Daikin code A6

Daikin A6: indoor fan motor locked, overloaded, or badly connected

Daikin A6 is the indoor fan motor entry on the malfunction chart, covering a locked rotor, an overload, and a faulty connection. Here is what separates them.

Source verifiedBy HVAC Bench Editorial DeskLast reviewed
Direct answer

What this means

Daikin lists A6 in the indoor unit division as a fan motor malfunction, described as the motor being locked, overloaded, or suffering from a faulty connection. All three are ways of saying the board commanded a fan speed and did not get the feedback it expected, so the code is about the command-and-feedback loop rather than about a burnt-out motor.

Equipment and model context

Daikin indoor units covered by the SM-TS3 malfunction chart, including room air, SkyAir, and VRV indoor equipment

  • FTXS series wall units
  • FXFQ series cassettes
  • FXMQ series ducted
  • FTXM series wall units

The definition here comes from the Daikin malfunction code chart, which is organised by division and detail code rather than by model. Indoor fan arrangements differ sharply between a wall unit, a cassette, and a ducted unit, so the mechanical cause behind the same code is model-specific and is read from that unit's service manual.

What you may notice

  • The indoor fan does not start, stops part way through a cycle, or turns briefly and then halts, with A6 displayed.
  • A rubbing, ticking, or scraping noise was audible from the indoor unit in the period before the fault.
  • Airflow from the outlet had fallen well below its usual strength at the same speed setting.

Likely causes

  • Physical obstruction can hold the fan wheel, including debris drawn in through a return path or material that has entered during building work.
  • Bearing wear or a drive component that has shifted increases the torque needed, which the board sees as an overload rather than as noise.
  • A motor connector that has loosened, corroded, or been disturbed during service interrupts the feedback the board uses to confirm rotation.

Diagnostic paths

Noise came first, then the code

In the days or weeks before A6, the indoor unit made a rubbing or scraping sound that changed with fan speed, then the fan stopped and the code appeared.

Describe the noise and when it started. A mechanical trail before an overload detection points at the fan assembly rather than at the electronics driving it.

The fan never moves at all after the code is cleared

Following a display reset, the indoor fan makes no attempt to turn at any speed setting, and the code returns immediately.

Report that the fan is fully static rather than briefly turning. A motor that does not start at all and one that starts and is judged slow are different measurements to the technician.

It followed a filter clean or a panel being opened

The fault arrived immediately after routine cleaning, a filter change, or work near the indoor unit rather than during unattended running.

Confirm every panel and filter is fully refitted and latched, then report the timing. A connector disturbed during access is a distinct possibility a technician can check first.

What the board is actually checking

Behind the code sits a loop. The board issues a speed demand, the motor responds, a feedback signal returns the achieved rotation, and a mismatch between demand and feedback raises the fault whatever caused the gap.

  1. Speed demandThe board asks for a fan speed
  2. Motor responseThe wheel accelerates or does not
  3. Feedback signalReports what the motor achieved
  4. MismatchRaises the fan motor entry
Three readings of A6 and the evidence that separates them
ReadingWhat it would sound and look likeWhat decides it
Locked rotorNo movement, possibly a humTurning resistance measured by hand at the wheel
OverloadSlow or laboured rotation, noiseCurrent drawn against the motor rating
Faulty connectionNo movement, no hum, intermittentContinuity and feedback at the board

Why a fan fault stops the whole indoor unit

It is tempting to see a stopped fan as an inconvenience rather than a fault worth halting for. The refrigeration circuit disagrees, and the reason is thermal rather than mechanical. An evaporator with nothing passing over it has no load, so its temperature collapses in cooling and its pressure climbs in heating, and each of those ends somewhere the designer did not intend.

Daikin therefore treats loss of confirmed indoor airflow as a stop condition rather than a degraded mode. That is also why A6 on one indoor unit of a multi-unit system does not necessarily stop the others: each indoor unit protects its own heat exchanger, and the outdoor unit adjusts to the load that remains.

The one observation that is genuinely yours to make

A technician arriving cold has to work out whether the motor was struggling before it stopped. Nothing in the stored fault record tells them that. An occupant who noticed a scraping noise for a fortnight, or airflow that had been weakening at the same setting, hands over a decisive piece of history, because a mechanical trail points at the fan assembly and its absence points at the electrical path.

Keep the description plain: what it sounded like, at which fan speed, and roughly when it began. Avoid guessing at parts. The blower motor definition explains what the component does and how it is driven, and the mini-split noise reference covers how to describe a sound in terms a technician can act on.

Service handoff

What to give the technician

Give the indoor model, the unit number beside A6, whether the fan moves at all, any noise history with its start date, and whether the fault followed cleaning or panel access.

Homeowner safe

Safe homeowner checks

  1. Switch the affected indoor unit off and leave it off, since running the outdoor unit against a stalled indoor coil is what the protection prevents.
  2. Confirm the filters, front panel, and any decoration panel are correctly seated and latched after recent cleaning.
  3. Write down any noise heard before the fault, the fan speed it occurred at, and roughly when it started.

Is a reset appropriate?

The code clears from the display on a power interruption, but the board re-tests the fan on the next start, so a fault that returns within seconds is reporting an unchanged mechanical or electrical condition.

Stop point

When to call a technician

  • Reaching into the fan housing, freeing a wheel, and testing motor feedback or winding condition require the indoor casing to be opened by a qualified technician.
  • Do not attempt to turn the fan wheel by hand through a grille or outlet. The blade edges and the drive arrangement are not designed for that access.

Questions people ask about this

Can a dirty filter cause Daikin A6?

A loaded filter reduces airflow but does not change what the motor achieves against its own feedback. The fan motor entry is raised by rotation that does not match the command, which a filter does not affect.

Why does the outdoor unit keep running with A6 showing?

On a multi-unit system each indoor unit protects its own heat exchanger, so one head reporting a fan fault stops itself while the outdoor unit continues serving the others. On a single-zone system the whole system stops.

Is A6 always a motor replacement?

No. The chart entry covers a locked rotor, an overload, and a faulty connection in one line. A disturbed connector or an obstruction in the wheel produces the same code with a motor that is fully serviceable.

Should I run the system in fan mode to test it?

Fan mode does put the motor under demand without running the refrigerant circuit, which is safer than a cooling call. If the fan still fails to turn, stop and leave the diagnosis to service rather than repeating it.

Evidence record

How this page was checked

service manual, official manufacturer support article · checked 2026-09-15

Every technical claim above was written from primary documentation held in the HVAC Bench evidence record: Daikin Industries and Daikin Comfort Technologies technical literature. Where a source limits a definition to certain models, test conditions, or product classes, that limit is repeated here rather than generalised.

Documentation class
service manual, official manufacturer support article
Scope of the definition
Daikin indoor units covered by the SM-TS3 malfunction chart, including room air, SkyAir, and VRV indoor equipment
Last checked
2026-09-15