/L/P/U code family is used.
• Daikin concealed-duct/FDMQ indoor units where the Nineteen service manual explicitly lists the same indoor drain, fan PCB, remote-controller, and FDMQ-only C/U codes.
• Daikin AURORA Multi R-32 and Standard Multi R-32 MXT/MXTH/MXM systems where the MXM engineering manual lists the same homeowner code table.
• MXM/MXT/MXTH multi-zone systems for the additional multi-zone U-series and inverter/control codes specifically called out from the MXM manual.

Related troubleshooting

Use the symptom guide alongside the exact display code if the unit is flashing, cycling, or showing comfort symptoms.

Reset note

Turn the unit off if you see water at the indoor unit. Check only for an obvious blocked drain outlet or kinked external drain hose; do not open the cabinet. If water is present or A3 remains, leave it off.

Manual trigger

A3 means the indoor unit thinks condensate water is not being removed normally or the drain level circuit cannot be trusted. Treat visible water seriously.

Related codes

Source

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